Feeding habits of larval rabbitfish, Siganus guttatus in the laboratory

Abstract

The feeding habits of Siganus guttatus larvae were determined in laboratory rearing studies at 23.8-30.3 degree C by examination of digestive tract contents of larvae given rotifers and/or brine shrimp. Larvae were initially fed on rotifers at a total length (TL) of 2.6 mm (day 2 from hatching), and on brine shrimp at 4.4 mm TL (day 12). A change in feeding habits, seen as the flexion point in the relationship between larval TL and maximum amount of prey, occurred at about 7.0-9.5 mm TL with rotifers as prey, and at 7.2 mm TL with brine shrimp. Higher preference for brine shrimp over rotifers was seen in larvae 8-9 mm TL and larger. These changes in habit coincided with the full osteological development of the feeding apparatus in larvae at 7-8 mm TL. S. guttatus larvae exhibited a diurnal feeding pattern at day 9 (mean 3.7 mm TL), day 15 (5.8 mm TL) and day 21 (7.9 mm TL).