• Adult distribution patterns
• Adult morphology
• Adult reproductive behavior and fecundity
• Adult dietary scope and preferences
• Adult feeding behavior
• Age and growth
• Genetic stock structure/profile
• Egg case morphology, viability, and structure
• Juvenile feeding behavior
• Juvenile development, salinity tolerances, and ecology
• Larval development, metamorphosis, and settlement
• Larval salinity tolerance
• Larval feeding and swimming behavior
• Ecological consquences for local benthic invertebrates e.g., the striped hermit crab
• Predator-prey interactions with local fauna

Adult distribution

Rapa whelk distribution within Chesapeake Bay, USA was initially described by Harding and Mann (1999). The VIMS rapa whelk bounty program provides a tool to map the distribution of adult rapa whelks within the Chesapeake Bay and provides an estimate of the invasion progression within the Chesapeake. The regular contributions of rapa whelks to the bounty program by commercial fishermen allowed identification of three range expansions by rapa whelks in the Chesapeake Bay as described by Harding and Mann (2005). As the invasion continues, continued collections will be crucial.

Related publications include:

Harding and Mann, 1999.
Harding and Mann, 2005.

Adult morphology

The morphology, or shape, of the rapa whelk's shell may provide clues as to the habitat conditions in which the animal lived. Animals that live in places where they have abundant food, few predators, or low fishing pressure may achieve larger sizes than animals in habitats where food is limiting, predators are abundant, or fishing pressure is reduced.

Rebecca Green examined potential ecological causes and their influences on shell form among and between the Korean, Black Sea, and Chesapeake Bay populations of the invasive gastropod, Rapana venosa, in addition to between the Rapana species for her VIMS/SMS M.S. thesis project.

Adult reproductive behavior and fecundity

An understanding of adult rapa whelk reproductive behavior in Chesapeake Bay may provide clues to both breeding range and potential control strategies for this invader.

Erica Westcott investigated the reproductive biology of adult rapa whelks in the lower Chesapeake Bay as part of her VIMS/SMS M.S. thesis.

Catherine Ware investigated potential spatial and temporal limits on breeding and reproductive biology of Chesapeake rapa whelks as part of her VIMS/SMS M.S. thesis.

Related publications include:

Mann et al. 2006.
Harding et al. 2007

Adult feeding behavior

Given that rapa whelks are noted shellfish predators and have been credited with the destruction of shellfish stocks in other habitats that they have invaded, there is concern as to the impact that this predator will have on the endemic hard clam and oyster populations in the lower Chesapeake.

Dario Savini, a student from the University of Wales Bangor at Menai Bridge, examined feeding behavior of adult rapa whelks in our lab as part of his masters project.

Related publications include:

Savini et al. 2002.

Genetic stock structure/profile

Much as genetic tools are being used in modern times to identify individuals, these same tools offer the potential to characterize populations of organisms. In the case of rapa whelks, genetic tools may help us identify potential source populations of rapa whelks in relation to invasive populations.

Arminda Gensler examined the genetic profiles of rapa whelks from Chesapeake Bay, the Black Sea, and Korea waters as part of her VIMS/SMS M.S. thesis.

Juvenile feeding behavior

The feeding success of a small, recently settled rapa whelk is directly related to the animal's recruitment success. If the young snail does not find adequate food, it will not survive.

Peter Kingsley-Smith, a Ph.D. student from the University of Wales Bangor at Menai Bridge, examined the feeding behavior of juvenile rapa whelks in relation to local similarly sized gastropods.

Larval development, metamorphosis, and settlement

Descriptions of rapa whelk veliger morphology and development under culture conditions provide comparative tools for assessing gastropod veligers from plankton collections. Descriptions of larval growth rates as well as time to settlement and size at settlement provide valuable information for assessing the planktonic period of development.

Related publications include:

Harding, JM. 2006.

Larval salinity tolerance

The ability of a larvae to survive variations in environmental parameters such as salinity has a great deal to do with the potential of an invader to survive in a receptor region as well as potentially expand its range within a non-native habitat.

Bryn Jones, a student from the University of Wales Bangor at Menai Bridge, worked with us to examine the salinity tolerances of larval rapa whelks as part of his masters project.

Related publications include:

Mann, R. and J.M. Harding. 2000.
Mann, R. and J.M. Harding, 2003.

Predator - prey interactions with local fauna

Rapa whelks have a multi-stage life cycle. Habitat use and vulnerability to local predators changes ontogenetically. Field and laboratory projects investigating the role of rapa whelks as prey for local benthic predators are in progress.

Related publications include:

Harding, J.M. 2003.
Harding et al. 2007.