COMPARATIVE ANALYSIS OF THE MATURE GONADS IN OCYPODIDAE CRABS FROM SOUTH AMERICAN EAST COAST

NEGREIROS-FRANSOZO1, M. L.; LOPEZ-GRECO2,3, L.S.; SANTOS1, 4, D.C. AND V. FRANSOZO1

Coquimbo, Chile

Congreso; Mid-Year Meeting of the Crustacean Society; 2007

The Crustacean Society

COMPARATIVE ANALYSIS OF THE MATURE GONADS IN OCYPODIDAE CRABS FROM SOUTH AMERICAN EAST COAST   Negreiros-Fransozo1, M. L.; Lopez-Greco2,3, L.S.; Santos1, 4, D.C. and V. Fransozo1   1 NEBECC (Crustacean biology, ecology and culture study group), Dept. Zoologia, Instituto de Bioci¨ºncias, UNESP, 18618-000 Botucatu, SP, Brasil. mlnf@ibb.unesp.br vifransozo@ibb.unesp.br; 2 Dept. of Biodiversity and Experimental Biology, FCEyN, University of Buenos Aires, Cdad. Univ. C1428EHA, Buenos Aires, Argentina; 3CONICET. laura@bg.fcen.uba.ar; 4Dept. Morfologia, Instituto de Bioci¨ºncias, UNESP, 18618-000 Botucatu, SP, Brasil daniela@ibb.unesp.br   Ocypodidae crabs, namely Ucides cordatus and several Uca species, inhabit mainly estuaries and mangrove bottoms and Ocypode quadrata lives on sand shores from South American east coast. Although many aspects about their reproductive biology are known, such information is dispersed and it has not been studied from a comparative point of view. This research was aimed at comparing the gonad morphology of Ucides cordatus, Ocypode quadrata, Uca rapax and U. uruguayensis at histological level. Mature crabs were sampled in Brazilian coast and processed following routine procedure for histological analyses. Only crabs in intermoult period and with well developed gonads were used in the present study. For the males, the size of the spermatophores was measured and the number of spermatozoa/spermatophore in each section was estimated, while for females, the size of the oocytes was measured. The spermatophores of the four species have oval shape and they differ (ANOVA on ranks; ¦Á = 0.05) in size (O. quadrata > U. cordatus > U. uruguayensis > U. rapax) and in the number of spermatozoa/spermatophore (U. cordatus > O. quadrata > U. uruguayensis > U. rapax). Concerning mature female gonads, in all studied species, the ovarian wall lacks muscular cells, oogonias are rarely observed and the predominant cellular stage (higher than 85 %) is the oocyte in secondary vitellogenesis, characterized by its large size and cytoplasm totally filled with yolk platelets and globules. The mean oocyte diameter of primary and secondary stages reveals two groups: one for Uca with smaller mean diameter and other one for Ucides-Ocypode species with larger mean diameter (ANOVA; ¦Á = 0.05). The observed differences might be associated to the terrestrially degree experienced by these ocypodid crabs (Ucides-Ocypode>Uca), other reproductive features as the fecundity, mating behavior mechanisms or even phylogenetic relationships among these studied genus.   Financial support: CNPq/Prosul#490208/2005 PORTER PRESENTATION