Difference in Larval Food Habit of Two Japanese Rana Species

ABSTRACT

Suitability of different food items for tadpoles of two Japanese Rana species (R. japonica and R. ornativentris) showing different distributional patterns, was studied in a laboratory rearing experiment. Tadpoles were individually fed single food items (leaf litter, algae, or sludgeworms), and their survival, growth, and development were compared. Algae-fed R. japonica tadpoles metamorphosed sooner and at a larger size than worm-fed ones, while R. ornativentris demonstrated the opposite. No litter-fed tadpoles metamorphosed, but R. ornativentris showed higher survival and more developlnent than R. japonica. Their different food habits may be related to their distributional patterns.