Two new species of free-living marine nematodes of the family Oxystominidae Chitwood, 1935 (Enoplida) with a review of the genus de Man, 1893 from the Argentine coast.

Two new free-living marine nematodes of the family Oxystominidae are described from San Antonio Bay (Río Negro) and San José Gulf (Chubut). Litinium australis sp. n.

Free-living marine nematodes from San Antonio Bay (Río Negro, Argentina).

The dataset of free-living marine nematodes of San Antonio Bay is based on sediment samples collected in February 2009 during doctoral theses funded by CONICET grants. A total of 36 samples has been taken at three locations in the San Antonio Bay, Santa Cruz Province, Argentina on the coastal littoral at three tidal levels. This presents a unique and important collection for benthic biodiversity assessment of Patagonian nematodes as this area remains one of the least known regions.

A new species of Pontonema (Oncholaimidae, Nematoda) and a redescription of Pontonema incisum Wieser, 1953 from Santa Cruz and Chubut Provinces, Argentina.

Pontonema golfonuevensis sp. nov. from Chubut Province, Argentina is described and a description of the male of Pontonema incisum Wieser, 1953 from Chubut and Santa Cruz Provinces is provided.

Two new species of Parasaveljevia Wieser, 1953 (Thoracostomopsidae, Nematoda) from Argentinean coasts (Chubut, Argentina).

Two new Parasavaljevia species are described, one from Puerto Madryn, and one from El Límite beach, San Jorge Gulf, Chubut Province, Argentina. The two species are characterised by a combination of characters. Parasavaljevia uncinoa n.

Two new species of Parasaveljevia Wieser, 1953 (Thoracostomopsidae, Nematoda) from Argentinean coasts (Chubut, Argentina).

Two new Parasavaljevia species are described, one from Puerto Madryn, and one from El Límite beach San Jorge Gulf, Chubut Province, Argentina. The two species are characterised by a combination of characters. Parasavaljevia uncinoa n.

Free-living marine nematodes from San Julián Bay (Santa Cruz, Argentina).

The free-living marine nematodes of San Julián Bay dataset is based on sediment samples collected in January 2009 during the project PICT AGENCIA-FONCYT 2/33345-2005. A total of 36 samples have been taken at three locations in the San Julián Bay, Santa Cruz Province, Argentina on the coastal littoral at three tidal levels. This presents a unique and important collection for the nematode benthic biodiversity assessment as this area remains one of the least known regions in Patagonia.

Three new species and one new record of Campylaimus (Diplopeltidae, Nematoda) from Argentine coasts (Buenos Aires and Santa Cruz, Argentina).

Two new Campylaimus species from Arroyo Pareja, Buenos Aires province and one new species and one new record of Campylaimus from Puerto San Julián, Chubut province are described. The three species are characterized by the shape of the copulatory apparatus of the male and the presence of precloacal papillae. Campylaimus bonariensis sp.