First records of the order Polycladida (Platyhelminthes, Rhabditophora) from reef ecosystems of Alagoas State, north-eastern Brazil, with the description ofThysanozoon alagoensissp. nov.

Abstract

The 230 km long coast of Alagoas State, in north-eastern Brazil, has diverse reef ecosystems, made from corals and of sandstone, that harbour a wide range of marine invertebrate fauna. Little is known about turbellarians of the order Polycladida in most parts of the Brazilian coast, with no record from Alagoas up to date. To fill this gap expeditions were conducted on the reefs from the central coast of Alagoas, where 11 Polycladida species were found:Pericelis cata, Enchiridium evelinae, Pseudoceros bicolorand a possible new colour variation of this species,Pseudoceros rawlinsonae, Pseudobiceros pardalis, Thysanozoon brocchii, Thysanozoon alagoensissp. nov.,Armatoplana leptalea, Adenoplana evelinae, Latocestus brasiliensis, Phaenocelis medvedica. The species are described in detail through photos of live specimens and histological sections. The present work adds six species to the north-eastern Brazilian coast, one of them a new species, and all 11 species are for the first time reported from Alagoas State. Also, it is the first time thatPhaenocelis medvedica, Adenoplana evelinae, Latocestus brasiliensisandArmatoplana leptaleaare illustrated by full colour photos of live specimens and histological sections.