Response of Red Drum Larvae to Graded Levels of Menhaden Oil in Semipurified Microparticulate Diets

Larvae of red drum (Sciaenops ocellatus) were reared from first feeding to 18 d posthatching at 26°C under a feeding protocol that combined artificial diets with live food (rotifers). Semipurified microparticulate test diets were formulated with graded levels (13.0, 18.3, 22.7, and 27.1 %) of total lipid (menhaden oil and red drum muscle lipid). Growth of larvae fed the test diets was compared with that of larvae fed a commercial microparticulate diet (Kyowa-A) containing 24.8% crude lipid. In separate, repeated feeding trials, standard length and dry weight of 18-d-old larvae fed the Kyowa-A diet were significantly greater than lengths and weights of larvae fed the test diets. However, dry weight of larvae fed the diet containing 18.3% total lipid was significantly greater than weights of larvae fed the other test diets. Additionally, the semipurified diets were readily accepted and ingested by larvae. Digestion of the diets was evident in the significant growth of the larvae.