Crustacean communities in coastal ephemeral pools in the Araucanía region (38° S, Chile).

The fauna communities of ephemeral pools in southern Chile are characterized by heterogeneity of crustacean taxa; nevertheless, no detailed studies exist of their community structure. The aim of the present study was to analyze the crustacean community structure in two groups of ephemeral pools (Puaucho and Nigue pools) in the coastal zone of the Araucanía region. A correlation matrix was made by species abundance against temperature, conductivity, pH and total dissolved solids. In a second step, a null model for species co-occurrence was applied to the total data and to each group. The results for total data revealed a significant direct relation between the abundance of H. costera, C. dubia and Mesocyclops. For the Puaucho pools, the same results were found together with direct associations with total dissolved solids, conductivity and pH. Finally, different results were found for the Nigue pools, with no clear significant associations, either direct or indirect, between the abundance of different crustacean taxa and abiotic parameters. These results were supported by the co-occurrence null model analysis, which revealed the presence of regulator factors for the total data, and for each of the two groups. Ecological topics are discussed with emphasis on meta-community dynamics.