Abstract The study investigated the population parameters of the shrimp Xiphopenaeus spp. (commonly known as seabob shrimp) in Anchieta, south coast of the state of Espírito Santo, Brazil, focusing on reducing the sampling effort. Shrimp were collected between February 2013 and February 2015. Individuals were measured, analyzed for sex and stage of reproductive development. In total, 1,564 individuals were analyzed in Anchieta, 534 males (74 juveniles and 460 adults) and 663 females (88 juveniles and 575 adults), and 367 individuals were not identified to sex or maturity. Significant differences were observed in shrimp abundance, with higher catches at the shallowest sampling point and associated with the type of substrate (silt+clay), while in the rainy season (September to March) and dry season (April to August) there were no significant differences. Despite this, greater abundances were found in the rainy season. The sex ratio was 0.80♂: 1♀. Carapace length ranged from 5.7 to 28.9 mm, with larger sizes recorded for females, as well as a larger size at first maturation than males, 12.86 and 11.60 mm respectively. All stages of development of the seabob shrimp were observed at the sampling points and periods, which represents a pattern of continuous reproduction and recruitment of the species in the area. Considering the sample size used, which is comparatively smaller than other studies, all estimates confirm current knowledge about the biology of the species and provide robust data on the seabob shrimp off the Anchieta coast, which are necessary for management and conservation.

O objetivo do presente estudo foi caracterizar a composição e a abundância dos caranguejos no infralitoral não-consolidado de duas regiões (Ubatuba e Caraguatatuba) do litoral norte paulista, Brasil. Em cada região foram realizadas coletas mensais em sete profundidades, durante o período de dois anos (Julho/ 2001 a Junho/ 2003), utilizando-se um barco de pesca equipado com duas redes do tipo "double-rig". Obteve-se um total de 30.231 caranguejos (13.305 em Ubatuba e 16.926 em Caraguatatuba), abrangendo nove superfamílias (Dromioidea, Homoloidea, Calappoidea, Leucosioidea, Majoidea, Parthenopoidea, Portunoidea, Xanthoidea e Pinnotheroidea), 16 famílias, 29 gêneros e 44 espécies. Do total de espécies coletadas, 31 foram comuns para as duas regiões. Dentre as duas regiões, Caraguatatuba apresentou a maior riqueza de espécies (42) e o maior índice de diversidade (2,93 bits/inds.). Para ambas regiões, Callinectes ornatus, Hepatus pudibundus e Libinia spinosa, foram os braquiúros mais abundantes. Tais resultados indicam que as duas regiões analisadas apresentam ambientes propícios para o desenvolvimento dos braquiúros, possibilitando uma alta biodiversidade.

The objective of the present study was to characterize the composition and abundance of the marine brachyuran crabs in non-consolidated sublittoral sediments in two regions, Ubatuba and Caraguatatuba, on the northern coast of São Paulo State, Brazil. In each region, collections were made monthly at seven depths for two years, July 2001 through to June 2003, from a fishing boat equipped with two double-rig nets. A total of 30,231 crabs were caught (13,305 at Ubatuba and 16,926 at Caraguatatuba), representing nine superfamilies (Dromioidea, Homoloidea, Calappoidea, Leucosioidea, Majoidea, Parthenopoidea, Portunoidea, Xanthoidea and Pinnotheroidea), 16 families, 29 genera and 44 species. Among the total species collected, 31 were common to both regions. Caraguatatuba showed higher species richness (42) and a higher H' diversity index (2.93). For both regions, Callinectes ornatus, Hepatus pudibundus and Libinia spinosa were the most abundant brachyurans. The results indicate that the two regions provide favorable environments for brachyurans, resulting in a locally high biodiversity.