Density of larval and adult forms of the burrowing crustaceansLepidophthalmus siriboia(Callianassidae) andUpogebia vasquezi(Upogebiidae) in an Amazon estuary, northern Brazil

Abstract

Although thalassinidean shrimps exert considerable influence over the structure of benthic communities no ecological studies have been conducted on the larvae and adults ofLepidophthalmus siriboiaandUpogebia vasqueziin the equatorial region. The aim of the present study was to identify the reproductive period of these species in an Amazonian estuary. Monthly collections were performed in the estuary of the Marapanim River (northern coast of Brazil) over the course of one year (August 2006 to July 2007) and adults were obtained from bare sandy substrate and between boulders in the intertidal zone of the estuary at four sites. Thalassinidean larvae were also sorted from plankton samples (200 μm mesh) collected monthly at six sites. Larvae of the speciesCallichirus major, Lepidophthalmus siriboiaandUpogebia vasqueziwere collected, whereas adults of only the latter two species were found.Upogebia vasqueziwas the most abundant species. There was no correlation between larval density and abiotic factors (water temperature, salinity and pH); however, the density ofU. vasqueziadults was negatively correlated with salinity in the burrows.Lepidophthalmus siriboiaandU. vasquezireproduce throughout the year in the Marapanim River estuary, with peaks of greater intensity in some reproductive periods of the year, mainly correlated with changes in salinity.