Distinctions in the diets and distributions of larval tunas and the important role of appendicularians

• DOI: 10.4319/lo.2010.55.3.0983
• Publication Date: 2010-03-07T04:55:22Z
• Authors: Joel K. Llopiz; David E. Richardson; Akihiro Shiroza; Sharon L. Smith; Robert K. Cowen
• Keywords: Skipjack tuna; Thunnus; Scombridae; Ichthyoplankton

Monthly plankton sampling across the Straits of Florida (SOF) allowed for a thorough investigation feeding ecologies four taxa larval tunas (family Scombridae, tribe Thunnini) and horizontal vertical distributions tuna larvae their dominant prey. Before piscivory, Thunnus spp. had mixed diet crustaceans appendicularians, whereas skipjack ( Katsuwonus pelamis ), little tunny Euthynnus alletteratus Auxis displayed highly selective nearly exclusive on appendicularians. The availability both appendicularians fish prey declined from west to east SOF, were notably patchy. In western SOF where was more abundant, all co‐occurred, indicating sharing resources by larvae, in addition adults these using similar spawning habitat upstream Current. central eastern less only two exhibited significantly different distributions. Prey removal rates (estimated gut evacuation daily rations) occurring co‐occurred are likely be sustainable appendicularian levels within this region but would potentially not east. spatial trophic characteristics abundant highlight potential influence feeding‐related processes adult behavior, while also illustrating critical link microbial food web provided oligotrophic environment.