Carbon sources supporting Australia's most widely distributed freshwater fish, Nematalosa erebi (Günther) (Clupeidae: Dorosomatinae)

Both brown (detrital-based) and green (algal-based) food pathways support freshwater webs, although the importance of either source may vary within species, regions different phases flow regime. The bony bream (Nematalosa erebi Clupeidae: Dorosomatinae) is one Australia’s most widely distributed fish species a key component especially in northern Australia. We sought to better define feeding habits this previously classified as detritivore, algivore or zooplanktivore (or combinations thereof), by undertaking meta-analyses published accounts based on stomach content analysis 13C 15N stable isotope analysis. Stomach clearly indicated that detritus was dominant item, benthic algae could be an important dietary some habitats (inland river flood plains) during wet season. Zooplankton were for small (i.e. juveniles <100mm length). When data pooled across large number locations, derived from terrestrial vegetation aligned isotopically with values both adult juvenile bream, whereas comparatively enriched, indicating latter not contributor biomass species. However, using site-specific regression approach, significant relationship revealed between algal carbon fish, suggesting contributed ~20% bream. similar amount. provided majority fish. contend likely remaining interpretation supported outcomes multiple analyses. Although previous studies aquatic webs Australia have emphasised high-quality basal resources, study indicates sources demonstrates need consider circumstances cause biota switch sources.