The assemblage of Laeonereis acuta Treadwell, 1923 (Polychaeta, Nereididae) in the Bahia Blanca, Argentine

The structure, distribution and relationship with environmental factors were described for the Laeonereis acuta association in the Bahia Blanca. The 22 stations were sampled in spring. At each one, six 0.12 m-2 van Veen grabs were taken in tidal creeks at low tide. Cluster analyses were performed to summarized associations, with quali and quantitative index in Q and R mode. Into the inner bay, the characteristic species are L. acuta and Corophium sp., while in the outer are Neanthes sp. and Priapulus tuberculatospinosus Baird, 1866. Heleobia australis is a preferent species in the association, with major dominance into the inner bay than in the outer. The salinity and granulometric pattern agree with other studies carried out on this association. The faunistic composition of the association change along the geographical distribution from the brazilian to the Argentinean coast.