Brachyuran and anomuran crabs associated with Schizoporella unicornis (Ectoprocta, Cheilostomata) from southeastern Brazil

Abstract

The main goals of this investigation were to describe the community structure of anomuran and brachyuran crabs inhabiting reefs constituted by colonies of Schizoporella unicornis, and to provide a species importance ranking for this community. Collections were carried out on S. unicornis reefs at two-month intervals from May 2003 to May 2004, in the rocky sublittoral of the southeastern Brazilian coast. Relative abundance and occurrence were used to rank these species in the hierarchy importance. A total of 2,018 individuals were obtained, in 11 families, 22 genera and 31 species. Porcellanidae and Pilumnidae were the most abundant families, comprising respectively almost 60% and 15% of individuals sampled. The species ranking indicated four main groups A, B, C and D, with group A subdivided. Subgroup A1 contained 9 species, including the species of greatest ecological importance for community regarding abundance and occurrence. The great abundance of crabs associated with S. unicornis seems to be the result of its recognized importance during the crab developmental cycle, and as shelter and food for some Decapod species. These observations reveal the importance of conserving the areas occupied by these reef colonies, which appear to be an important environment for maintaining local biodiversity.

Macrofauna associated with a recently described bryozoan species in the Eastern Harbour of Alexandria, Egypt

“…Morgado and Tanaka (2001) observed the dominance of the isopod Excorallana quadricornis and the decapods Pachycheles maginanus and Hexapanopeus schmitti on S. errata, while on C. alexandriensis decapods were mostly found in low counts, except for the locally relatively high count of Alpheus lobidens in spring. During the present study, decapods were represented by 4 species only against 23 species associated with the bryozoan S. pungens in Florida (Lindberg & Stanton, 1988), 24 species with S. errata in Brazil (Morgado & Tanaka, 2001), and 31 species of crabs with S. unicornis in the northeastern coast of São Paulo State, Brazil (Alves et al, 2013). The differences in diversity of associated fauna may be also due to differences in local water currents affecting recruitment or higher abundance of predatory and territorial decapods (Duarte & Nalesso, 1996).…”

Importance of biogenic substrates for the stone crab Menippe nodifrons Stimpson, 1859 (Brachyura: Eriphioidea)

“…All sampling was carried out bimonthly, during two years, in low-tide periods, with a catch per unit effort of two persons during 2 h each month, totaling 4 h of catch effort per month and per substrate. The biogenic substrates used in this study were chosen based on previous studies, such as those of Fransozo et al (2000); Barros-Alves ( 2009) and Alves et al 2013. In the laboratory, the maximum carapace width (CW) of crabs was measured with a vernier caliper (0.1 mm). Crab sex was determined by observing the external morphology of the abdomen (in males the abdomen is triangular, and in females it is oval), and number of pleopods (males with 2 pairs and females with 4 pairs of pleopods).…”

“…Popularly known in Brazil as "Guaiá", Menippe nodifrons Stimpson, 1959, has a wide geographical distribution in the western Atlantic, from Florida to southern Brazil, and with records for the eastern Atlantic, from Cabo Verde to the Angola coast (Melo, 1998). It occurs mainly on rocky shores, from the intertidal to 10 m deep, in rocky crevices or in association with biogenic substrates (Melo, 1998;Fransozo et al, 2000;Alves et al, 2013).…”

Population structure of the swimming crab Achelous spinicarpus (Crustacea, Portunoidea) in São Paulo northern coast, Brazil

“…Due to SACW influence and other peculiarities of the southeastern Brazilian coast, this locality has been the target of many community studies involving species richness, abundance and diversity of decapod crustaceans, in order to better understand the dynamics of the region's biodiversity (Fransozo et al, 2012;Bertini et al, 2010a;De Léo and Pires-Vanin, 2006;Alves et al, 2013;Furlan et al, 2013;Andrade et al, 2015a). Despite the large number of studies involving the decapod crustacean community on the north coast of São Paulo, studies at more specific ecological levels, such as populations, are necessary to understand the interactions that determine the biotic dynamics in these environments (Mantelatto et al, 1995;Braga et al, 2007).…”