Population structure of Aegla castro Schmitt, 1942 (Crustacea: Anomura: Aeglidae) from Itatinga (SP), Brazil

FRANSOZO, A.¹, COSTA, R. C.¹, REIGADA, A. L. D. ¹ & NAKAGAKI, J. M. ^1,2

¹ NEBECC (Núcleo de Estudos em Biologia, Ecologia e Cultivo de Crustáceos), Depto de Zoologia, Instituto de Biociências, Universidade Estadual Paulista -UNESP – 18618-000 - Distrito de Rubião Jr. S/N – Botucatu (SP) – e-mail: fransozo@ibb.unesp.br

² Cidade Universitária de Dourados, s/nº - Universidade Estadual do Mato Grosso do Sul - UEMS - Dourados/Itahum, Km 12 – 79804-970 – Dourados (MS).

ABSTRACT: The population structure and the reproductive period of Aegla castro were studied herein aiming to acquire a better knowledge of this group and its role in limnic ecosystems. The anomurans residing Itaúna river at Itatinga, São Paulo, Brazil (23^o 08’ S and 48^o 39’ W) were monthly sampled from January to December, 1991. A total of 732 specimens were captured, 382 males and 350 females from which 17 were ovigerous. As far as their sex and carapace length are concerned (CL), mean animal size did not differ between sexes although males achieved greater dimensions. Ovigerous females occurred only during May and June characterizing a discontinuous reproductive cycle, while the recruitment of juveniles took place in October and November. Sex-ratio follows 1:0.92 (males:females). Comparatively, A. castro presents a similar population structure to its congenera species and as for the reproductive periodicity, it seems to decrease its period as latitude gets lower.

Key-words: population biology, recruitment, Aegla, Anomura.