Free-living marine nematode communities from Patagonian coastal lagoons?

CATALINA T. PASTOR; RICHARD M. WARWICK

Brisbane, Australia 13-18 July

Congreso; 5th International Congress of Nematology; 2008

Asociación Internacional de Nematólogos

Summary: This paper describes a baseline study on nematode biodiversity from three different latitudes (Península Valdes, 43ºS; San Julián, 49ºS and Río Gallegos, 51ºS in Chubut and Santa Cruz provinces) contrasting coastal upper littoral marine areas with saline coastal lagoons in Patagonia. The lagoons vary in salinity from hypersaline to almost fresh water. The objective of the study was to give the first inventory of the fauna of these habitats, in particular a detailed study of the dominant taxa the free-living marine nematodes. Fitfteen lagoons and three upper littoral coastal areas have been sampled at the three latitudes. The samples have been fixed in 5% formalin with rose Bengal in the field. The geographical position (GPS), salinity and granulometry, 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.The differences in nematode species composition between latitudes and environments were analysed by multivariate methods. The results indicate that salinity and elevation above sea level seem to be the main environmental variables that explain the complex distribution found. Lagoons near the sea have similar nematode fauna to coastal littoral sites, and inland lagoons have a particularly extreme nematode fauna associated with the salinity regimes. Detailed information about species found plus dominant genera at each latitude will be presented.This project was support by Royal Society of London, UK and CONICET, Argentina.