New species of Perissocytheridea (Crustacea, Ostracoda, Cytheridae) from the intertidal zone of a coastal island in Eastern Amazonia

Abstract

This study investigated the ostracods in the intertidal zone on Algodoal Island, on the northeast of Pará state, Brazil. These environments are poorly studied, especially regarding the taxonomy of these small crustaceans. Samples were collected in three beaches (Caixa D’Água, Princesinha, and Princesa) during low tide, in different seasons of the year (dry and rainy). In addition to sampling ostracods, the pH, salinity, and water temperature were measured. The results indicated low ostracods diversity, with the genus Perissocytheridea predominating, and a new species described. Salinity was the environmental parameter that varied most between periods (0 to 30 ppm), with Perissocytheridea materterrae sp. nov. recorded between 0 and 20 ppm. This result reinforces the genus’s preference for brackish environments and its potential use as an ecological bioindicator. The ostracod records were restricted to Caixa D’Água Beach, which, due to its smooth topography and lower hydrodynamic energy, provided a suitable refuge for these organisms.