Food consumption of fish in a sub-tropical SW Atlantic ecosystem off Brazil: comparison of four Sciaenid species

The first evaluations of the daily ration and population food consumption of four Sciaenid fish, under natural conditions for the Brazilian south-western Atlantic shelf (23°35′S, 45°00′W) are presented. The average daily ration ranged from 4.38 to 12.92 % body mass (90% confidence interval) for the juvenile shortfin corvina (Isopisthus parvipinnis), from 0.41 to 5.52 % body mass (90% confidence interval) for the juvenile shorthead drum (Larimus breviceps) and from 3.14% to 3.15% body mass for the juvenile whitemouth croacker (Micropogonias furnieri). Juveniles of the banded croacker (Paralonchurus brasiliensis) showed higher estimates (2.58–2.60% body mass) than those for the adults (1.2–1.84% body mass). The mean food consumption rate of the population was estimated at about 11 and 8 year^–1, respectively, for the whitemouth croacker, and banded croacker, corresponding to a gross efficiency of 13 and 10%. The estimates of daily ration were related to the feeding habits as well as to size of the fish, and probably to their specific energy budget. Estimates of population food consumption are related to population structure.