Two new species of Hemicyclops (Copepoda: Poecilostomatoida: Clausidiidae) associated with mud shrimps of the genus Callichirus from Brazil

Two new clausidiid copepods of the genus Hemicyclops (Poecilostomatoida: Clausidiidae) associated with mud shrimps are described from Brazil: Hemicyclops caissarum sp. n. associated with Callichirus major (Say, 1808) from a beach in Santos and Hemicyclops sebastiani sp. n., in burrows of Callichirus guassutinga (Rodrigues, 1971) in São Sebastião. H. caissarum is closest to H. carinifer Humes, 1965 from Madagascar and H. sebastiani can be easily distinguished from all its congeners by the presence of a thick, densely plumose seta on the antennule segment 2, and the greatly enlarged tergal plate of the 4th pediger. New records of Hemicyclops subadhaerens Gooding, 1960 and Hemicyclops thalassius Vervoort & Ramirez, 1966 from the Brazilian coast are also included.