Accepted by B. Adams: 7 Dec. 2006; published: 1 Feb 2007 39 ZOOTAXA ISSN 1175-5326 (print edition) ISSN 1175-5334 (online edition) Copyright © 2007 · Magnolia Press Zootaxa 1402: 39–57 (2007) www.mapress.com/ zootaxa/ Four new species of Sabatieria Rouville, 1903 (Nematoda, Comesomatidae) from the Continental Slope of Atlantic Southeast ALESSANDRA PRATES BOTELHO; MARIA CRISTINA DA SILVA; ANDRÉ MORGADO ESTEVES;VERÔNICA FONSÊCA-GENEVOIS Universidade Federal de Pernambuco, Av. prof. Moraes Rêgo, S/N, Depart. Zoologia. Cidade Universitária, Recife – Pernambuco, Brazil. CEP 50670-901. luna_soleil@yahoo.com Abstract Sabatieria is the most abundant genus along the Campos Basin, Rio de Janeiro (Brazil). Four new species of Sabatieria (Nematoda-Comesomatidae) from the Continental Slope of Atlantic Southeast are described. Sabatieria spiculata sp.nov . is characterized by the size of spicule and the presence of dorsal tooth ; S. paraspiculata sp. nov. by tail shape and the maximum diameter; S. bitumen sp. nov. by spicule shape with an arrow-like distal part and the S. subrotundi- cauda sp.nov. by a round tail and reflected ovary. Key words: Free-living marine nematodes, Sabatieria, Comesomatidae, deep-sea, silty sediments Introduction The nematode community structure in Campos Basin did not differ significantly from other deep-sea data worldwide, showing low densities, low dominance and very high richness. Netto et al. (2005) studying the same area found similar community structure, with a strong bathymetrical boundary between continental slope and deep sea stations. The number of genera (193) and families (44) are the highest recorded in deep-sea (Fonsêca-Genevois et al. 2005). Most of the genera (42%) were present from 500 m to 1950 m depth, but con- sidering species distribution among the genera, diversity not only increases with depth but also spatial hetero- geneity may become extremely more evident (Lira 2005). Sabatieria is the most abundant genus along the Campos Basin accounting to 50% of the total nemato- fauna (Fonsêca-Genevois et al. 2005). Sabatieria spiculata sp. nov., S. paraspiculata sp. nov. and S. bitumen sp.nov. presented a continuous spatial distribution, whereas the S. subrotundicauda sp. nov. was only found at the upper slope. Study area The continental slope of Campos Basin has a width varying from 120 km to 150 km, with the lowest limits between 2.400 m and 3.000 m depth. It is covered by fine continental sediment and a sandy fraction which is composed mainly of Foraminifera (Soares-Gomes et al.1999). This Basin is located on the continental shelf and slope of Rio de Janeiro State, between 21 o 30' and 23 o 30' S (Figure 1).