Differential habitat use by demographic groups of the redfinger rubble crab Eriphia gonagra (Fabricius, 1781)

Abstract

The structurally diverse rocky shores along the northern coast of the state of São Paulo, Brazil, support a varied fauna and provide refuges for many organisms. Some of these environments allow for extensive microhabitats, among them the sand reefs formed by the polychaete Phragmatopoma lapidosa, which occupy much of this area. The beauty of the landscape attracts large numbers of tourists, who contribute to the damage to the sand reef colonies, causing an imbalance in the patterns of population distribution and of this ecosystem. We describe the structure and population biology of the redfinger rubble crab Eriphia gonagra, and investigated the differential occupation of the habitat by each demographic category of this species. Crabs were sampled monthly for two consecutive years on the rocky coast of Grande Beach, Ubatuba, São Paulo, during spring low tides. Sampling was carried out over an area of approximately 1200 m 2 , during two hours on the rock surface and another two hours on the sand reefs. A total of 1407 crabs were collected; 776 on the sand reef (SR) and 631 on the rocky shore (RO). The majority of juvenile crabs inhabited the SR, while adult crabs were equally distributed in both microhabitats. This study showed that the SR is a natural nursery ground for the establishment of the early juvenile stages of E. gonagra, which use the reefs as a refuge and food resource. Many other organisms (mollusks, echinoderms, polychaetes etc.) settle on the reefs, and these areas may be among the most important in maintaining benthic diversity in the region.Keywords: coastal structures, crab nursery, ecological zonation, Xanthoidea, ontogenetic habitat shift. Ocupação diferencial do habitat por grupos demográficos do caranguejo de dedos vermelhos Eriphia gonagra (Fabricius, 1781) ResumoOs costões rochosos do litoral norte paulista, devido à sua constituição diversificada, sustentam uma grande diversidade de espécies animais e vegetais, além de proporcionar uma série de abrigos para proteção de muitos organismos. Em alguns destes costões ocorre a formação de microhabitats, entre eles os recifes de areia formadas pelo poliqueta Phragmatopoma lapidosa, que ocupam grande parte desta área. A paisagem diferenciada do local atrai um grande número de turistas, o que contribui para a deterioração das colônias que constituem esse recife, causando um desequilíbrio nos padrões de distribuição das populações desse ecossistema. Este trabalho visou levantar informações sobre a estrutura e dinâmica populacional de Eriphia gonagra, além de investigar uma ocupação diferencial do habitat por diferentes grupos etários deste caranguejo. Os caranguejos foram amostrados mensalmente, durante dois anos consecutivos, no costão rochoso da Praia Grande, Ubatuba, São Paulo, Brasil, em períodos de marés baixas de sizígia. A coleta ativa dos indivíduos foi efetuada em uma área de aproximadamente 1200 m 2 por um período de duas horas na superfície rochosa e outras duas horas nos recifes de areia. Foi capturado um total de 1407 indivíduos...

Reproductive features of the swimming crab Callinectes danae(Crustacea, Portunoidea) on the subtropical coast of Brazil: a sampling outside the estuary

“…Andrade et al (2014a) extrapolated this statement in determining the differential distribution of Callinectes ornatus Ordway, 1863 in different states of reproductive potential. Based on the same principles, Andrade et al (2014b) found differential occupation of the habitat by different demographic groups of Eriphia gonagra (Fabricius, 1781). The results of the present study revealed that areas farther the coast were not densely occupied by males and females with rudimentary or developing gonads, which were found in fewer numbers; however, reproductive females were found at depths up to 15 m (see Table 1 and Figure 3).…”

Reproductive investment and multiple spawning evidence in the redfinger rubble crab Eriphia gonagra (Brachyura, Eriphioidea)

“…The available knowledge on this species is related to larval and juvenile development (Fransozo, 1986;Fransozo and Negreiros-Fransozo, 1986;1987;; heterochely, sex ratio, relative growth (Góes and Fransozo, 1997;2000, respectively), fecundity (Góes et al, 2005) and differential habitat use by demographic groups (Andrade et al, 2014). The multiple spawning was suggested to occur in this species (Góes et al, 2005), but no conclusive evidence was provided by authors.…”

“…Eriphia gonagra (Fabricius, 1781) is a common crab in the intertidal zone on the northern coast of São Paulo State, Brazil and it can be find in rocky shores or living associated with colonies of Phragmatopoma (Polychaeta, Sabellariidae) (Andrade et al, 2014). The available knowledge on this species is related to larval and juvenile development (Fransozo, 1986;Fransozo and Negreiros-Fransozo, 1986;1987;; heterochely, sex ratio, relative growth (Góes and Fransozo, 1997;2000, respectively), fecundity (Góes et al, 2005) and differential habitat use by demographic groups (Andrade et al, 2014).…”

Habitat-related phenotypic variation in adult Western Atlantic stone crabs (Menippe mercenaria Say, 1818) (Decapoda: Brachyura)

“…Habitat partitioning by different life stages and/or phenotypes within a species in a heterogeneous environment could confer fitness advantages. For example, habitat partitioning occurs across taxa for reproduction (Campbell, 1986;Hooper, 1986;Bowyer et al, 2002), molting (Hines et al, 1987), life history stages (Kanciruk and Herrnkind, 1978;Hatase et al, 2002;Andrade et al, 2014), and phenotypic variants (Shine et al, 2012). Individuals of varying color patterns could select different habitat types for camouflage (Endler, 1984;King, 1993;Guinot and Wicksten, 2015), to facilitate antipredator behaviors (Brodie, 1989), or for optimal thermal strategies (Wilkens and Fingerman, 1965).…”