PERKINS: LARVAL STAGES OF DEEP SEA RED CRAB 



and Carcinoplax bear spines on the carapace, 

 while megalopa of Geryon do not. 



The exopodite of the antenna in zoeae of Ger- 

 yon quinquedens is about one-half the length of 

 the protopodite; in Gouoplax (Lebour, 1928) 

 the exopodite is about the same length as the 

 protopodite, and bears two short setae medially, 

 rather than terminally as in Geryon. On the 

 basis of the relative length of these two struc- 

 tures, Geryon would not align with Gorioplax in 

 Lebour's key to the zoeae. The configuration 

 and relative length of the antennal exopodite 

 and protopodite in Geryon are more like those 

 of Cancer (Poole, 1966), some portunids (Le- 

 bour, 1928; Roberts, 1969) and certain grapsids 

 (Diaz and Ewald, 1968). Boyden (1943) and 

 Leone (1951) discuss the serological relation- 

 ships of Geryon quinquedens to other members 

 of the Brachyura. Each found Geryon to be 

 closer to the Xanthidae than to other families 

 tested, with certain affinities noted to the Can- 

 cridae and Portunidae. However, neither of 

 these workers tested other members of the Go- 

 neplacidae against Geryon. The zoeae of Geryon 

 quinquedens are similar to most xanthid zoeae 

 (Lebour, 1928; Costlow and Bookhout, 1968) 

 in the number of zoeal stages, the spines on the 

 carapace, and the armature of the telson. How- 

 ever, there are differences in the latter two 

 characters within the Xanthidae alone (Costlow 

 and Bookhout, 1966). The structure of the 

 zoeal antennae of Geryon is decidedly different 

 from the antennae of xanthid zoeae; in xanthid 

 zoeae the exopodite of the antenna is very short 

 in relation to the length of protopodite. 



The number of terminal setae on the exopodite 

 of the first and second maxillipeds of Zoea H 

 through IV apparently distinguish the larvae 

 of Geryon quinquedens from other members of 

 the Brachyrhyncha. In this group the exopodite 

 of the first maxillipeds consistently bear four 

 terminal setae in the first zoeal stage and six 

 in the second stage. The same number is usu- 

 ally associated with the second maxilliped. G. 

 quinquedens bears 4 setae in the first stage and 

 10 or 11 in the second. Knight (1968) reports 

 that the raninid species, Raninoides benedicti 

 Rathbun, has nine setae on the exopodite of the 



second maxilliped (six on the first) of Zoea II. 

 Only members of the rather diverse and remote 

 Anomura apparently bear as many terminal se- 

 tae on the maxillipeds of stages subsequent to 

 Zoea I as does G. quittquedens. The lithodid spe- 

 cies, Cryptolithodes ty pious Brandt, bears four 

 setae on the exopodite of the first maxilliped in 

 the first zoeal stage and eight in the second stage 

 (Hart, 1965) . The porcellanid genera Poly onyx 

 (Knight, 1966; Gore, 1968), Pachycheles, and 

 Petrolisthes (Greenwood, 1965) bear from 11 

 to 14 terminal setae on the exopodite of the first 

 maxillipeds in Zoea II, All bear four setae on 

 this structure in Zoea I. 



ACKNOWLEDGMENTS 



I wish to thank James A. Rollins for making 

 the drawings of the larval stages (Figures 1, 

 6A, and 7A), Warren Rathjen for supplying me 

 with the female crabs, Mary Elizabeth Joralemon 

 and Margaret S. Kelly for assistance in rearing 

 the crab larvae, and Gareth W. Coffin for his 

 reproductions of the illustrations. 



LITERATURE CITED 



BouviER, E.-L. 



1940. Decapodes Marcheurs. Faune Fr. 37, 389 p. 

 Boyden, A. 



1948. Serology and animal systematics. Am. Nat. 

 77:234-255. 

 Brattegard, T., AND C. Sankarankutty. 



1967. On prezoea and zoea of Geryon tridens 

 Kroyer (Crustacea Decapoda). Sarsia 26:7-12. 



Christiansen, M. E. 



1969. Marine invertebrates of Scandinavia. No. 2 

 Crustacea Decapoda Brachyura. Universitets- 

 forlaget, Oslo, 143 p. 

 Costlow, J. D., Jr., and C. G. Bookhout. 



1966. Larval development of the crab, Hexapono- 

 peus angustifrons. Chesapeake Sci. 7:148-156. 



1968. Larval development of the crab, Leptodins 

 agassizii A. Milne Edwards, in the laboratory 

 (Brachyura, Xanthidae). Crustaceana, Suppl. 

 2:203-213. 



Diaz, H., and J. J. Ewald. 



1968. A comparison of the larval development of 

 Metasesarma rubripes (Rathbun) and Sesarma 

 ricordi H. Milne Edwards (Brachyura, Grapsidae) 

 reared under similar laboratory conditions. Crus- 

 taceana, Suppl. 2:225-248. 



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