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Benthic samples collected along the Brazilian central continental margin from Espírito Santo State to Rio de Janeiro State (19° S to 24° S) during the last 20 years and at depths of 50–2200 m yielded the description of six new species of Typhlotanais in the deep-sea (> 200 m): Typhlotanais andradeorum sp. nov., T. bolarticulus sp. nov., T. ischnochela sp. nov., T. longiseta sp. nov., T. priscilae sp. nov. and T. spinibasis sp. nov. Within these species, we found members of four Typhlotanais morpho-groups as ‘cornutus’ group, ‘greenwichensis’ group, ‘spinicauda’ and ‘trispinosus’ group. Typhlotanais ischnochela sp. nov. exhibited the greatest bathymetric range, occurring from the continental shelf until the lower slope (46–1898.7 m depth). The bathymetric distribution of the other five species of Typhlotanais herein described were restricted to the slope. Tables of diagnostic characters of the Typhlotanais morpho-groups and an identification key to the species of Typhlotanaidae found in Brazil are provided. This work brings the total number of Tanaidacea known for Brazilian coast to 64 species, and the family Typhlotanaidae from Brazil is now represented by 11 species in five known genera.
The Selachinematidae is a globally distributed family of predatory nematodes found from shallow waters to the abyssal plain. Here, three new species of Halichoanolaimus de Man, 1886 (H. ossilagulus sp. nov., H. funestus sp. nov. and H. pumilus sp. nov.) and one known species (H. ovalis Ditlevsen, 1921) are described from the New Zealand continental margin, thus bringing the total number of selachinematid species recorded from the New Zealand region to 14 and the total number of species of Halichoanolaimus to 26. The range of H. ovalis is extended from the Southern Ocean to the Southwest Pacific Ocean (latitude 42° S to 53° S); the depth range of this species, which was originally described from the littoral zone, is also extended to 1061 m depth. Dorsosublateral rows of pore complexes and pseudocoelomocytes, features that have either rarely or not been recorded previously in the genus, were observed in all four species described here. The taxonomic significance of these features remains to be ascertained for the family and will require observations of other species of Halichoanolaimus and selachinematid genera. Pseudocoelomocytes and pore complexes may have an excretory function, thus aiding to process the waste products of digestion in selachinematid taxa with a blind intestine.