Interference Competition Among Larval African Clawed Frogs, Xenopus laevis, Necessitates Removal of Bottom Debris to Promote Growth

ABSTRACT

Survival and growth of larva! African clawed frogs, Xenopus laevis, are reported under two experimental environments. Ten aquaria (37.9 L) were used, with five replicates each of two experimental environments (bottom debris intact and bottom debris removed by siphoning). Forty-five newly hatched larvae were placed in each aquarium and fed ad libitum. When a few larvae developed front legs, the experiment was terminated. Larvae were sacrificed, freeze-dried, and individually weighed (nearest 0.1 mg). Survival was not significantly different among cohorts (P> 0.10), but larval weights were significantly different (P<0.00001). Larvae from aquaria with their bottom debris removed (mean = 34.5 mg) were nearly four times heavier than larvae from aquaria with their bottom debris intact (mean = 8.8 mg). This suggests that bottom debris, and/or aquarium water, contained factors that retarded growth. To promote maximum larval growth and reduce interference competition, bottom debris must be periodically removed and siphoned water replaced with fresh, aged water.