WILLIAMS: CRABS OF THE GENUS CALLINECTES 



slopes of the prominent frontal teeth, but in 

 material from Louisiana there is a tendency to 

 development of the submesial frontals, and the 

 anterolateral teeth are generally more acute than 

 in Chesapeake Bay material. Specimens from 

 Veracruz, Mexico, in the AHF collection show 

 rather blunt frontal but acuminate anterolateral 

 teeth and rather prominent regions on the 

 carapace. Most specimens from southern Florida 

 to southern Brazil approach the "acutidens" 

 form, but throughout this vast region there is 

 much variation. 



The sharpest- and longest-spined forms with 

 most prominent development of rudimentary 

 submesial frontal teeth occur in the western 

 Caribbean Sea along the Guatemala-Panama 

 coast. These individuals also have regions on the 

 carapace more deeply and sharply sculptured than 

 in the "typical" form, sharp granulation on both 

 carapace and chelipeds, and cardiac and to some 

 extent mesobranchial regions exhibiting a crowd- 

 ing of granules at the apex leading to formation of 

 slight transverse ridges, but with the anterior 

 slopes of these regions lacking granules. While 

 some specimens from Puerto Rico approach those 

 from the western Caribbean in ornamentation, 

 there is a mixture of "typical" features in many 

 individuals, as elsewhere in the Antilles. Perhaps 

 the best illustration of mingling features is illus- 

 trated by three lots of specimens in the RMNH. In 

 23404 from Trinidad are two males. Both have 

 crowding of granules into a transverse ridge on 

 the cardiac lobes with largest granules behind and 

 fewer on the anterior slope, and a faint tendency to" 

 ridging of granules on the mesobranchial regions. 

 The smaller specimen has the more deeply sculp- 

 tured carapace, but rather blunt frontal, outer 

 orbital, and suborbital teeth, and rather short, 

 acute anterolateral teeth except for the last two 

 which are acuminate. The larger specimen has a 

 rather smooth carapace, but acuminate, long, and 

 outwardly turned outer orbital and suborbital 

 teeth, rather acute frontals with rudimentary 

 submesial teeth, and quite acuminate anterolat- 

 eral teeth throughout the length of the row. 

 Another male from Trinidad (17738) has a trans- 

 verse row of crowded granules on each cardiac lobe 

 with the anterior slope relatively smooth, and 

 mesobranchial regions with crowded granules but 

 no ridging. The frontal teeth are neither espe- 

 cially sharp nor sinuous mesially, and the an- 

 terolateral, outer orbital, and suborbital teeth, 

 like many "typical" specimens, are acuminate 



but not markedly so. Two females from Curacao 

 (11881) seem to be nearly "typical" in all re- 

 spects. One of them has granules crowded into a 

 poorly defined transverse ridge on each cardiac 

 lobe; however, there are granules on the anterior 

 slopes of these lobes. In sum, each of these speci- 

 mens shows different combinations of the 

 "sapidus"-"sapidus acutidens" complex. 



The paratype male "acutidens" from Rio de 

 Janeiro (USNM 19083) is not as acute spined as 

 Panamanian material and the outer orbitals are 

 rather blunt by "acutidens" standards. 



In rather scanty material available from south- 

 ern Brazil and Uruguay, though the "acutidens" 

 form predominates, teeth are not so sharp as in 

 Panama and the ridging of granules on the 

 carapace is suppressed to give a smoothed effect 

 reminiscent of that in North American specimens. 



The first gonopods of males, one of the most 

 reliable characters for separating species of 

 Callinectes, offer no help in separating "typical" 

 and "acutidens" forms of sapidus. This pair of 

 appendages shows individual variation on a basic 

 structural theme ( Figure 2 1 ) having more correla- 

 tion with age than with general body facies or 

 geographic region. It is apparent that movable 

 retrogressive spinules in the main row of spinules 

 increase in length with age, and that there is no 

 set arrangement except a tendency to an irregular 

 grouping of slender subterminal spinules more 

 erect than the proximal ones. The flared mem- 

 branous tip has an irregular quadrilateral or 

 elliptical shape. 



Abdominal segments of mature females vary in 

 shape, some (such as USNM 126789, Dominica) 

 having the distal edge of the sixth segment 

 broadened at its distal corners to an almost 

 rectilinear form, whereas in most this segment 

 tapers toward the telson. 



Gonopores of the females vary in width of 

 aperture and ornamentation of margins. The var- 

 iations shown in Figure 23b, c represent some 

 extremes, but there is no association of pattern 

 with geography, the only constant being the 

 elongate opening characteristic of species in 

 which gonopods of males are long. 



Distribution . — Occasionally Nova Scotia, 

 Maine, and northern Massachusetts to northern 

 Argentina, including Bermuda and the Antilles; 

 Oresund, Denmark; the Netherlands and adjacent 

 North Sea; southwest France (found twice); Golfo 

 di Genova; northern Adriatic; Aegean, western 



781 



