432 BUIvI^ETIN OF THE BUREAU OF FISHERIES. 



« 



Genus CALLINECTES Stimpson. 



CaUinfctes Stimpson. iS6o. p. 320. 



KEY TO THE SPECIES OV THE BEAUFORT REGION. 



a. Frontal teeth, including the inner orbitals, four sapidus 



aa. Frontal teeth, including the inner orbitals, six ornalus. 



Callinectes sapidus Rathbun. Blue crabs. PI. xxxv, fig. i. 



Lupa hojlala Say. 1817, p. 63. and iSiS, p. 443. 



Lu/>a dicantha De Kay, 1S44. p. 10. 



Callinccles hailalus Ordway. 1836. p. s6S; Coues. 1871. p. 130: Paulmier. 1905. p. 143. 



Cailintctes sapidus Rathbun, 1S96. p. 352; Verrill. 190S. p. 370: Sumner, loii. p. 672; Fowler. 1912. p. 128-130. 



Carapace, including lateral spines, two and a half times as wide as long, moderately convex, nearly 

 smootli except on inner br;mchial and cardiac regions where it is lightly tuberctilate; a tuberculate 

 transverse line from one lateral spine to the other and a shorter transverse line about halfway between 

 this and the frontal margin; frontal teeth, four, including the inner orbitals, triangular, acute, botli pairs 

 more or less distinctly bilobed; anterior eight anterolateral spines of subequal length, concave on both 

 margins and acuminate; lateral spines nearly straight, longer than the space occupied by the three pre- 

 ceding teeth; inner suborbital tooth prominent and acute. 



Chelipeds of male large and powerful, those of the female considerably smaller; meros with three 

 spines in front and one small one at the distal end behind ; carpus with one spine and one spiniform tuber- 

 cle on tlie external surface ; manus stamg, prominently ribbed and with a strong proximal spine ; fingers 

 strong, nearly straight and strongly toothed. 



Length of a male, 67 mm. ; width, 166 mm. 



Color, grajdsh or bluish green of varying shades and tints relieved by more or less brilliant red on 

 the spines of the carapace and the fingers. 



This crab, so abundant along the Atlantic coast from Cape Cod southward, is common enough in 

 the Beaufort region to be of some commercial importiince . Throughout the siunmer soft crabs are caught 

 for local consumption and occasionally a few are shipped away. At Morchead City the business of 

 shipping soft crabs is Ciuried on with regularity-, though most, if not the whole, of the supply is obtained 

 from Barkers Island and jwints still farther to the eastward. Hard crabs are not utilized to any marked 

 degree. Some years ago at one of the oyster canneries in Beaufort an effort was made to establish a 

 crab-canning industr)-, but it was found that crabs could not be obtained in suflicient niunbers at the 

 time they were wanted and the ventiu-e failed. With proper apparatus and perhaps some patience in 

 training the fishermen to use it there should be no difficulty in securing quite as many blue crabs in the 

 neighborhood of Beaufort as at any other point along the coast. At present fishing is done only with 

 hand nets in the marshes and creeks. 



The development and behavior of the blue crab are extremely interesting, but the study of its life 

 history, while of no little practical improtance, is a matter of much difficult^'. Young crabs and some of 

 the older ones may be observed with case in shallow water near the shore ; the older indiN-iduals, however, 

 prefer deeper water and can not well be watched. When a number are confined together in a limited 

 space they will fight to the death and the victors will devour the vanquislied without compimction. 

 To confine a sufficient number of crabs of various sizes and both sexes in separate compartments is 

 troublesome and so far has been an impossibility', except during the summer months. The following 

 brief account is based on the observations of several years, and while incomplete gives the most important 

 facts as far as they have been ascertained." It also indicates how much is still to be learned. 



Egg-bearing females begin to appear in the spring, become abimdant during tlie summer, and 

 diminish rapidly in numbers in the early fall. The eggs, when first laid, are of a light orange-yellow 

 color, but as they grow older they darken and finally become dark brown or a dirty gray. They are very 

 small and may number anywhere from i to 5.000,000. Collectively they form a mass which projects 

 far beyond the margins of the abdomen of the female and interferes considerably with her movements. 

 She carries them about until they hatch, when the little crabs, in the zoea stage, leave the mother and 

 float away in the water. 



a In this connection see Hay. Report, Bureau of Fisheries, for 1904. P- 397. and Binford, Johns Hopkins Circ. February, 1911; 

 also ChiUester, Biol. Bull, xxi, no. 4, p. 335-348, 19x1. 



