Bioecology of the fiddler crab Uca uruguayensis and the burrowing crab Chasmagnathus granulatus (Decapoda, Brachyura) in the Refugio de Vida Silvestre Bahía Samborombón, Argentina

Abstract

The aim of the present work conducted at the Refugio de Vida Silvestre Bahı´a Samborombo´n, Argentina, is to analyse the most relevant aspects of the life cycles of Chasmagnathus granulatus and Uca uruguayensis: their abundance, size distribution and sex ratio in order to be used for make management purposes. A total of 1200 individuals of U. uruguayensis (megalopae, juveniles and adults) and 957 individuals of C. granulatus (juveniles and adults) were collected

Fecundity of Uca uruguayensis and Chasmagnathus granulatus (Decapoda, Brachyura) from the "Refugio de Vida Silvestre" Bahía Samborombón, Argentina

“…The "cangrejal" studied is inhabited by large populations of C. granulatus and U. uruguayensis which coexisted in Samborombón Bay, building their burrows in close proximity to one another (César et al, 2005). They were active during the period studied, except in July 2002 when no individuals from either species were recorded in their burrows (at least up to 50 cm deep) or on the surface.…”

“…Although the population studied in Samborombón Bay has a high density (César et al, 2005), the fact of having collected a low number of ovigerous females could be due to a differential behaviour during this incubation period. Costa et al (2006) captured the ovigerous females very deep in their burrows and suggested that this species would not feed during this period.…”

“…These papers refer mostly to Brazil and the Mar Chiquita Lagoon (Argentina). From them it can be appreciated that reproductive aspects are adaptive processes intimately related with environmental conditions, such as latitude, temperature, larval food availability, giving a single species a continuous reproduction in tropical areas of its distribution and a seasonal one in the temperate zones (Spivak et al, 1991;César et al, 2005;Costa et al, 2006). Dana, 1851 (Varunidae) and Uca uruguayensis (Nobili, 1901) (Ocypodidae) are two endemic species of crabs recorded in the template biogeographic region of the southwestern Atlantic Ocean.…”

“…Both species occupy the high levels of the silty or silt-sandy intertidal ecosystem (Spivak et al, 1991;Spivak, 1997aSpivak, , 1997b and are semi-terrestrial species that build burrows and use the habitat in a rather complex way. Very dense populations of C. granulatus and U. uruguayensis inhabit the intertidal ecosystem of Samborombón Bay (César et al, 2005), giving to the landscape a special physiognomy called "cangrejales". The southernmost permanent populations of U. uruguayensis inhabits Samborombón Bay, however some intermittent populations are found in the Mar Chiquita coastal lagoon, 250 km further south (Spivak et al, 1991).…”

Distribuição geográfica potencial de espécies americanas do caranguejo "violinista" (Uca spp.) (Crustacea, Decapoda) com base em modelagem de nicho ecológico

“…Especificamente, objetivou-se gerar mapas de distribuição potencial dessas espécies e indicar regiões de amostragem com base nos mapas gerados. (CRANE, 1975;BRANCO, 1991;IRIBARNE & MARTINEZ, 1999;ROBALDO & MONSERRAT, 1999;ARMENDÁRIZI & CÉSAR, 2002;THURMAN, 2003;CÉSAR et al, 2005;MASUNARI et al, 2005;ALMEIDA et al, 2006;BEZERRA et al, 2006;MASUNARI, 2006). Este trabalho representa a compilação mais completa de informações desse grupo.…”