ABSTRACTS from the 5th International Crustacean Congress

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Aguzzi, J. and Abelló, P

Insituto de Ciencias del Mar-CSIC, Barcelona, Spain

Activity rhythms of Nephrops norvegicus (Crustacea: Decapoda: Nephropidae) from a continental slope population in the western Mediterranean Sea based on time-lapse video recordings

Infrared time-lapse video recording has been used to survey the locomotor activity behaviour of freshly-collected Norway lobsters, Nephrops norvegicus, kept in the laboratory in constant conditions of temperature (14°C) and darkness during 5-7 days. The individuals used in the experiments were freshly collected by trawling on muddy bottoms off-shore Barcelona (western Mediterranean) at depths of around 450 m. A total of 17 adult males has been analysed. Most of the activity took place during the expected night-time. Several peaks of activity were often recorded within the main night activity period. Time series analysis (periodogram) has allowed detailing the precise periodicity shown by each individual. Multivariate analysis has allowed detecting similarities among individual activity rhythms based in the resemblance of the estimate forms.

Ahyong, S.T.¹ and Schram, F.R.²

¹Dept. of Marine Invertebrates, Australian Museum, 6 College St., Sydney, NSW 2010 ²Institute for Systematics and Population Biology, University of Amsterdam, PO Box 94766, NL-1090 GT Amsterdam, The Netherlands

The phylogeny of the reptant Decapoda

The high level phylogeny of the reptant decapods has been subject to much debate for more than 100 years. Not only have the relationships between decapod infraorders been disputed, but also their monophyly. Previous approaches to investigating reptant phylogeny have largely followed 'traditional intuitive' methods whilst cladistic methods have been applied to reptants only in the last decade. The present study investigates reptant relationships using cladistic analysis of morphological data. The phylogenetic position of the glypheoids, known only from fossils or the extant Neoglyphea inopinata, and enoplometopids with the single extant genus Enoplometopus, are currently controversial among carcinologists. Our present results are well resolved indicating the positions of each of the major reptant groups.

Almeida, M.J. and Queiroga, H.

Departmento de Biologia, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal

Factors that control recruitment of Carcinus maenas megalopae to an estuary (Ria de Aveiro) on the Portuguese west coast

We studied daily settlement of Carcinus maenas megalopae in the Ria de Aveiro during three months, using standard artificial settlement substrates. We identified two settlement peaks that could be related to wind forcing of shelf circulation in an oceanic eastern boundary: increasing northward component of daily wind stress was positively associated with recruitment episodes, at time lags of 1 and 6 d (p<0.005). We did not find any relation between tidal range or subtidal sea level and the input of megalopae to the estuary. Compared with decapod species from other systems, megalopae abundance in the collectors was low (daily average of 0.18 ind./collector). Given the high density of the species adult population in the Ria de Aveiro, it appears that maintenance of the population is achieved in a background of low supply of megalopae. This would imply that density-dependent post-settlement processes are less important than supply of larvae for the dynamics of the population.

Alvarez, F., Villalobos J.L. and Acuña P.

Colección Nacional de Crustáceos, Instituto de Biología, Universidad Nacional Autónoma de México, Apartado Postal 70 - 153, México 04510, D.F., México

Populations of the genus Macrobrachium with abbreviated development from Mexico: how many species are there?

With the recent discovery of 12 populations of freshwater prawns of the genus Macrobrachium with abbreviated development in southeastern Mexico, new taxonomic challenges have emerged. These populations are characterized by: small sized adults of around 6 cm of total length, small distribution areas covering a few hundred meters along a river, and the production of up to 20 large eggs from which larvae with different degrees of development hatch. The external morphology across populations is very uniform, the rostrum and second pereiopods do not offer enough characters to identify each population reliably. Two new species have been described belonging to this complex, however, the question arises of how many species are there? Three different approaches were used to compare three populations: enzime electrophoresis, adult morphometry, and larval characters. The results indicate that all the populations represent different species, a situation that could potentially double the species of Macrobrachium in Mexico.

Andersen, L.E.¹, Norton, J.H.², Levy, N.H.² and Storey, A.W.³

¹Centre of Environmental Management, University of Central Queensland, Gladstone, Queensland 4680 ²Queensland Department of Primary Industries, Oonoonba Veterinary Laboratory, Townsville, Queensland 4810 ³Zoology Department, University of Western Australia, Crawley, Western Australia 6009

Metal burdens, shell disease and immune responses in the mud crab Scylla serrata from Port Curtis, Queensland

In 1994 a previously unrecorded rust spot shell disease was observed in mud crabs (Scylla serrata - Forskal) from Gladstone (Port Curtis Harbour), Central Queensland, Australia. Rust spot lesions appear to be caused by a defect in the formation of the endocuticular layer, rather than as a result of the pathogenic cuticular degeneration observed in classic shell disease. The hepatopancreas from 105 mud crabs from both Gladstone and Ayr (control site) have been analysed for a complement of 57 different metals over two consecutive years. Although generally there was no significant difference between metal levels in the diseased compared to the non-diseased group from Gladstone, levels of Copper and Zinc were shown to be elevated in Gladstone compared to Ayr in both 1999 and 2000. Results also indicate elevated metal burdens in Gladstone crabs compared to Ayr. Higher within-group variation in metal levels of the diseased female crabs from Gladstone compared to the other groups suggest that the diseased crabs may be unable to regulate metal levels. Measures of haemolymph immune factors of the same crabs also suggest an elevated immune response from the Gladstone crabs compared to controls. The relationship between the elevated immune response, metal levels and shell disease is being further investigated.

Anger, Klaus

Biologische Anstalt Helgoland; Stiftung Alfred-Wegener-Institut für Polar- und Meeresforschung, D-27498 Helgoland, Germany

Salinity as a key parameter in the larval biology of decapod crustaceans

Salinity is an ecological key factor in the life of estuarine and coastal plankton, and hence, also in the biology of meroplanktonic decapod crustacean larvae. Its influence has been noted in larval survival, development, morphology, the moulting cycle, growth, feeding, metabolism, energy partitioning, and behaviour. In this review, detrimental effects of unfavourable salinities are shown with examples from all these principal aspects of larval biology. Consequences of osmotic stress are discussed in relation to interacting effects of other environmental variables such as temperature or toxic pollutants, and in relation to intrinsic phenomena associated with development, the moulting cycle, and endocrine control systems. Special adaptations to variation in salinity are demonstrated in the reproductive strategies of estuarine species, in larval behaviour, and in the ontogeny of osmoregulatory structures and functions. Putative relationships between osmoregulatory patterns and the metabolic response to salinity are proposed.

Anker A.

Muséum National d'Histoire Naturelle, 55, rue de Buffon, 75005 Paris, France

Phylogeny of Alpheidae (Decapoda, Caridea) - preliminary results of a cladistic analysis of morphological characters, with particular emphasis on evolution of snapping claw

A cladistic analysis of Alpheidae, using the conventional PAUP methodology, produced a majority rule consensus tree which is the preliminary phylogenetic hypothesis of generic relationships within Alpheidae. The monophyly of the family is supported by several features, however, its affinities to other caridean families remain rather obscure. Relationships of two problematic genera, Yagerocaris and Pterocaris, are discussed in in light of the phylogenetic results. Evolution of robust, usually asymmetrical, first chelipeds is particularly complex. Notable modifications and polymorphism of chelae occur even within some " lower genera ". Plasticity of chelipeds is important in both lower and higher genera. As the monophyly of the clade uniting five genera all characterized by the snapping mechanism is reasonably supported (Synalpheus appearing as a sister group to the other four genera, including Alpheus), a unique origin of the snapping mechanism in Alpheidae should be assumed. However, Coutière (1899) believed that the snapping claw evolved independently in Alpheus and in Synalpheus.

Anker A.¹ and Jeng M.S.²

¹Muséum National d'Histoire Naturelle, 55, rue de Buffon, 75005 Paris, France ²Institute of Zoology, Academia Sinica, Taipei, Taiwan 115, R.O.C.

Cryptic species and colour patterns in Alpheidae (Decapoda, Caridea), with particular emphasis on goby-associated species of Alpheus.

Despite numerous taxonomic studies in the family Alpheidae all larger alpheid genera remain more or less problematical in this respect. Misidentifications or incomplete identifications are frequent. There are multiple reasons for this situation : presence of numerous cryptic / sibling species, absence of original type-material, superficial diagnoses, descriptions based on incomplete specimens, questionnable synonymies, rarity of specimens, insufficient or lacking field data (incl. colour patterns). Several common, " well defined " and " widely distributed " taxa actually represent species complexes, making the identifications of specimens very difficult or impossible. Numerous studies of ecological and behavioural aspects of associations between gobies and Alpheus spp. were not paralleled by taxonomic revisions of A. brevirostris species group, which contains the majority of goby-associated species. Detailed examinations of numerous UW photographs show that each species could be more easily identified by its distinctive colour pattern, however, most colour patterns can not yet be matched with descriptions based on morphology.

Anker A.¹ and Jeng M.S.²

¹Muséum National d'Histoire Naturelle, 55, rue de Buffon, 75005 Paris, France ²Institute of Zoology, Academia Sinica, Taipei, Taiwan 115, R.O.C.

Symbioses among the Alpheidae (Decapoda, Caridea)

The shrimp family Alpheidae is one of the largest decapod groups, and is particularly representative and diversified in shallow tropical waters. A considerable number of species is associated with other marine organisms. Alpheid shrimps are actually second in number and diversity of associations after the palaemonid subfamily Pontoniinae. All known symbiotic alpheids and their associates have been compiled in a huge reference table. The most interesting examples of these associations are presented in order of their ecological / behavioural characteristics. The hosts and associates of Alpheidae include species from ecologically and phylogenetically very different phyla, such as Porifera, Cnidaria, Annelida, Echiurida, Mollusca, Echinodermata, Urochordata, Crustacea and Pisces. This fact can be explained by the obviously high adaptative potential of Alpheidae, which may be partly due to their morphological variability and plasticity (e.g. first chelipeds, dactyli of third to fifth pereiopods) and to their strictly benthic life-style.

Asakura, A.

Zoology Department, Natural History Museum and Institute, Chiba, Japan

A taxonomic review of the hermit crab of Diogenes with the simple rostral process from the Japanese and adjacent waters (Decapoda: Anomura: Diogenidae)

The genus Diogenes is widely distributed in temperate and tropical waters of the world. The genus is divided into two groups. The species of Group I (sensu Rahayu and Forest) are those with well developed antennas, in which the antennal peduncles overreach the ocular peduncles; the species of Group II have only poorly developed antennas with the antennal peduncles shorter than the ocular peduncles. In this presentation, I review the species with the simple rostral process in the Group I from the Japanese and adjacent waters. These include D. costatus, D. dorotheae, D. edwardsii, D. goniochirus, D. guttatus, D. nitidimanus, D. penicillatus, D. rectimanus, D. spinifrons, and some undescribed species.

Auel, H.

Marine Zoology (FB 2), University of Bremen, Bremen, Germany

Trophodynamics and ecological role of the Arctic pelagic amphipod Themisto libellula.

Hyperiid amphipods of the genus Themisto play a key role in pelagic ecosystems. They prey on mesozooplankton and are major food items for higher trophic levels. The abundance, biomass, population structure, respiration and ingestion rates of the Arctic Themisto libellula were studied in the marginal ice zone of Fram Strait between Greenland and Svalbard. Abundance of T. libellula ranged from 0.02 to 0.05 ind. m-3. Juveniles of 10 to 20 mm total body length dominated throughout the investigation area. Males reached sexual maturity at a body length of >21 mm, presumably in their third year. Ingestion rates measured 0.019±0.015 d^–1 and 0.019±0.006 d^–1 according to feeding experiments and an energy budget approach based on respiration rates, respectively. The predation impact was low when compared to the mesozooplankton standing stock. Nevertheless, T. libellula may consume a substantial portion of zooplankton secondary production, since P/B ratios are very low under Arctic conditions.

Auel, H.¹ and Werner, I.²

¹Marine Zoology (FB 2), University of Bremen, Bremen, Germany ²Institute for Polar Ecology, University of Kiel, Kiel, Germany

Amphipods beneath the Arctic pack ice - adaptations to a sympagic versus a pelagic life style

The feeding behaviour and energetic demands of carnivorous Arctic amphipods were investigated off Greenland. Studies included the sympagic Gammarus wilkitzkii and the pelagic Themisto libellula occurring beneath the pack-ice. Respiration measurements revealed energetic demands of 1.1±0.4% of body carbon per day for G. wilkitzkii and 1.9±0.6% d^–1 for T. libellula. Feeding experiments with calanoid copepods revealed similar daily rations of 1.9±1.5% d^–1 for T. libellula. In contrast, ingestion by G. wilkitzkii was substantially higher (8.0±5.5% d^–1). These differences in the two amphipods may reflect adaptations to deviating life-styles in the same habitat. T. libellula is an actively swimming pelagic predator, whereas G. wilkitzkii usually stays attached to the ice saving energy by a reduced metabolism. However, it is able to react quickly when prey becomes available. This may be an advantageous strategy in the extreme environment of the Arctic pack-ice where utilising scarce and patchily distributed food sources is essential.

Austin, C.M. and Ryan, S.G.

School of Ecology and Environment, Deakin University, Warrnambool, Australia

Allozyme evidence for a new species of freshwater crayfish of the genus Cherax Erichson (Decapoda : Parastacidae) from the south west of Western Australia and the rapid extinction of the marron (Cherax tenuimanus)

The marron, Cherax tenuimanus (Smith), is one of the most easily recognisable members of the freshwater crayfish genus Cherax. Genetic studies indicate the species contains two genetically distinct forms. One of these forms is widespread and exploited via aquaculture and the other is restricted to single river system, the Margaret River. This paper present allozyme data collected from marron sampled from the Margaret River over a 19 year period which documents the introduction of the widespread form into this river and the subsequent reproductive interactions between the two forms of marron. These data indicate minimal interbreeding between the two form of marron and so justify their recognition as distinct species. An additional outcome of this study is that the Margaret River marron (C. tenuimanus) has been rapidly displaced by the introduced marron (C. sp. nov.). Consequently, urgent conservation measures are required to protect C. tenuimanus and prevent its possible extinction.

Bagnall, R.A. and Frohlich, D.R.

Department of Biology, University of St. Thomas, Houston, TX, USA

Nucleotide sequence and inferred secondary structure of internal transcribed spacer I (rDNA) of Americamysis bahia (Molenock, 1969)

We report the sequence of internal transcribed spacer 1 (rDNA) for Americamysis bahia and propose the first secondary structure for a Crustacean ITS1. Small variations in proposed secondary structures are compared between a Florida population and a Texas Gulf coast population.

Bamber, R.N.¹ and Seaby, Richard M.H.²

¹The Natural History Museum, Cromwell Road, London SW7 5BD, UK ²Pisces Conservation Ltd, IRC House, The Square, Pennington, Hampshire SO41 8GN, UK

The effects of power station entrainment passage on marine planktonic crustaceans

Experiments have been undertaken exposing larval common shrimp (Crangon crangon) and lobster (Homarus gammarus) and adult copepods (Acartia tonsa), to the key stresses of entrainment within power-station cooling-water systems. The apparatus has allowed the testing of mechanical, thermal, chlorine and pressure effects both alone and in combination, the range of the stressors spanning the standard conditions found within a coastal direct-cooled power station. Mechanical stresses affected only lobster larvae; pressure changes affected only the Acartia adults. Residual chlorine caused significant mortality of Acartia and shrimp larvae, but had no effect on lobster larvae even at 1 ppm. The temperature increment significantly affected all three species, with a synergistic influence on chlorine sensitivity in the shrimp larvae, but only unrealistically high temperatures affected the copepods. It is notable that, at least within the species tested, generalizations from the responses of one to those of another are not valid.

Bauer, R.T.

Department of Biology, University of Louisiana at Lafayette, USA

Extended male phase in a protandric simultaneous hermaphrodite, the caridean shrimp Lysmata wurdemanni.

All individuals first develop as a male-phase (MP). With increasing size MP's change to a female-phase (FP) that produces embryos but retains male reproductive function (simultaneous hermaphrodite). However, there are many MP's much larger than the minimum possible size of change to FP. One hypothesis tested was that MP's might benefit from a delayed change to FP if larger MP's are more successful at mating as males than FP's or smaller MP's. Success in insemination of pre-spawning FP's was compared between (1) FP's and small MP's (2) FP's and large MP's and (3) small and large MP's. No significant differences in mating success among sexual or size morphs were found. An alternative explanation is that FP's are capable of changing back to large MP's. However, no sex reversion occurred in groups of FP's reared under either optimal summer conditions (population structure hypothesis) or suboptimal winter conditions (non-breeding season hypothesis).

Bennet-Chambers, M.G.¹ and Knott, B.²

¹School of Biomedical Sciences, Curtin University of Technology, Bentley, WA 6845, Australia ²Department of Zoology, The University of Western Australia, Nedlands, WA 6008, Australia

Sublethal exposure and accumulation of cadmium in Cherax tenuimanus (Smith, 1912) (Decapoda: Parastacidae)

This study investigated the ability of the freshwater crayfish, Cherax tenuimanus (Smith, 1912) to accumulate cadmium in three tissues: hepatopancreas, gills and abdominal muscle. C. tenuimanus (marron) were exposed to 15ppb of cadmium over a 90 day period This was an exposure concentration the animal may encounter within the environment, particularly during periods of high agricultural runoff. Samples of three tissues (10 experimental; 5 controls) were taken at 30, 60 and 90 days, digested, and analysed for cadmium using AAS. There was a significant increase in the cadmium, stored within the hepatopancreas (p<0.0001) and absorbed by the gills (p<0.0001), of the exposed marron cadmium when compared to the controls. Accumulation of cadmium within these tissues also increased over time. However, the abdominal muscle of the exposed marron remained constant, after an initial increase at 30 days. This was possibly an effect of accumulation by the haemolymph surrounding the muscle, rather than regulation of cadmium uptake by the muscle.

Berge, J.

Dept. of Zoology, Tromsø Museum, University of Tromsø, 9037 Tromsø, Norway

Phylogenetical relationships of the amphipod family Stegocephalidae

The amphipod (Crustacea) family Stegocephalidae Dana, 1852 currently consists of 103 known species, most of which are restricted to the bathyal or abyssal zones. The family as a group has a cosmopolitan distribution, although there appears to be a bias towards the South Pacific and the North Atlantic basins (more than 50% of all known species are recorded in these two areas). Most stegocephalid species appear to be micropredators, but a few have also been collected in baited traps. Based upon a phylogenetical analysis of the family, which included approximately 91% of the total number of species, the family is divided into five subfamilies; Andaniexinae, Andaniopsinae, Bathystegocephalinae, Parandaniinae and Stegocephalinae. Morphological characteristics for these subfamilies are presented. At the generic level, the family is divided into 26 genera. At present, the Stegocephalidae is considered to be the sister taxon to the lysianassid group of families.

Berggren, Matz S.

Marine Ecology, University of Göteborg, Kristineberg Marine Research Station, SE 45034, Sweden

Shrimp associations and is it possible to use the problematic word ‘commensalism’?

Habitat choice among animals, marine as well as limnic and terrestrial, is mostly a combination of predator avoidance, food availability, living space, habitat accessibility and competition success. Both the benthic or semi-benthic shallow-water shrimps are rather omnivorous, making predator avoidance one of the major structuring forces the habitat preferences for the shrimps. This forces the shrimp to adapt to and utilize a special habitat, which will result in that the survival will be greater in the selected habitat than in any other habitat. This way of living cryptically on or in a host animal enhances different modifications of the shrimp towards the habitat in the evolutionary processes. Up till now it has normally been labelled ‘commensalism’, using a common defined word for a special type of symbiosis. From what we know today most of these associations are either totally unknown of their true association type or as some turn out to be a sort of ‘micro parasitism’. Therefore to start up a discussion in this subject, an alternative, more generalized term is proposed - 'colalism' - to label these unknown associations.

Berkenbusch, K.

National Institute of Water and Atmospheric Research, PO Box 11-115, Hamilton, New Zealand

Ecosystem engineering by a burrowing ghost shrimp: not a 'just so' story

The ecological concept of ecosystem engineering has recently been proposed to describe aspects of the relationship between organisms and their environment which are not direcly trophic or competitive. Since the initial reporting of the idea little work has been undertaken to formally assess potential ecosystem engineers in the marine environment, or to address questions which relate to the concept. Biological and ecological data for the burrowing ghost shrimp Callianassa filholi (Decapoda: Thalassinidea) allowed for a formal assessment of this species as an ecological engineer and showed that despite a low population density and the short durability of its burrow structures, Callianassa filholi affects a number of resource flows by its large lifetime per capita activity. Furthermore, the study of Callianassa filholi revealed the probability of interactions between antagonistic ecosystem engineers and the difficulty associated with separating the related concepts of keystone species and ecosystem engineering.

Bluhm, B.A., Brey, T., Klages, M. and Arntz, W.E.

Alfred-Wegener-Institute for Marine and Polar Research, Bremerhaven, Germany

Age determination in Antarctic Crustacea using the autofluorescent pigment lipofuscin

Determination of basic population parameters in long-lived Crustacea is hindered by the lack of appropriate methods for age determination. This study used the pigment lipofuscin as an age marker in the Antarctic decapod Notocrangon antarcticus and the amphipod Waldeckia obesa from the Weddell Sea. Resin brain sections were digitally recorded by confocal microscopy and images were subsequently analysed. A modal progression analysis of the lipofuscin concentration-frequency distribution revealed 8 and 5 regularly-spaced modes (assumed to reflect age classes) for N. antarcticus and W. obesa, respectively. No regular modes were obvious from the length frequency-distributions. The average yearly pigment accumulation rates were nearly linear. Lipofuscin-based estimates of growth parameters, P/B-ratios and mortality-rates indicate that both species are slow-growing, long-lived, and have low productivity compared to congeners from lower latitudes. Within the Antarctic benthos, however! P/B-ratios of the crustaceans are higher than those of most other taxa.

Bond-Buckup, G. and Castro, T.S.

Instituto Biociências, Departamento de Zoologia, PPG Biologia Animal, UFRGS, Sao Paulo, Brazil

The morphology of cardiac and pyloric foregut of Aegla platensis (Decapoda, Anomura, Aeglidae)

The aeglid crabs occur in streams, cavern rivers and lakes of subtropical and temperate regions in South America. The ossicle complex found in brachyura and anomura cardiac foreguts may reveal evolutionary connections between these two groups. The samples were collected from a Gravataí River tributary creek, in RS, the southernmost region in Brazil. They were separated by sex, dissected and prepared for an optical and electronic scanning microscopy analysis. It was found that the cardiac foregut consists of seven ossicles composing the gastric mills, six ossicles which provide its lateral support, but also of other seven structures such as valves and teeth. The pyloric foregut has nine ossicles, three valves, two ampullaes with many setose ridges that act as a food filter. Differences with other Anomura were found concerning the shape, size, calcification degree and lack or addition of one or more ossicles.

Boschi, Enrique E.

Instituto Nacional de Investigación y Desarrollo Pesquero and CONICET Casilla de Correo 175, 7600 Mar del Plata, Argentina

American anomuran decapods: diversity and distribution

The number of species of Anomuran in the continental shelves of Americas between the Arctic and Cabo de Hornos (Southern South America) at depths of no more than 300 m in the Atlantic and Pacific Oceans was estimate as 510 (Boschi 2000). Analyzing the distribution of species for zoogeographical provinces it is observed that in the tropical ones there exists the biggest biodiversity: caribbean with 205 species, includes the Caribbean Sea and part of Mexico Gulf and the Panamic one, which include the East Pacific with 165 species. The minor diversity is found in the provinces of high latitude: The Arctic with 9 species and the Magellanic with 22 species. This characteristic of the distribution is of clinal type, decreasing to temperate and cold regions, which is observed in the other groups of Decapoda. In the numerical importance the Anomura are the third group after Brachyura and Caridea.

Boudrias, M.A.

Marine and Environmental Studies, University of San Diego, USA

Thrust generation by the drag-based propulsive limbs of Eurythenes gryllus (Crustacea: Amphipoda).

Amphipods use a drag-based mode of paddle propulsion when swimming, with three pairs of abdominal pleopods providing the propulsive thrust. I measured the forces produced by pleopods from the large deep-sea lysianassid, Eurythenes gryllus, in the power and recovery stroke positions. Results suggest that the overall size and shape of the propulsive paddle, not the small-scale characteristics of the setae and setules, dominate force production. The net thrust (power force minus recovery drag) is statistically identical to the force yield of the power stroke suggesting a highly efficient recovery stroke with negligible effects on net thrust production. Paired pleopods generate less than twice the net thrust of two single pleopods. Direct measurements of force by paired pleopods on the power stroke yield drag coefficients that are significantly lower than flat plate values. This implies that total thrust must take the leakiness of pleopods into account for any calculations of thrust.

Boudrias, M.A.¹ and German, D.²

¹Marine & Environmental Studies, University of San Diego, USA. ²Department of Biology, California State University, Fullerton, USA

Burrowing behavior of the vernal pool ostracod Cypris pubera.

We observed several population-wide burrowing events in Cypris pubera during five successive wet-dry cycles of a vernal pool. In late spring, burrowing occurred only in a portion of the pool heated by direct sunlight. We performed laboratory experiments to examine the effect of elevated temperatures on population-wide burrowing. Our results indicate that temperature alone is not the determining factor. It does affect location in the vernal pool since ostracods spend 85% of their time on a surface and only 15% in the water column. Further observations of these burrowing events suggested that multiple seasonal factors (water level, temperature, and crowding) impacted burrowing. On two separate occasions C. pubera underwent torpor during the dry segment of the pool cycle, which was supported by the immediate presence of large sub-adults after rehydration. Thus the burrowing behavior may correlate with torpidity and allow Cypris pubera to dominate the vernal pool community more rapidly.

Boxshall, Geoff

The Natural History Museum, London SW7 5BD, UK

Arthropod evolution and the origin of the Crustacea: a history in three parts

Insights from developmental genetics continue to inform our understanding of relationships between major groups of Arthropods. Analysis of molecular sequence data continues to reinforce the concept of a close affinity between the Crustacea and the Hexapoda. How do our interpretations of morphology fit into the new order of things arthropodan? In this contribution I seek to distinguish between two key tagmatization processes: 1) cephalization by sequential incorporation of body segments into an anterior cephalon, and 2) cephalization by progressive specialization of ancestral multifunctional and tripartite limbs, to perform typically cephalic functions such as food capture and gathering sensory input. The dominant mode of evolutionary change resulting in such specialization is oligomerization (the trend towards reduction of body and limb segments and setation). However, simplistic assumptions that more parts equate to the plesiomorphic state and that fewer parts equate to the apomorphic state are unsupportable. Numerous examples of novel structures arising on limbs and of secondary multiplication of limb parts can be found in the Crustacea including the origin of epipodites and the formation of antennular and antennal flagellae.

Boyce, S.L., Spears, T. and Abele, L.G.

Department of Biological Science, Florida State University, Tallahassee, FL 32306-1100, USA

Molecular phylogeny of the Calappidae (Crustacea: Decapoda: Brachyura)

Crabs of the brachyuran family Calappidae sensu lato are a problematic group with respect to their phylogenetic relationships. Traditionally classified as four subfamilies (Calappinae, Hepatinae, Matutinae, and Orithyiinae) within a single family, Calappidae, recent physiological and larval evidence and morphologically based cladistic analyses have questioned this view. We have undertaken a molecular study to test hypotheses concerning calappid phylogeny. Approximately 650 base pairs of mt16S rDNA were obtained for representatives of eight genera (13 species) from all four subfamilies and for other families previously implicated in calappid phylogeny (e.g., Dorippidae, Leucosiidae, Portunidae, and Xanthidae). Parsimony and likelihood analyses do not support a monophyletic Calappidae. Instead, a monophyletic subfamily Calappinae is found that includes (Mursia + Platymera) and (Calappa + Cryptosoma) clades. Portunids appear as the sister group to the Calappinae with moderate bootstrap support. The Hepatinae (Hepatus + Osachila) are monophyletic, but relationships among the other calappid subfamilies are equivocal pending additional data.

Bradford-Grieve, J.M.

National Institute of Water and Atmospheric Research, Wellington, New Zealand

Colonization of the pelagic realm by calanoid copepods

The evolution of calanoid copepods probably extends back into the mid Paleozoic. Environmental change from the Paleozoic through to the Tertiary is reviewed. Turbidity, water clarity, oxygen, and tectonically induced changes in the morphology of the oceans are probably all important drivers of calanoid evolution and their invasion of the pelagic realm. Current views of the phylogeny of the Calanoida are presented as well as a review of some recent work on metabolic potential, female genital system, and nervous system. It is hypothesized that ancestors of the Arietelloidea and Diaptomoidea invaded the water column in the Devonian at a similar time to the Ostracoda and that the ancestors of the Calanoidea - Clausocalanoidea, with their myelinated axons, arose in the Permian during the major deep ventilation of the ocean. Present day distributions of some Diaptomidae, Centropagidae, and Calanidae suggest that these families successfully came through the Jurassic/Cretaceous expansion of the oxygen minimum zone and the K-T event.

Brandt, Angelika

Zoological Institute and Zoological Museum, Martin Luther-King-Platz 3, 20146 Hamburg, Germany

Antarctic isopod deep-sea biogeography - the importance of the ANDEEP expeditions

The deeper waters of the Scotia and Weddell Seas are some of the least explored parts of the world’s oceans and we know almost nothing about isopods that inhabit them. By contrast, we know that the present-day benthic animals of the Antarctic continental shelf exhibit many striking and unusual features, including gigantism, longevity, an extraordinarily high degree of endemism, and absence of taxa which are abundant in similar environments elsewhere. Such attributes are believed to reflect the geographical and hydrographical isolation of the shelves and their special environmental characteristics. Periodic extensions of the ice sheet and deep-water production may have enhanced speciation from the continental shelf down into the deep sea of the world’s oceans. For a better understanding of Antarctic deep-sea biodiversity and biogeography ANDEEP [ANtarctic benthic DEEP-sea biodiversity (ANDEEP): colonization history and recent community patterns], an international project to investigate the deep-water biology of the Scotia and Weddell seas from F/S Polarstern are planned.

Brockerhoff, Annette M.

Department of Zoology, University of Canterbury, Private Bag 4800, Christchurch, New Zealand

Influence of sex ratio on oviposition phenology of two intertidal grapsid crabs

The mating strategies of two grapsid crabs were studied in the field and laboratory to determine factors that influence female receptivity. In both species each female is receptive for only a few days shortly before oviposition. In field cage experiments, isolated Hemigrapsus edwardsi females stayed receptive significantly longer (mean 5.0 d) than females kept together with males (3.2 d), suggesting that H. edwardsi females are able to control receptivity. Laboratory experiments with Hemigrapsus crenulatus gave similar results suggesting that female receptivity control also occurs in this species. When previously isolated receptive females were joined with a male, they usually laid eggs within 24 h after mating. Females that were continuously exposed to males in different sex ratios did not show significant differences in their duration of receptivity but in the total number of matings. Interestingly, in the laboratory females became receptive several weeks before those in the field, and they had a shorter duration of receptivity. These observations are critical for studies on sperm competition which is thought to be an important component of sexual selection.

Brösing, A., Richter, S. and Scholtz, G.

Comparative Zoology, Institute for Biology, Humboldt-University of Berlin, Berlin, Germany

The brachyuran foregut-ossicle system and its purpose for phylogenetic studies

The foregut ossicle system of 42 species of Brachyura was examined and the ossicle-terminology of the brachyuran foregut was revised, which includes 37 ossicles. All described ossicles were documented by drawings and photographs. For a first cladistic analysis, some 30 characters of the foregut-ossicles were analysed using the computer program NONA. 1. The suggested monophyly of the Podotremata is not confirmed. The Dromiacea (Guinot, 1977) (including Homolodromiidae, Dynomenidae and Dromiidae) is the sistergroup to the other brachyuran crabs. So it seems that the Podotremata is paraphyletic. 2. The Homolidae is the sistergroup to the Raninidae + Eubrachyura. This shows that also the Archeobrachyura (Guinot, 1977) (including Poupiniidae, Latreillidae, Homolidae, Cyclodorippidae, Cymonomidae and Raninidae) is not monophyletic. 3. The sistergroup-relationship between Palicidae (a family of the Heterotremata) and Thoracotremata indicates a paraphyletic Heterotremata. This sistergroup relationship has also been suggested by Schubart et al. (1998) based on molecular data from the 16S rRNA gene. The congruent results with different character sets provide a strong evidence for this relationship. 4. The Thoracotremata is monophyletic supported by a number of apomorphic characters.

Buckup, Ludwig and Grala, Márcia M.

Dep. de Zoologia, Inst. Biociências, Univ. Federal do Rio Grande do Sul, Porto Alegre, Brazil

The burrows of Parastacus defossus Faxon, 1898 (Crustacea, Parastacidae)

Parastacus defossus is a burrowing crayfish, living in clayey soils in South Brazil and Uruguay. A population from Mariana Pimentel Municipality, RS, Brazil (30 20´S 51 22´W) was studied. An area of 100 m² was delimited and divided into 100 quadrats. All entrances in each quadrat were graphed. The dispersion pattern of the openings was investigated. The expected frequencies of the Poisson distribution do not fit the observed frequencies, consequently the openings are not randomly dispersed. The negative binomial was a good fit to the data, permitting to conclude that the population is not randomly dispersed, showing an aggregated dispersion pattern. The possible motives for the aggregation are discussed. Changing of place and number of openings was observed and accompanied in 20 quadrats chosen lot by lot, from August 1998 to July 1999. The burrows are sealed during summer drought and new apertures are prepared during winter. Gypsum casts from the burrows were obtained and studied.

Bueno, A.A.P. and Bond-Buckup, G.

Instituto de Biociências, Departamento de Zoologia e PPG Biologia Animal, UFRGS, Sao Paulo, Brazil

Feeding habits of Aegla ligulata Bond-Buckup & Buckup (Decapoda, Anomura, Aeglidae)

The analysis of stomach contents of Aegla ligulata specimens from a tributary creek of the Tainhas River, RS, Brazil, allowed the study of its feeding habits. A total of 369 males and 336 females were caught from August 1999 to August 2000. Dietary analysis was based on four methods: 1)Visual estimate of stomach fullness immediately after its removal; 2)Frequency of occurrence; 3)Percentage point methods; 4)Index of relative importance (IRI), combining frequency of occurrence (FO), percentage of total biomass and percentage of total numbers consumed. The bulk of the stomach contents comprised plant remains, algae, sand, dipteran larvae, nymphs of Ephemeroptera and Plecoptera, Trichoptera, Coleoptera. Stomach fullness was not sex related. Significant differences were revealed in relative proportions of prey items between males and females. The investigation showed that Aegla ligulata is omnivorous, feeding on benthic animals and plants.

Bueno, S.L.S.¹, Rocha, S.S.¹, Arantes, I.C.^{1, 2}, Kiyohara, F.¹, Silva, H.L.M.¹, Mossolin, E.C.¹, Melo, G.A.S.³, Magalhães, C.⁴ and Bond-Buckup, G.⁵

¹Department of Zoology, Institute of Biosciences, University of São Paulo, São Paulo, SP, Brazil ²University Brás Cubas, São Paulo, SP, Brazil ³Museum of Zoology, University of São Paulo, São Paulo, SP, Brazil ⁴National Research Institute of the Amazonia (INPA), Manaus, AM, Brazil ⁵Department of Zoology, Institute of Biosciences, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil

Freshwater decapod diversity in the State of São Paulo, Brazil

The BIOTA-FAPESP Programme is a major State scientific effort that aims the study of the biodiversity in the State of São Paulo, Brazil. As part of this programme, the present study focuses on freshwater decapods. This 4-year field survey started in mid-1999. Samples have been collected from several representative areas, mainly from environmentally protected sites and ecological sanctuaries. Decapods were collected with the aid of seines, traps or were manually removed from their shelters. So far, results from field collections, augmented by additional data of deposited specimens from museums, include trichodactylid crabs, aeglid anomurans, caridean shrimps and cambarid crayfish, totaling 31 species within 9 genera. Data are being used for evaluating endemism, for extending the knowledge on geographic distribution, for the recognition of established populations of exotic species and to associate vanished decapod populations from some areas as a result of environmental destruction carried out by man.

Calazans, D.

Departamento de Oceanografia - FURG Cx. Postal 474, Rio Grande, CEP 96.201-900, Brazil

Seasonal larval composition and abundance of shrimps in the surrounding area of the Patos Lagoon mouth

Larval phases of seven species of shrimps were found in the surrounding area of the Patos Lagoon mouth. Zooplankton and hydrographic samples in four seasonal cruises were undertaken between November 1982 and August 1983 in the coastal marine area around the Patos lagoon mouth. Seasonal species composition and their abundance were compared showing variations according to the season. Artemesia longinaris and Pleoticus muelleri were well represented throughout the year; Acetes americanus was present only during summer; Sicyonia typica only during autumn; Lucifer faxoni during summer and autumn; Peisos petrunkevitchi during autumn and winter and Farfantepenaeus paulensis during spring and summer.

Calazans, D. and Fernandes, F.P.A.

Departamento de Oceanografia, FURG Cx. Postal 474, Rio Grande, CEP 96.201-900, Brazil

Seasonal occurrence and abundance of brachyuran megalopa in the estuarine region of Patos Lagoon, Brazil (32 5'S 52 5'W)

Recruitment of brachyuran megalops was studied in the estuarine region of the Patos Lagoon where zooplankton samples with a conical 330(m mesh net were taken biweekly, in three positions near to the mouth of the lagoon and the coastal marine surrounding area. A total of 1.636 megalops were collected. During the summer Callinectec sapidus megalops were the most abundant with 46% of megalops caught( during autumn the most abundant was Chasmagnathus granulata with 26% of megalops collected and during spring Pinnixa sp. was the most abundant with 46% of megalops. During winter none megalops was collected. In the autumn were present 6 species Cystograpsus angulatus, C. affinis, C. altimanus, Pinnixa sp., Chasmagnathus granulata and Hepatus pudibundus. Abundance to all species shows to be sporadical like Callinectes sapidus were more than 90% of megalops were catch in one day only.

Castro, P.

Biological Sciences Department, California State Polytechnic University, Pomona, California, USA

Symbiosis, To Be or Not To Be

The participants of the symposium on the biology of decapod crustacean symbioses will review some recent developments on the biology of some of the symbiotic associations among decapods. Instances of symbiosis, close associations between two different species, are common among decapods. In fact, several families and subfamilies consist exclusively of symbiotic species. Several terms have been used to describe the many variations of symbiotic associations: commensalism, mutualism, parasitism, and others. The presence or absence of "harm" or "benefit" among the associates have traditionally been used to define these categories. Not only these terms can be ambiguous and subjective but also little is known about the biology of most of these associations. What is symbiosis? What terms should be used to define the categories of symbiosis? Should these terms be used at all?

Chan, Siu-Ming

Dept. of Zoology, The Univeristy of Hong Kong, Pokfulam Road, Hong Kong

Evidence for multiple vitellogenin genes expressions by the hepatopancreas and ovary of the shrimp Metapenaeus ensis.

In Metapenaeus ensis, the peak of vitellogenesis occurs during the premolt stage. We identified a 170 kDa polypeptide as the major egg yolk protein in the ovary. The anti-170 kDa antibody detected the presence of vitellogenin (Vg) in the ovary and only weak signal was recorded in the hepatopancreas. By genomic PCR and Southern blot analysis, about 3-4 Vg genes were identified in the shrimp genome. These Vg genes are highly conserved and each carries two small introns within the 1.0 kb partial Vg gene. Within the same 5' region of the Vg gene, similar gene organization also occurs in the fresh water shrimp Macrobrachium rosenbergii and the gene organization is comparable to other invertebrate and vertebrates Vg genes. Northern blot analysis detected Vg transcripts abundantly in the hepatopancreas and slightly in ovary of mature females. RT-PCR of hepatopancreas and ovary RNA resulted in the subcloning of two highly homologous cDNAs. Because of the apparent high degree of similarity in amino acid sequence and gene organization for Vg of M. ensis and M. rosenbergii, the expression of Vg in M. rosenbergii was re-examined. Contrary to the previous report in M. rosenbergii, we provided evidence that both the ovary and the hepatopancreas express Vg in this species. The difference in relative level of Vg expression in the ovary of the marine and fresh water shrimp suggests the importance of Vg to the supply of nutrient for larval development. In summary, the shrimp Vg gene is encoded by multiple copy of genes and it is expressed in the hepatopancreas and ovary of the adult females in both the M. ensis and M. rosenbergii.

Chapelle, G.¹, Coleman, C.O.² and Gonzalez, E.³

¹Institut Royal des Sciences Naturelles de Belgique, Rue Vautier 29, B-1040 Bruxelles, Belgium ²Museum für Naturkunde, Humboldt-Universität, D-10099 Berlin, Germany ³Ira C. Darling Center, University of Maine, Walpole, Maine 04573, U.S.A

Revisiting the species flock of Amphipoda in Lake Titicaca

Until recently, the described amphipod fauna of the lake consisted of 11 species, all from the genus Hyalella. However, using the exceptional material sampled in 1937 by a British expedition, Crawford & Lincoln tentatively ascribed most of the 70000 specimens to 104 morphotypes. This study undertaken in the seventies was advertised in a 1993 workshop, giving us access to this outstanding collection only in 2000. A first look at the collection confirmed that the main habitus represented by the described species were connected by morphological gradients. Whether these morphotypes reflect isolated populations, hence separated species, remains to be checked through both morpholy and genetics. Another interest of this collection resides in that it was sampled prior to the introduction of fish known to prey heavily on amphipods, thus providing a providential base line to estimate their impact on this endemic fauna.

Chiba, S. and Goshima, S.

Department of Marine Biological Science, Hokkaido University, Hokkaido, Japan

The advantage of male protandrous pandalid shrimp in delaying sex-change

In protandrous species, the change from male to female generally considers that large male which delay the timing at sex-change is not adaptive to enhance reproductive success. This study examined the male reproductive success with body size and estimated the adaptive significance of large males of protandrous shrimp, Pandalus latirostris. Field observation showed that several males of P. latirostris compete for a female to fertilize egg during breeding season. Effects of male body size on the fertilization success and the male-male competition for mate were examined by laboratory experiment. Small males could adequately inseminate females as well as large male in absence of competitor condition. However, large males increased the probability of fertilization in the male-male competition. Therefore, the male reproductive success increases with body size and delaying sex-change is adaptive in this shrimp.

Chu, K.H.¹, Ho, H.Y.¹ and Chan,T.Y.²

¹Department of Biology, The Chinese University of Hong Kong, Hong Kong ²Institute of Marine Biology, National Taiwan Ocean University, Keelung, Taiwan

Molecular phylogeny of the mitten crabs, Eriocheir s. l. (Brachyura: Grapsidae)

Eriocheir was previously considered to comprise of four species (E. japonica, E. sinensis, E. recta, and E. leptognathus), but recent taxonomic revision has recognized five species and split them to three genera. The genus Eriocheir is restricted to three species (E. sinensis, E. japonica, and E. hepuensis) and two distinct genera are established for the other two species (Neoeriocheir leptognathus and Platyeriocheir formosa). Yet the proposal is still controversial among crustacean taxonomists. This study aims to elucidate the phylogeny of the species of Eriocheir s. l. based on DNA sequence analysis of mitochondrial 16S rRNA, cytochrome c oxidase I (COI), and the first internal transcribed spacer (ITS-1) of nuclear rRNA. The results show that the three Eriocheir s. s. species are closely related to each other. The 16S rDNA sequences of the sister taxa E. sinensis and E. hepuensis are identical and their COI nucleotide divergence is about 5%, indicating that they are products of recent radiation. N. leptognathus is the most distantly related taxon within the group, with 12-15% COI divergence to the other species. In general, our results support the distinction of the crab based on morphological features as in the recent revised taxonomy, although the small genetic divergence among the crabs suggests that the five species can be grouped into a single genus.

Clark, Paul F.¹ and Calazans, Danilo²

¹Department of Zoology, The Natural History Museum, London, England ²Departamento of Oceanografia, Fundaçáo Universidade of Rio Grande, Rio Grande, Brazil

A review of the decapod and euphausiid larval terms, stage and phase

The use of the decapod and euphausid larval terms phase and stage are reviewed and clarified. Only four phases are recognised and recommended: nauplius, zoea, megalop and adult. These are defined and are submitted for consideration as standard within the Decapoda and Euphausiacea. A number of larval terms in general use are regarded as redundant.

Clark, Paul F.¹, Ng, Peter², Cuesta, Jose A.³ and Schubart, Christoph⁴

¹Department of Zoology, The Natural History Museum, London, England ²Department of Biological Sciences, National University of Singapore, Singapore 119260 ³Department of Biology, University of Louisiana at Lafayette, Lafayette, USA ⁴Biologie 1, Universität Regensburg, Germany

An appraisal of the systematics of the family Ocypodidae sensu lato using zoeal, adult, and DNA evidence

The morphology of 39 first zoeal stages currently assigned to the Ocypodidae and Camptandriidae was analysed for a phylogenetic study. Macrophthalmus zoea I present a consistent suite of characters but the inclusion of three species within the genus may require revision. The assignment of Shenius to the Macrophthalminae has already been questioned. Larval, adult and DNA characters all now confirm the affinity of Shenius with Ilyoplax and Scopimera species. On zoeal, adult and DNA evidence the Heloeciinae appears to be a monotypic taxon separate from Ucides (now Ocypodinae) and other Ocypodidae sensu lato. However, although the larval evidence confirms Camptandriidae monophyly, Dotilla systematics remains uncertain. This genus may be intermediate between the Dotillinae, Ilyoplax and Scopimera, and the camptandriids, representing a distinct taxon. Finally, analysis of larval, adult and DNA data suggest that the subfamilies comprising the ocypodids all require revision to familial status as currently recognised for the Camptandriidae.

Cobo, V.J.

Department of Biology, University of Taubaté - UNITAU, São Paulo, Brazil and NEBECC - Group of Studies on Crustacean Biology, Ecology and Culture

Breeding period of the spider crab Mithraculus forceps (Majidae, Mithracinae) on Southern Brazilian Coast

The goal of this research was report the breeding period of the spider crab M, forceps, based on the monthly frequency distribution of ovigerous females. Monthly collections were carried out from January to December 2000. Ovigerous females were recorded in hole sampled months, representing no less than 50% of the adult females, with the main peak in September which represented 100% of the adult females. For the M. forceps was observed a continuous reproduction pattern, as frequently reported for another crabs of tropical and subtropical regions.

Cobo, V.J.

Department of Biology, University of Taubaté - UNITAU, São Paulo, Brazil and NEBECC - Group of Studies on Crustacean Biology, Ecology and Culture, Brazil

Breeding period of the arrow crab Stenorhynchus seticornis (Majidae, Inachinae) from Couves Island, Southern Brazilian Coast

The aim of this study was report the breeding period of the arrow crab S. seticornis, based on the monthly frequency distribution of ovigerous females. Monthly collections were accomplished from January to December 2000. Ovigerous females were recorded in all sampled months, representing no less than 50% of the adult females, with peaks in March and April, representing 90.3% and 96.9% of the adult females, respectively. For the arrow crab was observed a continuous reproduction pattern, as commonly founded to decapods of tropical and subtropical regions.

Cockcroft, A.C.

Marine and Coastal Management, Private Bag X2, Rogge Bay, Cape Town South Africa

The management of South African crustacean fisheries: past, present and future

Three commercial fisheries for crustaceans occur off South Africa. Two of these are trap-fisheries targeting individual rock lobster species, namely: Jasus lalandii, in shallow water (< 100 m) along the west coast and Palinurus gilchristi, in deep water (100 - 200 m) along the south coast. A multi-species crustacean trawl fishery operates off the east coast. Prior to the Marine Living Resources Act of 1998, which formally recognised existing subsistence and informal fisheries for the first time, management of crustacean resources focussed almost entirely on the commercial sector. The Act therefore provided the dual challenge of incorporating previously disadvantaged portions of the community into the structures of well-established fisheries and the formal management of subsistence components of these fisheries. This paper reviews the status of the important crustacean resources and highlights past, present and future management options for these important South African fisheries.

Coelho, Vânia R.

Senior Research Scientist, Columbia University, Biosphere 2 Center, P.O. Box 68, Oracle, AZ 85623, USA

Intraspecific behavior of two pair-bonding thalassinidean shrimp, Axianassa australis and Pomatogebia operculata.

The intraspecific behavior of two pair-bonding thalassinidean species, Axianassa australis and Pomatogebia operculata was investigated. A. australis inhabits burrows built in mud flats while P. operculata lives inside corals. Specimens of A. australis were collected with a yabby pump at Praia do Araçá, São Sebastião, SP, Brazil. P. operculata individuals were extracted from Mussismilia hartti corals collected in several dives at Nova Viçosa Reef, Abrolhos, BA, Brazil. Behavioral observations were conducted in aquaria. The recognition display of both species initiates with individuals repeatedly sliding its antennae over the antennae of the other. However, in P. operculata, this display continues with the specimens touching the telson of each other with their antennae. In A. australis no fights were observed between males and females even if the specimens were collected from different burrows, although strong agonistic behavior was recorded between individuals of the same sex. Fights were not recorded between P. operculata male-female pairs found in the same burrow, but an aggressive behavior was observed between specimens of opposite sex found in different burrows, as well as between two males. In both species fights eventually ended with the death of one of the individuals.

Coleman, C.O.¹, Chapelle, G.² and Gonzalez, E.³

¹Museum für Naturkunde, Humboldt-Universität, D-10099 Berlin, Germany ²Institut Royal des Sciences Naturelles de Belgique, Rue Vautier 29, B-1040 Bruxelles, Belgium ³Ira C. Darling Center, University of Maine, Walpole, Maine 04573, U.S.A.

Variability of hyallelid Amphipoda in Lake Titicaca

Like the well described adaptive radiation of amphipods in Lake Baikal, the Hyalellidae from Lake Titicaca exhibit another example of an amazing morphological diversity of intralacustric evolution. On the basis of the huge amphipod collection of Titicaca amphipods, stored at the Natural History Museum London, populations of selected species are compared. These populations are morphologically and morphometrically characterized. Specimens from a certain population are morphologically very similar to each other, but differ strongly from representatives of other populations collected from other parts of the lake. A comparable case of distinct populations is shown from an amphipod species from Lake Baikal. In some cases the differences were so striking that these populations will be described as new species.

Colpo, K.D. and Negreiros-Fransozo, M.L.

NEBECC (Group of Studies on Crustacean Biology, Ecology and Culture) Departamento de Zoologia, IBB, UNESP, Botucatu (SP), Brazil

Comparative analysis of the reproductive potential of U. vocator (Herbst, 1804) in three subtropical mangroves

The brachyuran crabs of the genus Uca, commonly known as fiddler crabs, are very abundant in the South American mangroves, living in burrows built in the sediment and feeding on its organic matter. The reproductive biology of U. vocator was investigated in three Brazilian mangroves: Itapanhaú (23 49'14"S, 46 09'14"W), Indaiá (23 24'51"S, 45 03'14"W) and Itamambuca (23 24'43"S, 45 00'73"W). The aspects analyzed were fecundity, sexual maturity and size of ovigerous females. The crabs were captured during low tide by two collectors for 15 minutes. Organic matter content of the sediment from each locality was determined. The morphometric measures of each crab were: carapace width (CW), cheliped propodus length (CPL) and abdomen width (AW). Organic matter amount and size of ovigerous crabs increase from Itapanhaú to Itamambuca, being intermediate in Indaiá. Uca vocator presented variation in the size of onset sexual maturity and fecundity index in function of food availability in each mangrove, evidencing the reproductive potential is closely related to nutritional resources of the habitat.

Coman, F.E.^{1, 2}, Connolly, R. M.² and Preston, N.P.¹

¹CSIRO Division of Marine Research, PO Box 120, Cleveland, 4163, Australia. ²School of Environmental and Applied Sciences, Gold Coast campus, GriffithUniversity, PMB 50, Gold Coast Mail Centre, Queensland, 9726, Australia

Zooplankton and epibenthic fauna in shrimp ponds: factors influencing assemblage dynamics

We examined the crustacean zooplankton and epibenthos in a commercial shrimp pond in subtropical Australia. Zooplankton numbers and biomass ranged from 111.7 ind. l^–1 (324 (g l^–1) to 8.3 ind. l^–1 (44.2 (g l^–1). A rapid decline in abundance, immediately after the pond was stocked with shrimp postlarvae, indicated that copepods were a significant source of food for the postlarvae. Subsequent peaks in zooplankton abundance were lower than during pre-stocking and principally due to barnacle nauplii. Sergestids (Acetes sibogae) and amphipods were the most abundant epibenthos. Total abundance peaked at 14 ind. m^–2 and the biomass at 0.8 g m^–2, too low a level contribute a significant source of nutrients for juvenile shrimp. Variation in physico-chemical characteristics of the pond did not appear to impact significantly in the abundance and composition of the zooplankton or epibenthos. Instead, recruitment and predation appear to be the dominant factors influencing the dynamics of these assemblages.

Conides, A.J.¹, Apostolopoulou, M.², Thessalou-Legaki, M.², Nikolaidou, A.² and Lumare, F.³

¹National Centre for Marine Research, Ag. Kosmas, Hellinikon, Athens 166 04, Greece ²Department of Biology, Laboratory of Zoology and Museum, University of Athens, Ilisia 157 71, Athens, Greece ³ Shrimpculture Research Unit, University of Lecce, via Monterroni, 73100 Lecce, Italy

Maturity and reproduction of the mudprawn Upogebia pusilla population in western Greece

The mudprawn, Upogebia pusilla, population in Western Greece is heavily exploited today by fishing for use as bait. The method of fishing (with water pumps) is disastrous for the population causing stress. Monthly samples are taken from the area since 1999 for an ongoing research project. The first egg-carrying females appear around mid January (January 12 for 1999, January 18 for 2000 and February 4 for 2001). The reproduction period lasts between January and September following a double peak mode. The last egg-carrying female is observed during mid-September (September 12 for 1999 and September 23 for 2000). Almost all females of Upogebia show an intermediate gonad maturity stage between mature gonad and spent gonad. These females have a half-empty ovary and carry eggs on their abdomen, indicating that they are capable to reproduce again later during the same period. Gonad-somatic Index fluctuation indicates two peaks in reproduction: during February and June.

Conides, A.J.¹, Lumare, F.², Papaconstantinou, C.¹, Scordella, G.² and Kapiris, K.¹

¹National Centre for Marine Research, Ag. Kosmas, Hellinikon, Athens 166 04, Greece ²Shrimpculture Research Unit, University of Lecce, via Monterroni, 73100 Lecce, Italy

Skewed sex ratios and reproduction in an intensively exploited shrimp Penaeus kerathurus population in western Greece

The shrimp Penaeus kerathurus is a native in the Mediterranean region and it is considered as a valuable commercial product. In Greece, the shrimp can be found in Amvrakikos Gulf (Western Greece) and it is heavily exploited as a single-species fishery. Monthly samples were taken between 1999 and 2000 (EU research project DG XIV-Fisheries/037/98). Monthly sex ratios (as males/females) were found fluctuating between 0.5 and 2.65. This indicated that males dominate the samples during most of the year. In addition, the males arrive first in the mating grounds. The females arrive approximately 20 days later. Reproduction occurs between April and September. The maturation stimulus is the rapid increase of temperature by 7.70 C during March. This is followed by the initiation of migration towards the coastal zone for mating and then by spawning. The reproduction occurs in a single peak mode during July as shown from GSI index (10-12%).

Conroy-Dalton, S. and Huys, R.

Department of Zoology, The Natural History Museum, Cromwell Road, London SW7 5BD, UK

Character transformation and polyphyly in the Ancorabolidae (Copepoda: Harpacticoida)

Representatives of the Ancorabolidae are among the most visually striking harpacticoid copepods, instantly recognisable by their ornate body morphology. Despite its long history, the validity of the family as a whole and the monophyletic status of the two sub-families (Ancorabolinae and Laophontodinae) have until now, never been properly addressed. Recent studies revealed novel, phylogenetically significant characters derived from the remarkable patterns displayed by sensory sensillae and the integumental processes with which they are associated. Assessment of the homology of these sensillar patterns provides a key to the relationships and phylogeny within the Ancorabolinae. Distinct lineages are revealed, and unequivocal evidence is provided for their independent evolution from unadorned ancestors. Phylogenetic analysis of the Ancorabolidae shows the taxon to be highly polyphyletic, comprising at least four distinct lineages. Mounting evidence indicates the roots of these lineages to lie within the heterogeneous family Cletodidae, where they represent specialised or terminal branches.

Cook, B.¹, Choy, S.² and Davie, J.³

¹Griffith University, Nathan, Queensland, Australia. ²Queensland Department of Natural Resources and Mines, Brisbane, Australia. ³University of Queensland, Gatton, Queensland, Australia

Potential ecological Impacts of translocating Redclaw Crayfish, Cherax quadricarinatus.

The direct and indirect ecological impacts of the redclaw crayfish, Cherax quadricarinatus, on other aquatic macroinvertebrates outside its natural range of distribution were examined. Direct ecological impacts to macroinvertebrate fauna were determined by examining the interspecific and intergeneric agonistic behaviour of redclaw, its competition for shelters, and community establishment potential. Indirect impacts to macroinvertebrates were assessed via substrate and macrophyte perturbations. Redclaw is dominant over the local crayfish (yabby), Cherax depressus, and the local prawn, Macrobrachium australiense. Subadult yabbies dominate subadult redclaw, however mature redclaw dominate over mature yabbies. Both subadult and mature redclaw dominate over the prawn. It is unlikely that substrate perturbations by translocated redclaw would result in impacts to local macroinvertebrates. However, redclaw may have the potential to impact on macrophytes and associated macroinvertebrate fauna if they establish at high densities. It has been postulated that redclaw cannot become established where long-finned eels, Anguilla reinhardtii, occur. It was observed that the presence of this predator reduces activity in subadult redclaw, but did not seem to have the same effect on mature adults. It is concluded that eels are unlikely to control the spread and establishment of redclaw crayfish.

Corgos, A., Freire, J., Bernárdez, C., Fernández, L. and Verísimo, P.

Departamento de Bioloxia Animal, Bioloxia Vexetal e Ecoloxia, Universidade da Coruña, Campus da Zapateira s/n, E-15071 A Coruña, Spain

Timing and seasonality of the onset of maturity, gonadal maturation and mating in the spider crab Maja squinado: Relationships with habitat use and social structure

Sexual maturity, maturation and mating were monitored in the spider crab Maja squinado (Decapoda, Majidae) in shallow water of the Ría de A Coruña (Galicia, NW Spain) from 1997 to 1999. Juveniles inhabiting this area carried out a terminal moult to the morphometric adult phase from July to September, showing coordination among individuals, although females delayed one month the timing of this moult respect to males. Gonadal maturation in females started after the terminal moult, but males started to develop testicles several months before the terminal moult, after the pubertal moult to adolescent juveniles. During approx. 2 months after the onset of maturity, postpubertal adults remained in shallow waters, and after that they started a migration to deep waters. The reproductive status and body condition (hepatopancreas and leg muscle dry weights) were monitored for postpubertal adults along the migratory path to deep waters from September to December. Mating took place in deep habitats. Juveniles inhabited shallow (< 10 m) sandy bottoms and constituted aggregations that remained stable during long periods. After the terminal moult, postpubertal adults dispersed along the shallow habitat breaking down the aggregative structure and moved towards the deeper areas near the channel of the embayment.

Cox, Serena

School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand

Feeding behaviour of larval Jasus edwardsii.

Spiny lobsters form the basis of major fisheries in tropical to temperate areas of the major oceans of the world. The commercial interest in the aquaculture of members of this family is growing rapidly and is now facing some major constraints on further expansion. Overcoming these constraints will require a much more thorough understanding of the feeding behaviour and dietary requirements of the larvae stages than currently exists. The feeding behaviour, mouthparts and sensory structures of early stage Jasus edwardsii larvae has been investigated and described. Capture, manipulation and ingestion of prey items remained constant throughout stages 1-4, however the sensory structures became more developed with larval maturity. Mouthparts were also morphologically similar for each stage and processing ability was not significantly different. These results have significant implications for developing artificial diets for use in larval culture and incorporating desirable prey characteristics into the diet.

Crandall, K.A., Perez-Losada, M. and Carlson, M.

Department of Zoology and Monte L. Bean Museum, Brigham Young University, Provo, UT, USA

Phylogenetics and biogeography of the Southern Hemisphere freshwater crayfishes

Over 530 species of freshwater crayfishes are known to naturally inhabit areas of all continents except mainland Africa. Crayfishes are an interesting and imperative group to study because of the unusual distribution of species diversity (with two centers: southeast U.S. and Victoria, Australia), the ecological importance of crayfishes to freshwater ecosystems, and the fact that more than half of the known species of crayfish are considered threatened or endangered. Here we investigate the relationships among the genera within the Southern Hemisphere family Parastacidae. This family contains 14 genera distributed in Australia, New Zealand, Madagascar, and southern South America. Our study uses all the genera of the freshwater crayfishes as well as marine lobster outgroups and crayfishes from other families to provide an estimate of the evolutionary relationships among genera. Our estimates are based on nucleotide sequence data from both mitochondrial DNA (12S and 16S) and nuclear genes (18S and 28S), totaling ~6000 nucleotides of data. The resulting phylogeny is then used to test hypotheses of biogeography, morphological evolution, and conservation biology.

Cryer, M.

National Institute of Water & Atmospheric Research, Auckland, New Zealand

Developing a visual census technique for deep-water crustacean stock assessments

New Zealand scampi, Metanephrops challengeri, supports a 1000 t fishery. Stock assessment has been hampered by variable burrowing and emergence behaviour; research and commercial trawl catch rates are probably poor indices of abundance. Photographic surveying of burrows is being developed, based on a new deep-water digital camera. In a stratified survey of New Zealand's Bay of Plenty, 200-600 m depth, in February 2000, we estimated the average density of scampi burrow openings at about 0.10 m^–2 (12%). This means about 268 million burrow openings, only about one-third of the comparable estimate for a 1998 survey. The average density of visible scampi was 0.008 m^–2 (( 20%), about one-half of the estimate in 1998. The reasons for the differences between 1998 and 2000 surveys are unclear, but may be partly related to counting protocols. We are currently refining our protocols to provide for rigorous estimates of biomass using photography.

Cryer, M.¹, Hartill, B.¹ and O'Shea, S.²

¹National Institute of Water & Atmospheric Research, Auckland, New Zealand ²National Institute of Water & Atmospheric Research, Wellington, New Zealand

Effects of trawling on deep-water soft-sediment benthic communities

New Zealand scampi, Metanephrops challengeri, supports a 1000 t trawl fishery whose environmental effects are poorly understood. We combined data from the invertebrate bycatch of trawling with high-resolution tow-by-tow information on fishing effort since the start of the fishery. A suite of multivariate statistical analyses (linear modelling at community metric level, partial correlation at a species level, clustering at a station level, and ordination using nMDS and (partial) canonical correspondence analysis) showed that the composition of benthic assemblages vulnerable to trawling was predictable given a station's depth and fishing history. After excluding the effects of other variables, indices of fishing pressure explained 16-22% of variation in benthic community structure. Diversity increased with increasing depth but decreased with increasing fishing pressure. This work, undertaken at the scale of the fishery, suggests that there may be substantive effects of trawling deep-water soft-sediment benthic communities that should be considered in precautionary management.

Cuesta, J.A.¹, Schubart, C.D.² and Felder, D.L.¹

¹Department of Biology, University of Louisiana at Lafayette, Lafayette, USA ²Biologie 1, Universität Regensburg, 93040 Regensburg, Germany

Larval morphology and preliminary molecular systematics for the family Pinnotheridae de Haan, 1833, as evidence for a revised classification

The family Pinnotheridae is presently recognized as a group of 305 species, partitioned into 5 subfamilies: Anomalifrontinae, Asthenognathinae, Pinnotherinae, Pinnothereliinae and Xenophthalminae. Larval morphology is known for 53 species. In the present study, the zoeal and/or megalopal characters of these 53 species were compared to character states of larvae from possibly related groups among the Grapsoidea and Ocypodoidea. Pinnotherinae and Pinnotheriliinae share mouthpart setation patterns (close to Ocypodinae), but clearly differ in morphology of the antennae and telson. This supports recognition of separate familial status for each one, both of which are close to Ocypodidae. Differences in mouthpart setation, antennal development, and telson types distinguish larvae of Asthenognathus and Tritodynamia. These larval features suggest a close relationship of both genera with Varunidae (Grapsoidea), yet with clear differences between them that also support separate familial assignment. We suggest placement of Asthenognathus in Varunidae and establishment of a new family for Tritodynamia.

Cui, Z.X., Xiang, J.H. and Zhou, L.H.

The Experimental Marine Biology Laboratory, Institute of Oceanology, Chinese Academy of Sciences, Nanhai Road 7,Qingdao 266071, P. R. China

Triploidy induction with chemical shocks to Eriocheir sinensis.

Chemical treatment was employed to induce triploidy in Eriocheir sisnensis. The highest induction rate was 58.18%, with 6-DMAP(300 µmol/L) as inducer, 6 hour after ovulation, and the treatment time of 120 min; while with PA chemical as inducer, 5 hour after ovulation, and the treatment time of 240 min, the highest induction rate was 75.10%. In the chemical treatment experiments of PA chemical, 6-DMAP, CB, the highest induction rates were 77.51%, 51.70% and 49.10% respectively. In the treatment of pregnant crab with PA chemical, the pregnant crabs were normal after 4 hours' soaking, and even could recover after 10 hours soaking. The results showed that the highest induction rate was 73.14% during gastrula; 85.29% during zoea. Most seedlings died before megalopae owing to unsatisfactory culturing condition. For those did survive, 50.00% triploids were found during juvenile stage. In this study, a highly effective, cheap and safe inducer PA chemical (has been applied patent) was first used and triploid juvenile crabs were obtained for the first time.

Cunha, M.R.¹ and Sorbe, J.C.²

¹Centro das Zonas Costeiras e do Mar, Departamento de Biologia, Universidade de Aveiro, 3810-193 Aveiro, Portugal ²Laboratoire d’Océanographie Biologique, UMR 5805 (CNRS-UB1), 2, rue du Prof. Jolyet, 33120 Arcachon, France

A new collection of Crustacea from Lucky Strike: some notes on their ecology and spatial distribution within the hydrothermal vent field

The Lucky Strike hydrothermal vent field (Mid-Atlantic Ridge, 37º18'N, 32º16'W) and its surroundings were studied in August 2000, during the TTR-10 Cruise (Training Through Research - UNESCO/OIC), using a TV-assisted grab, a dredge and a gravity core (24, 8 and 1 samples, respectively). The macroinvertebrates were picked from the surface of the rocks and sorted from sieved sediments. Crustaceans occurred in 18 grab samples and accounted for about half of the identified taxa. One of the most interesting aspects of the collection is the high number of peracaridan species that are seldom collected during submersible dives and are also difficult to see and identify in video footages. The 667 specimens in the collection were ascribed to 41 different species (Cirripeda: 1; Amphipoda: 14, Isopoda: 13; Tanaidacea: 10; Decapoda: 3), including three probably new isopod species. Despite the high heterogeneity of the samples, a multivariate analysis (presence/absence data) identified two main clusters that can be related to the environmental gradient associated with the hydrothermal activity and geological settings within the vent field.

Dahms, H.-U.

Universität Oldenburg, FB 7, AG Zoosystematik und Morphologie, D-26111 Oldenburg, F.R.Germany

Burrowing crustacean nauplii: biology, ecology and evolution

Among Crustacean nauplii there is only one group of harpacticoid nauplii belonging to Stenhelia and Pseudostenhelia of Stenheliidae (Copepoda, Harpacticoida) constructing dwelling-tubes which do only consist of one opening serving as entrance and exit at the same time. They are skillful in lateral crawling locomotion, which they perform while stalking with the endopods of their second antennae. As for the correlation of a foreshortened body, lateral locomotion and refuge-seeking in a dwelling tube we hypothesize the following functional explanation: in order to reach or leave a narrow dwelling tube the fastest way, it is most suitable to enter and leave the tube sideways - in case backward locomotion is not possible. This way the evolution of lateral locomotion appears as a consequence of dwelling-tube construction.

Dahms, H.-U.

Universität Oldenburg, FB 7, AG Zoosystematik und Morphologie, D-26111 Oldenburg, F.R.Germany

The phylogenetic significance of the crustacean nauplius

Extant taxa like the Cephalocarida, Branchiopoda, Ostracoda, Mystacocarida, Copepoda, Cirripedia, Ascothoracida, Facetotecta, Euphausiacea and Penaeidea hatch from an egg as a free-living nauplius larva. Other crustaceans show an embryonic phase of development suggestive of a naupliar organization. The crustacean nauplius, as an organizational complex and phylotypic stage, is characterized by a remarkably conserved morphology. Besides structural and meristic differences, embryonic and postembryonic stages offer another set of characters, namely allometric differences and heterochrony for the reconstruction of phylogenetic relationships. From these character changes during ontogeny a gradient can be traced. Preadult characters suggestive of former character states, or that recapitulate those expressed in the course of ontogeny, are particularly valuable for the evaluation of phylogenetic character polarity. This morphology involving part of the genome of a group of organisms whose adults display remarkable adaptive radiation, has persisted with relatively minor modifications since Cambrian times.

Daniels, S.R., Stewart, B., Matthee, C., Cunningham, M. and Gouws, G.

Zoology Department, University of Stellenbosch, Private Bag X1, Matieland, 7602, South Africa

Phylogeny and biogeography of southern African freshwater crab species (Decapoda: Potamonautidae: Potamonautes) based on partial sequences from 12 and 16S RNA mt DNA genes, allozymes and morphology

The phylogeny of the southern African freshwater crab fauna was investigated using multiple data sets to, firstly, test the subgeneric divisions proposed by Bott (1955), secondly, to examine the relationships between hybridizing species pairs, and thirdly, to test the usefulness of freshwater crabs as zoogeographic indicators. Partial sequences from the 12 and 16SrRNA mt DNA genes were sequenced and analysed to explore the relationships among species. Generally, these two genes recovered the same tree topologies. Analyses of allozyme and morphological data further corroborated the placement of species. Bott's subgeneric divisions are paraphyletic and do not hold true. Secondly, most hybridizing species pairs appear to be closely related, and, thirdly, freshwater crabs are suitable organisms to test hypotheses regarding biogeographic relationships. These results are discussed in terms of contemporary and historic factors that are likely to have sculpted the present day distribution of species.

Daniels, S.R.¹, Gouws, G.¹, Stewart, B.¹ and Coke, M.²

¹Zoology Department, University of Stellenbosch, Private Bag X1, Matieland, 7602, South Africa ²KwaZulu-Natal Nature Conservation Services, P.O. Box 13053, Cascades, 3202, South Africa

Phylogeographic evidence for introgressive hybridization between two freshwater crab species (Decapoda: Potamonautidae: Potamonautes): implications for conservation and evolutionary significant units

Molecular data derived from allozymes and the 16SrRNA mitochondrial DNA gene were used to examine the degree of introgressive hybridization between populations of two freshwater crab species. Allozyme data derived from 16 loci revealed that three well-defined groups exist, including two groups formed by each of the putative species and a third group comprised of hybridizing populations. Congruent patterns were obtained from the DNA sequence data. Divergence between the two parental species and hybrid populations was equally high. The evidence supports the presence of an ancient introgressive hybrid zone between the two taxa that appears to be on a unique evolutionary trajectory. It has been previously argued that hybrid taxa are evolutionary insignificant. In the present study we explore the validity of hybrid taxa in the light of contemporary conservation dogma and argue for their conservation.

Daniels, S.R.¹, Stewart, B.A.¹ and Cook, P.A.²

¹Zoology Department, University of Stellenbosch, Stellenbosch, South Africa ²Zoology Department, University of Cape Town, Cape Town, South Africa

A congruent patterns of genetic variation as revealed by allozymes and mtDNA sequence analysis confirm the existence of high levels of gene flow in a burrowing freshwater crab

Five populations of the burrowing freshwater crab, Potamonautes calcaratus representing a total of 100 specimens, were collected from the Kruger Nation Park, South Africa. The population genetic structure of this species was investigated using both nuclear genetic markers (allozymes), and direct sequencing of a 610 base pair fragment the cytochrome oxidase 1(CO 1) subunit of the mitochondrial DNA. Electrophoresis of 21 allozyme loci revealed that populations were genetically similar (I = 0.984), with moderate differentiation (F(ST) = 0.12). Sequence data for 20 individuals revealed the presence of nine haplotypes, the distribution of which showed no geographic structuring. A ?ST of 0.43 was obtained among populations while within populations a ?ST of 0.62 was evident. The nucleotide diversity (?) was low and ranged from 0.00 to 0.007. Sequence divergence amongst populations ranged from 0.49% to 1.47%. Both genetic markers revealed weak population structuring, supporting the conclusion that high levels of gene flow are occurring among populations. These results provide evidence that allozyme and sequencing data may be congruent and that these independent markers can detect similar patterns of genetic differentiation. Results are discussed in light of contemporary factors that have been likely in sculpting the genetic structure.

Dauby, P., Nyssen, F. and De Broyer C.

Laboratory of Carcinology, Royal Belgian Institute of Natural Sciences, rue Vautier 29, B - 1000-Brussels, Belgium

Amphipods as food sources for higher trophic levels in the Southern Ocean

With nearly 900 different taxa, among which about 75% endemics, amphipods form one of the richest animal group of the Southern Ocean. They have colonized most habitats and exhibit very diverse life styles and trophic types. They moreover show a large size spectrum, with numerous giant species. Despite their importance in terms of biodiversity, very few is known about the role of amphipods in Antarctic trophodynamics. Based on an exhaustive survey of literature (>300 references), we tried to delineate their importance as potential food for higher trophic levels. About 200 different predators were recorded: 33 invertebrates (from 12 orders), 108 fishes (19 families), 48 birds (11 families), and 10 mammals. Using this vast dataset (total amount of citations close to 1500), an attempt was made to build up a small model, distinguishing between benthic and pelagic species of both amphipods and predators.

Davie, P.J.F.¹ and Dawson, E.W.²

¹Queensland Museum, PO Box 3300, South Brisbane, Queensland, 4101, Australia ²Museum of New Zealand, Te Papa Tongarewa, P O Box 467, Wellington, New Zealand

New species and new records of Lithodidae (Crustacea: Anomura) from Australia

Lithodids or "King Crabs" are relatively rare in Australian waters. Only three species have been previously identified, and all from deep waters (120 to 865 m) off the southeastern coast (Lithodes murrayi Henderson, 1888, Lithodes longispina Sakai, 1971, and Neolithodes brodiei Dawson & Yaldwyn, 1970). Apparently only L. murrayi Henderson, 1888, is moderately common, and none are fished commercially. Recent collections from tropical Australia have revealed the presence of a number of new records and new species. Material from the Coral Sea off north Queensland includes: Paralomis dofleini Balss, 1911; and Neolithodes nipponensis Sakai, 1971. Collections from off northern and northwestern Australia include: Acantholithus hystrix (De Haan, 1849) from the Timor Sea; and three new species from the North West Shelf, including a new species of Paralomis, and two new species of Lithodes. The nine Australian species comprise, a) two southern species confined to the Tasman Sea and sub-Antartic waters; b) three eastern Australian species that appear to belong to a more widely distributed western Pacific fauna; c) one northern species also a member of the western Pacific fauna; and d) three species indigenous to northwestern Australia.

Davie, P.J.F.¹ and Ng, N.K.²

¹Queensland Museum, PO Box 3300, South Brisbane, Queensland, 4101, Australia ²Department of Biological Sciences, National University of Singapore, Kent Ridge, Singapore 119260, Republic of Singapore

A review of Acmaeopleura Stimpson, 1858 (Crustacea: Brachyura: Grapsidae) with description of a new genus

Acmaeopleura Stimpson is reviewed and restricted to two species: A. parvula Stimpson, 1858, and A. rotunda Rathbun, 1909. The other three species attributed to this genus, A. balssi Shen, 1932, A. depressa Sakai, 1965, and A. toriumii Takeda, 1971, were discovered to all have third maxillipeds, and anterior sternal plates, strongly modified for filter feeding. All three appear to live commensally in the burrows of thalassinidean shrimps. The new genus is most closely allied to Gaetice Gistel, 1835, and the relationships of these two genera to other grapsoid crabs is discussed.

De Broyer C.¹, Scailteur Y.¹, Chapelle G.¹, Jazdzewski K.² and Rauschert M.³

¹Laboratory of Carcinology, Royal Belgian Institute of Natural Sciences, Rue Vautier 29, B - 1000 Brussels, Belgium ²Laboratory of Polar Biology and Oceanobiology, Department of Invertebrate Zoology and Hydrobiology, University of Lodz, 12/16 Banacha St., 90-237 Lodz, Poland ³Alfred-Wegener-Institut für Polar- und Meeresforschung, Forschungsstelle Postdam. Present address: Bruno-H.-Bürgel-Allee 31, D - 15732 Eichwalde, Germany

Habitat diversity of gammaridean amphipods in the Antarctic

Gammaridean amphipods appear to be ubiquitous in the Antarctic neritic communities where about 500 species have been recorded. By comparing benthic and pelagic catch data, ecomorphological traits and some ethological aquarium observations, an attempt was made to document the characteristic habitats and the microhabitats of the most common species. Six major macrohabitats (endobenthic, epibenthic with three levels, hyperbenthic, benthopelagic, pelagic and cryopelagic) and several symbiotic and endobiotic microhabitats (sponges, ascidians, hydrozoans and gorgonians) have been distinguished. Epibenthic species form the bulk of the fauna and are distributed among several strata formed by living sessile macrozoobenthos. Endobenthic species appear the second group in number, dwelling in the first centimetres of the sediment. Hyperbenthic (suprabenthic) habitat remains poorly documented. Few gammaridean species can be characterised as benthopelagic or pelagic and cryopelagic species have only been rarely recorded. The heterogeneous multi-strata environment of the benthos could account for the high species richness of the group in the Antarctic.

De Broyer, C.¹, Dauby, P.¹, Duchesne, P.A.¹, Jazdzewski, K.², Chapelle, G.¹, Jamar C.¹ and Weyland F.¹

¹Laboratoire de Carcinologie, Institut Royal des Sciences Naturelles de Belgique, 29 rue Vautier, B -1000 Brussels, Belgium ²University of Lodz, Laboratory of Polar Biology and Oceanobiology, Department of Invertebrate Zoology and Hydrobiology, 12/16 Banacha St., 90-237 Lodz, Poland

Biodiversity of the Southern Ocean: The "Ant'Phipoda" project

To assess amphipod biodiversity in the Antarctic coastal and shelf ecosystem (ACSE) and to evaluate their role in the ACSE, the Ant’Phipoda project was initiated in the framework of the SCAR EASIZ programme. .1 A Biodiversity Reference Centre for Antarctic Amphipods is under development at the Royal Belgian Institute of Natural Sciences in Brussels, including comprehensive databases on taxonomy, distribution and bio-ecology of the Antarctic amphipods and extensive reference collections and documentation. 2. An international network of 13 specialists (the "Antarctic Amphipodologist Network", AAN) was set up to undertake the taxonomical revision of the Antarctic fauna of gammaridean and caprellidean amphipods and to synthesize their biogeographical and ecological traits. 3. The elaboration of conventional and electronic identification tools for Antarctic amphipods has been undertaken by the AAN. 4. Studies on amphipod faunal -, habitat - and trophic type diversity are being conducted in selected benthic communities of the ACSE (Admiralty Bay in King George Island and the eastern Weddell Sea) to assess the potential roles of the habitat heterogeneity and trophic diversity in species diversification.

Desantis, S., Labate, M., D'Onghia, G., Maiorano, P., Cirillo, F. and Labate, G.M.

Department of Zoology, University of Bari, Via E.Orabona, 4 - 70125 Bari - Italy

Emi-spermatophore and spermatophore sperm surface glycoproteins in giant red shrimp Aristaeomorpha foliacea.

The sperm surface is involved in intercellular process of fertilization, thus the glycoproteins of sperm plasma membrane seem to be of critical importance in the fertilizing ability. Since it is known that mating can occurs a few months before ovulation, the aim of this study is to investigate the sperm surface glycoproteins using a series of lectin and prelectin methods in hemi-spermatophore and spermatophore spermatozoa in order to determinate the glycoprotein pattern associated with sperm fertilizing ability.

Diele, K.

Centre for Tropical Marine Ecology (ZMT), Fahrenheitstr. 6, 28359 Bremen, Germany

Timing of reproduction and larval dispersion of the mangrove crab Ucides cordatus cordatus (Ocypodidae) in the Caeté Estuary, North Brazil

Mating activities of U. cordatus cordatus and the abundance of larvae in a tidal channel of the Caeté Estuary were monitored from 1997 to 1999. Reproduction occurred in the rainy season between December and June and followed a lunar rhythm. Synchronised mate-searching and mating events took place during four days after new moon, with a peak in January or February. Females spawned at the following new moon in the inundated mangrove forest within four days at high tide. Subsequent ebb currents transported the larvae to tidal channels, where up to 225000 ind