Population and reproductive biology of the crab Uca burgersi (Crustacea: Ocypodidae) in three subtropical mangrove forests

Population and reproductive biology were studied in three populations of the crab Uca burgersi Holthuis, 1967, in the Indaiá, Cavalo and Ubatumirim mangrove forests (Ubatuba, São Paulo State, Brazil). Crabs were collected during low tide (August 2001 through July 2002), by digging the sediment, with a standard capture effort (two persons for 30 min.). Carapace width was measured, and gonad developmental stage was recorded from all specimens. U. burgersi was most abundant in the Cavalo mangrove, where the largest male was found. Juvenile crabs were found year-round at all three sites. However, the ratio of ovigerous females was very low, even null in the Cavalo mangrove. The gonad development rate indicated that U. burgersi was reproducing continuously, but more intensively during spring and summer, with recruitment occurring in winter. The synchrony between the populational and reproductive biology in the three areas showed that local features were not the limiting factors. It is suggested that this species is a habitat generalist.

Estudiamos la biología poblacional y reproductiva de tres poblaciones de Uca burgersi Holthuis, 1967, en los manglares de Indaiá, Cavalo y Ubatumirim (Ubatuba, São Paulo, Brasil). Los cangrejos fueron recolectados por excavación de sedimentos, con un esfuerzo de capturaestándar (dos personas por 30 min), durante la marea baja, entre agosto 2001 y julio 2002. En todos los especimenes se midió la anchura del caparazón y se registró la etapade desarrollo gonadal. Esta especie fue más abundante en Cavalo, donde se halló el macho de mayor tamaño.Encontramos juveniles en los tres sitios, durante todo el período de estudio. Sin embargo, la proporción de hembrasovígeras fue muy baja (nula en Cavalo). Según el desarrollo gonadal, el periodo reproductivo fue continuo allí, pero más intenso durante la primavera y el verano, con reclutamiento en el invierno. La sincronía entre la biologíapoblacional y reproductiva de las tres poblaciones, demuestra que las características locales no fueron los factores limitantes. Se sugiere que esta especie es generalista con respecto al hábitat.

Reproductive cycle of Hepatus pudibundus (Herbst, 1785) (Crustacea, Decapoda, Calappidae) in Ubatuba, SP, Brazil

This study aimed to analyze the reproductive cycle of the crab Hepatus pudibundus (Herbst, 1785). The crabs were collected in Ubatuba, SP (23°26'S and 45°02'W) monthly from the July, 1992 to June, 1993. Samplings were performed with an "otter trawl". In the laboratory the crabs were numbered, sexed and measured for their maximum carapace width. The gonad developmental stage and the moult stage were also macroscopically registered. In all sampled months ovigerous females and crabs in both sexes with developed gonad were observed. Moult activity in all size classes was verified. Such fact indicates that this species can suffer moult process after their maturity. In despite of temperature being pointed a one of the most important ecological factor in the reproductive biology of aquatic animals, it was verified any relation between water temperature and ovigerous ratio. The oscillations of the environmental factors in the Ubatuba region sea probably were not enough to alter the continuity of the physiological processes related to H. pudibundus reproduction