Preliminary Observations on Nematodes from Coastal Patagonian Sediments (Chubut, Argentina)

LO RUSSO, V.; PASTOR, C. T.

Brisbane

Congreso; 5th International Congress of Nematology; 2008

Australasian Association of Nematologists

This paper focuses on two new species belonging to Neochromadora (CHROMADORIDAE) and Cobbia (MONHYSTERIDAE), two very cosmopolitan genera inhabiting coastal sediments systems, providing their distribution on East coastal Patagonia. Seven littoral areas have been sampled at three latituds. The samples have been fixed in 5% formalin with rose Bengal in the field. The geographical position (GPS), salinity, temperature, granulometry, organic matter, DPR layer and dissolved Oxygen have been taken. Nematodes were extracted using the elutriation/decantation/LUDOX TM method and specimens mounted on slides. The Nematodes found were identified up to the lowest taxonomy level possible, and photographs were taken using a Photomicroscope. For nematode identifications the keys of Platt & Warwick and Warwick et al. were used. Two probably new species belonging to these two genera are described from Patagonia coastal areas, Chubut province of Argentina: Neochromadora sp. Is characterized by gubernaculums and spicules shape, the presence of a thick cuticle plate on subventral tail area; esophageal bulb shape and length of cephalic and somatic setae. It has been found in upper to low littoral sandy areas. Cobbia sp. Is characterized by the amphid position and size and length of cephalic setae. It has been found in low littoral sandy beaches. These species have been described in the project titled: "Biodiversity of meiofauna communities in sand beaches of Río Negro and Chubut" supported by GEF- Secretaría de Medio Ambiente de Nación - CONICET, Argentina.