Effects of Three Different Diets on Survival and Growth of Larvae of the African Clawed Frog Xenopus laevis

Abstract

The African clawed frog Xenopus laevis has economic value in research, education, and the pet trade and has considerable potential for human consumption. In spite of its importance, little experimental research has been conducted on rearing techniques, particularly on diets. This study reports the survival and growth (in weight) of larvae reared on three diets: Purina Trout Chow, Purina Catfish Cage Chow, and a mostly grain-derived diet, referred to as experimental diet A. Twelve aquaria (37.9 L) were used with four replicates per diet. Forty newly hatched larvae were placed in each aquarium and fed ad libitum. The experiment was terminated when several larvae developed front legs, which indicated the onset of metamorphosis and feeding cessation. Larvae were sacrificed by treatment with tricaine methanesulfonate (MS-222), freeze-dried, and individually weighed to the nearest 0.1 mg. Survival was not significantly different (chi-square test) among the aquaria, but weights of larvae were significantly different (Kruskal–Wallis and Mann–Whitney U-tests); the trout chow produced the heaviest larvae, and experimental diet A produced the lightest larvae. The high crude protein content (60.7%) and large amount of animal-derived ingredients of the trout chow may have been responsible for the higher weights attained than with the two other diets.