The contribution of microphytobenthos for scallop Euvola ziczac (Bivalvia: Pectinidae) feeding in a shallow area of the south-eastern Brazilian continental shelf

Abstract

The general composition and abundance of microalgae in sediment, water column and stomach contents of scallops were studied at two Euvola ziczac beds on the south-eastern inner Brazilian continental shelf. These areas, which support an extensive demersal fishery, are hydrologically dominated by Tropical and Subantarctic Waters and exhibit a summer water intrusion of South Atlantic Central Water (SACW). The same genera of benthic diatoms, mainly <30 μmm, were found on sediment and scallop stomach samples. Despite the seasonal variation of hydrographic conditions, the composition and abundance of main benthic diatoms from sediment and stomachs did not change throughout the year. On the other hand, phytoplankton from the water samples collected above the seabed (mainly pelagic diatoms >30 μm and dinoflagellates) was composed of distinct taxa and presented a high seasonal variation in abundance. The prevalence of microphytobenthos in the scallop diet suggests the importance of this community to the sustainability of this valuable demersal fishery resource.