Larval development of hoplias cf. Lacerdae (Pisces: Erythrinidae) and delayed initial feeding effects

Abstract

Larval development of Hoplias cf. lacerdae was studied under laboratory conditions. After hatching, ontogenetic changes were recorded on food-deprived larvae in 12-hour intervals. Mouth opening occurred after 2.5 days and notochord terminated flexure in 6.5 days. Notochord length increased at a constant rate until complete yolk absorption (13,5 days). Larval dry weight and body height diminished gradually up to 21 days after hatching, when all starved larvae died. Every 12 hours after yolk absorption, groups of larvae (n=15), were separeted, and fed with Artemia nauplii for 10 days. The point- of-no-return (when 50% of larvae were unable to feed or to assimilate ingested food after delayed feeding), was not apparent in this species.