Journal of Aquaculture Research & Development

Impact of an invasive bivalve in the diet of commercial and sport valuable fish larvae species in a eutrophic subtropical reservoir

4^th International Conference on Fisheries & Aquaculture

November 28-30, 2016 San Antonio, USA

Esteban M Paolucci, Leila Ron, Daniel H Cataldo and Demetrio Boltovskoy

Museo Argentino de Ciencias Naturales Bernardino Rivadavia, Argentina

Posters & Accepted Abstracts: J Aquac Res Development

Abstract:

Major factors affecting riverine larval fish development include food availability and larval fish ability to capture and ingest food items. In this context, invasive species and river impoundments have important and complex impacts on early fish larvae stages. Using fish larvae samples collected in large rivers and in a reservoir (Salto Grande reservoir, Argentina-Uruguay), periodically affected by very strong cyanobacterial blooms, we studied the impact of the larvae of the exotic bivalve Limnoperna fortunei on the diet of larval fish. Compared with other nearby lotic waterbodies, the abundance of fish larvae in general, and of feeding fish larvae in particular, were scarcer in the reservoir, especially during algal bloom periods, which generally coincide with peaks in larval fish production. Of the 245 larval fish with gut contents, L. fortunei veligers were found in only 20% of the larvae. Seven fish taxa (out of a total of 12) consumed veligers of L. fortunei, but only two showed a preference for this prey over other food items. Changes in the species composition of larval fish assemblages due to the river impoundment, and temporal uncoupling between ichthyoplankton and veliger densities due to the toxigenic effects of Microcystis spp. on Limnoperna veligers are concluded to account for the comparatively low importance of the invasive bivalve's veligers in the diet of native larval fish. These results reflect the complexity of the interactions brought about by an invasive species, underscoring the assumption that the impacts of biological invasions depend as much on the invader, as on the regional and environmental settings of the ecosystem invaded.

Biography :

Email: estebanmpaolucci@gmail.com