No abstract

RESUMEN. Las larvas de Pachycheles chubutensis eclosionan como prezoea y tienen una vida de 10-15 min antes de transformarse en zoea I, que tiene una longitud total que varía entre 9,5 y 11,9 mm. Presenta un caparazón globoso de 1,6-1,8 mm de longitud desde donde emerge en la región anterior una espina rostral de 7,05 mm (± 0,42 mm) de largo y en la región posterior dos espinas caudales iguales de 3,1 mm (± 0,62 mm). Tanto la espina rostral como las espinas caudales muestran en toda su superficie ventral una serie de espínulas. Los ojos son sésiles. Las mandíbulas son asimétricas, con procesos dentados rígidos. El tercer maxilípedo está ausente. El telson presenta el borde posterior convexo con siete pares de procesos posteriores.

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. In total 10,030 specimens of free-living marine nematodes belonging to 2 classes, 9 orders, 35 families, 78 genera and 125 species were collected. The San Julián city site presented a very high species richness.

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. In total 7,743 specimens of free-living marine nematodes belonging to two classes, eight orders, 37 families, 94 genera and 104 species were collected.

The aim of this study was to investigate the patterns of nematode diversity and community structure in San Jorge Gulf, Argentina, in order to improve knowledge of this key group of organisms. Free-living marine nematodes were sampled at 13 stations in February 2014 during an expedition aboard R/V Coriolis II. We found a total of 188 species (101 of which were new to science) belonging to 98 genera. The statistical results indicated the presence of three different assemblages of free-living marine nematodes distributed spatially in three distinct zones in the gulf: the central part, the outer thermal front at both sides of the entrance, and the south thermal front area. Diversity increased from the coast to the entrance of the gulf, and the highest diversity was found in areas with coarser sediment. Sediment and salinity were the environmental parameters that best matched nematode community distribution.