Recognition characters. — Carapace subhexag- 

 onal, length contained in width about 1.3 to 1.4 

 times, greatest width at fifth pair of anterolateral 

 teeth, quite convex ; carapace minutely granulate, 

 and lightly pubescent especially near anterior and 

 lateral regions. Five anterolateral teeth, first two 

 coalesced and separated by a shallow sinus, third 

 and fourth larger and directed forward, fifth 

 smaller and directed somewhat outward; each of 

 last two teeth with an oblique ridge extending 

 inward and backward. Front with small median 

 notch, each half only slightly sinuate, with whole 

 forming a much flattened curve extending from 

 eye to eye. 



Chelae barely unequal, smooth, dissimilar; car- 

 pus and merus with a shallow groove parallel to 

 distal margin, and usually a blunt internal spine; 

 major dactyl without large basal tooth, fingers of 

 minor chelae not spoon shaped. 



Resembles Eurypanopeus depressus. 

 Measurements. — Carapace: length, 17 mm.; 

 width, 23 mm. 



Variations. — Where the ranges of N. t. texana 

 and N. t. sayi overlap, specimens are often found 

 which share characters of both subspecies (Rath- 

 bun, 1930a, p. 370, in part) . 



Color. — Carapace a dark, slaty bluish green, 

 brown or buff, with dark reddish-brown speckles 

 on yellowish background, or bluish purple on gray 

 background, especially on anterior portion of 

 carapace and upper portion of chelae ; outer face 

 of chelae yellowish gray; fingers dark or black, 

 color extending extensively on palm, tips light. 

 Habitat.— -Most studies indicate greatest 

 abundance on mud bottoms, though the form oc- 

 curs in other situations as well, and in the Chesa- 

 peake area in a salinity range of 14.66 to 31.62 

 °/ 00 in a dry year. Low-tide mark to 15 fathoms. 

 Type localities. — New Haven, Conn., and Cape 

 Cod, Mass. 



Knoion range. — Miramichi Bay, Prince Ed- 

 ward Island and Cape Breton Island, New Bruns- 

 wick, Canada (Bousfield, 1956), to eastern 

 Florida. Introduced, Swansea, Wales (Nay lor, 

 1960). 



Remarks. — Rathbun's subspecies N. t. nigro- 

 digita is here regarded as conspecific with N. t. 

 texana on the basis of examination of a series of 

 specimens in the Charleston Museum. Rathbun 

 (1930a) reported the largest male on record as 

 27.2 mm. wide. 



Figube 173. — Xcopanope texana sayi (Smith). A, male 

 in dorsal view, walking legs not shown ; B, large chela 

 in frontal view ; 10 mm. indicated. 



Ovigerous females have been taken from April 

 in South Carolina (Lunz, 1937a) to October in 

 Chesapeake Bay. Cowles (1930) found young in- 

 dividuals during fall, winter, and spring in 

 Chesapeake Bay, and concluded that juveniles 

 reach maturity the first summer after hatching. 

 Ryan (1956) summarized the work of Hyman 

 (1925) on zoeal and megalops stages, and gave 

 some data on size at maturity. He concluded that 

 mature females ranged in width from 6.1 to 18.7 

 mm. 



Chamberlain (1957, 1961) discussed develop- 

 ment time and stages in detail. He found develop- 

 ment limited to four zoeal stages (sometimes pre- 

 ceded by a brief prezoeal stage) and one megalops 

 stage. Developmental time varied with tempera- 

 ture (14 days at 30° C, 27 at '21° C.) and with 

 food. Larvae matured most rapidly when fed 

 Artemia salina nauplii, did moderately well on 

 Artemia and algae, but did not transform at all 

 when fed pure algae. 



McDermott and Flower (1953) considered this 

 form to be the most abundant mud crab in Dela- 

 ware Bay, but within the area studied it was more 

 common on oyster beds than in littoral or low- 



MARINE DECAPOD CRUSTACEANS OF THE CAROLINAS 



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