Blue crab - Callinectes sapidus
Diagnostic characters: Carapace more than twice as broad as long; 9 blunt to acuminate teeth (outer orbital
tooth and strong lateral spine included) on arched anterolateral margin; front (excluding inner orbital angles)
bearing 2 obtuse to acuminate, broadly triangular teeth with often sinuous inner margins longer
than outer margins. Much of convex dorsal surface smooth, but scattered and transverse lines of fine granules;
sculpture of regions near centre varying from low and smooth to rather sharply raised relief with crowded
granules; pincers strong, dissimilar, and ridged longitudinally; fifth legs flattened in formof paddles.Males with
T-shaped abdomen reaching level of thoracic sternite 4; slender first pleopods with membranous tip reaching
beyond suture between thoracic sternites 4 and 5; sinuously curved, overlapping proximally and
armed distally with a row of large and small retrogressive spinules (magnifying glass required). Colour: greyish,
bluish, or brownish green of varying shades and tints dorsally on carapace and chelipeds; spines may
have reddish tints, tubercles at articulations of legs orange, and legs varying blue and white with traces of red
or brownish green. Males with propodi of chelae blue on inner and white on outer surfaces, fingers blue on inner
and white on outer surfaces and tipped with red.Mature females with organge fingers on chelae tipped with
purple.Underparts off-white with tints of yellow and pink.Colour variations associated with sexual dimorphism
and molt cycle are known.
Size: Maximum width: 209 mm, exceptionally 227 mm.
Habitat, biology, and fisheries: A coastal crab inhabiting a variety of bottoms in fresh water, estuaries, and
shallow marine waters usually down to 35 m, occasionally 90mdepth. Hatching occurs in mouths of estuaries
and shallow marine waters, development of larvae progresses in the ocean, followed by migration of
megalopae and young crabs back into estuarinewaters to mature into adults.Feeds on a variety of prey including
oysters, clams, other bottom invertebrates, fishes, some vascular plant material and detritus, and carrion.
Of major interest to fisheries. Traditionally, however, the seat of this fishery is in Area 21 (mostly Chesapeake
Bay). In Area 31 from 1984 to 1998, 750 449 t of blue crab were caught (mean capture production was 50 029 t/year).Caught with pots, trotlines, bottom trawls, fyke nets, dip nets, scrapes, and dredges. Marketed fresh.
Distribution: Western Atlantic: Nova Scotia, Maine, and northern Massachusetts to Argentina, including Bermuda and the Antilles. Introduced in Europe (Denmark, Netherlands and adjacent North Sea, France, Golfo di Genova; northern Adriatic; Aegean, western Black, and eastern Mediterranean Seas. Introduced also in Japan. (found twice); now rather abundant in parts of northern and eastern Mediterranean Sea and also in Japan.