Abundance and distribution of fish larvae in the channel area of the Patos Lagoon Estuary, Brazil

Abstract

Distribution and abundance of fish larvae in the channel area of the Patos Lagoon, Brazil are reported. The Patos Lagoon is a shallow coastal lagoon with a very narrow connection with the Atlantic Ocean. Its southernmost region, characterized by a very dynamic estuary, was the site of 32 ichthyoplankton surveys conducted at 5 stations from April 1981 to March 1983. Samples were taken at 3 depth levels (surface, mid-water and bottom) and results indicated that larval density and distribution were associated with temperature. Larvae occurred year round and at all stations, but were most abundant and diverse during spring and summer with mean densities of 61/100 m3 and 189/100 m3 , respectively. However, this distribution was sometimes altered by meteorological conditions prevailing in the estuary. Twenty families of fishes were represented, including 27 taxa, 19 of which were identified to species. The three most abundant taxa overall were Mieropogonias fumieri, Brevoortia peetinata, and Lyeengraulis sp., whose larvae accounted for 22.9, 22.6, and 20% of the total, respectively. Parapimelodus valeneiennis; Blennidae; Triehiurus lepturus; Gobiesox strumosus; Paralonehurus brasiliensis; Maerodon aneylodon; Paraliehthys sp.; Atherinidae; Gobiosoma parri; and Mentieirrhus spp. had relative abundances between 1 and 5%.