Gastrointestinal helminth communities of the blackspot seabream Pagellus bogaraveo (Teleostei: Sparidae) from Portuguese north-east Atlantic waters.

A study was carried out on the gastrointestinal helminth communities of blackspot seabream, Pagellus bogaraveo, from the Portuguese mainland and island waters. Fifteen helminth parasite species were detected, including the following new records in this host: the digeneans Accacladocoelium petasiporum, Brachyenteron helicoleni, Glomericirrus macrouri, Lecithocladium excisum, Lepocreadium album and Pachycreadium carnosum; the nematode Camallanus sp. and the acanthocephalan Rhadinorhynchus pristis. Infection levels were generally low. Samples from mainland waters had a significantly higher prevalence of digeneans than those from the islands, probably due to the greater availability of invertebrate intermediate hosts on the continental slope. The helminth community of P. bogaraveo from Azores was diverse but mostly composed of species that infected no more than a single host, whereas in Madeira the helminth community was very depauperate. Most helminth species exhibited niche preferences within the gastrointestinal tract of the host. Higher functional richness and evenness were obtained in helminth communities of P. bogaraveo from mainland waters, indicating a balanced use of available resources, which is suggestive of more stable gastrointestinal helminth communities in these waters.