Metazoan fish parasites of Segara Anakan Lagoon, Indonesia, and their potential use as biological indicators

The present study reports metazoan fish parasites from Segara Anakan, a brackish water lagoon located at the southern Java coast, Indonesia. Seven economically important marine fish species (Mugil cephalus, Siganus javus, Scatophagus argus, Caranx sexfasciatus, Lutjanus johnii, Eleutheronematetradactylum and Johnius coitor) were examined at two different sampling sites within the lagoon for the occurrence of metazoan parasites. A diverse parasite fauna was found, consisting of 43 species/taxa. Ectoparasites (31) were more abundant than endoparasites (12). The fish species J. coitor, M. cephalus and S. argus harboured the most diverse metazoan parasite fauna with 11, 13, and 16 different parasite species, respectively. Prevalence and intensity of infection for each parasite species/taxon is given, including short descriptions for rapid diagnosis. For the first time, we discuss the utilisation of the sampled fish parasites as biological indicator organisms for fish and environmental health within this tropical mangrove ecosystem. Ecto- versus endoparasite ratio and endoparasite diversity are suitable tools to describe the environmental health status at a tropical brackish water locality, and might be applied also for other tropical and possibly non-tropical marine ecosystems.