Annotated checklist of Echinoderms from Maranhão and Piauí States, Northeastern Brazil

The present study provides the first checklist of echinoderm species that occurs in the States of Maranhão and Piauí, in Northeastern Brazil. The present compilation was produced based on an extensive bibliographical revision and on echinoderms deposited in the Invertebrate Collection Paulo Young, Federal University of Paraíba. Twenty-two species were listed, distributed into the classes Asteroidea (2 spp.), Ophiuroidea (16 spp.), Echinoidea (2 spp.), and Holothuroidea (2 spp.). The registered echinoderm diversity adds significantly to our faunistic knowledge, considering that no previous systematic compilation of echinoderms exists for this region.