First record of the non-native copepod Pseudodiaptomus trihamatus Wright, 1937 (Copepoda, Calanoida) in Rio de Janeiro state, Brazil

This note presents the first record of P. trihamatus in southeastern Brazilian coast (Rio de Janeiro state), handing an updated scenario of its distribution and helping understand its environmental requirements for dispersion and establishment in new environments. The occurrence of P. trihamatus was observed in October 2015 in a plankton sample from Açu lagoon, located between Campos dos Goytacazes and São João da Barra Municipalities, Rio de Janeiro state, during biological surveys carried out for two years. We filtered 200 L using 50 μm plankton net and fixed with 4% formalin solutions. Salinity was measured by a portable Hanna Multiparameter.(AU)