Parasite assemblages of Nemadactylus bergi (Pisces: Latridae): the role of larval stages in the short-scale predictability

The short-scale temporal repeatability in the structure and composition of parasite communities of Nemadactylus bergi were analyzed by comparing population and infracommunity descriptors in five samples caught off Mar del Plata, Argentina (38A(0) 27' S, 57A(0) 90' W) at intervals of 20 days. This is the first study aiming to detect relevant local or short-term processes in an area where larval endohelminths dominate the parasite assemblages and are expected to provide predictability to the communities they belong. The parasite fauna of this host species was composed by 18 species, 16 of them being endoparasites, among which larval stages accounted for most of both the number of parasite individuals found and the highest percentages of average similarity among infracommunities. The structure of parasite communities of N. bergi was, as predicted, repeatable across samples at short spatial and temporal scales and, as expected, this predictability was mainly provided by larval stages, namely Corynosoma australe and Grillotia carvajalregorum. These results imply that a single sample of N. bergi from this locality will be enough to catch the structure and intrinsic variability of their component communities in further studies aiming to compare parasite assemblages at larger spatial scales. These studies should, however, take into account the heterogeneity in the size of fish among samples, which proved to be an important confounding factor in comparisons among samples by affecting their similarity.