Vertical distribution and the role of physical processes in the feeding dynamics of two larval sciaenids Sciaenops ocellatus and Cynoscion nebulosus

摘要: Red drum Sciaenops ocellatus and spotted seatrout Cynoscion nebulosus larvae were collected using plankton benthic-sled tows every 2 h for 26 on 4 separate dates in late August to early October 1990 Aransas Bay, Texas, USA. Gut contents gut fullness evaluated determine if feeding was randomly distributed over depth time, compare between the species. Calanoid copepods dominant prey all size- classes of red larvae. Copepod nauplii, bivalve barnacle important small drum, while calanoid copepods, dinoflagellates soft-bodied organisms diets large most food items seatrout; gastropod veligers copepod nauplii also prey. Gape size positively correlated with standard length both Mean increased gape width but there wide variation at any given width. Small ( 4.5 mm) fish had distinct diets. Similar numbers surface bottom waters (6 m) during night, day more waters. Larvae species fed primarily daylight hours. Feeding extended later evening than drum. There no significant relationship current speed or very successful under conditions little indication that vertical distribution associated success. Transit periods through well-mixed tidal inlets may provide excellent opportunities, as well a route transport essential nursery habitats.