Deep seaYoldiella(Pelecypoda: Protobranchia: Yoldiidae) from Campos Basin, Rio de Janeiro, Brazil

Abstract

Despite the increasing number of reports on the deep-sea molluscs from the south-western Atlantic, we know very little about the protobranchs. The lack of information on the protobranch Pelecypoda off southern Brazil is reflected in the genusYoldiella. This contribution is part of an effort to increase the knowledge about this group off the Brazilian coast. Eight species ofYoldiellaare recognized here. ForYoldiella biguttata, previously reported from Brazil, the known distribution is extended southwards to the Campos Basin. ForYoldiella similisthis is the first record in the western Atlantic Ocean. ForYoldiella extensaandYoldiellaaff.jeffreysithis is the first record for Brazil. Four previously unknown species are described,Yoldiella lapernoisp. nov.,Yoldiella paranapuaensissp. nov.,Yoldiella arariboiasp. nov. andYoldiella curupirasp. nov. Considering only conchological features for the Atlantic species we could propose some clusters of species ofYoldiella.