WILLIAMS: CRABS OF THE GENUS CALLINECTES 



Indo-Pacific Portunidae, but later left intact 

 (Stephenson, Williams, and Lance, 1968). 



In 1896 Rathbun recognized the following num- 

 bers of species: western Atlantic, six species and 

 one subspecies (Rathbun never treated the nomi- 

 nal subspecies as anything but a full species); 

 eastern Pacific, four species; eastern Atlantic off 

 Africa, one species and one subspecies. The list 

 was almost immediately altered (1897) by name 

 recombinations, elevation of subspecies, descrip- 

 tion of a new species, and extension of known 

 geographic ranges. This brought the numbers to: 

 western Atlantic, six species and one subspecies; 

 eastern Pacific, four species; eastern Atlantic off 

 Africa, four species. There the inventory rested 

 until 1921 when Rathbun revised the African 

 species, reducing them to three but noting a doubt- 

 ful subspecies reported from Europe (Bouvier, 

 1901) greatly resembling C. sapidus of the United 

 States. In 1930 Rathbun published the third of a 

 four-volume work that serves as the standard ref- 

 erence on American crabs. In this she reduced the 

 recognized species in the eastern Pacific by one. 

 Collaterally she treated fossil members of the 

 genus, describing three new species from the 

 Oligocene and Miocene of Middle America 

 (1919b), and two more species from similar ages in 

 North America (1935). One of these from the 

 Miocene (=?) of Virginia and Florida was consid- 

 ered identical with living C. sapidus. 



By 1930 the genus seemed stabilized, but Rath- 

 bun herself had introduced confusion in 1907 by 

 describing a juvenile Portunus from the South 

 Pacific as Callinectes alexandri. This error bore 

 fruit years later in helping to generate doubt con- 

 cerning validity of the genus (Stephenson and 

 Campbell, 1959). During the same year that 

 Rathbun's cancroid treatise appeared, Contreras 

 ( 1930) described two new species in a little known 

 paper, one from the Gulf of California and another 

 from the Gulf of Mexico. Capart (1951) and Monod 

 (1956) both supported Rathbun's analysis of West 

 African forms, and in shedding more light on the 

 introduction of C. sapidus into European waters 

 (first noticed in 1901) erased Rathbun's doubts 

 about a poorly documented subspecies from that 

 area. They also pointed out difficulties in identify- 

 ing some specimens. The introduction of C. 

 sapidus, documented by numerous authors, was 

 reviewed by Holthuis (1961, 1969). Following pe- 

 tition of Holthuis (1962), the International Com- 

 mission (1964), to avoid confusion in nomencla- 

 ture of such a well-known species, made Cal- 



linectes sapidus Rathbun the type species of the 

 genus and suppressed the long dormant Portunus 

 diacantha Latreille, 1825. Garth and Stephenson 

 (1966) confirmed Rathbun's interpretation of the 

 eastern Pacific Callinectes, and Williams (1966) 

 described a new species from the Carolinian Prov- 

 ince of North America. 



Such was the status of the species problem when 

 the present study was undertaken. Numerous au- 

 thors had expressed difficulty in making 

 identifications, especially of juvenile material. 

 Geographic limits for species seemed ill defined. 

 Few attempts to analyze large series systemati- 

 cally had been attempted, but results of work in 

 fisheries management indicated that populations 

 within species might be distinct. Mindful of this 

 and aware of series of specimens in museums, a 

 review of the group seemed profitable. Simultane- 

 ously, Taissoun (1969, 1972) began study of Cal- 

 linectes in Venezuela finding a form endemic to 

 Lake Maracaibo. It is likely that new approaches 

 such as ecological and larval studies may continue 

 to elucidate variation in the genus. 



CHARACTERS OF SYSTEMATIC 



VALUE 



The gross features of morphology having 

 greatest usefulness in distinguishing species of 

 Callinectes are (Figures 1, 2): viewing dorsally, 1) 

 the number, shape, and arrangement of frontal 

 teeth, 2) shape of the metagastric area, 3) shape 

 and curvature of the anterolateral teeth and the 

 lateral spine, 4) granulation of the dorsal surface; 

 viewing ventrally, shape of male and mature 

 female abdomen. Shape of the chelipeds is also 

 useful, as are the colors in fresh specimens. In 

 addition to gross features, male first pleopods 

 (Figures 18-21) are diagnostic, and shapes of 

 female gonopores (Figures 22-23) are aids to 

 identification. 



Body proportions. — Proportions of the body in 

 both sexes change with growth until a charac- 

 teristically male or female form develops. The 

 carapace of males becomes relatively broader than 

 that of females, with lateral spines accentuated; 

 in especially large individuals of some species the 

 metagastric region tends to be somewhat sunken 

 at its side and rear margins. Females have a dor- 

 sally tumid appearance, with the carapace more 

 uniformly inflated and granulated and relatively 

 not so broad nor with lateral spines so accentuated 



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