Difference in living environments, morphology, and physiology between cave and outside tadpoles; (A–B) typical microhabitats and morphology of O. rhodostigmatus tadpoles; (C) developmental stages of O. rhodostigmatus tadpoles; (D–G) changes in tadpoles’ body weight, body length, gut length, and relative gut length (gut length/body length) across environments and developmental stages; note that the gut length also decreased drastically from Gosner Stages 40–42; this was due to the onset of metamorphic climax at Stage 42; different letters in panel D–F indicate significant differences between stages for cave or outside individuals (simple effect analysis for ANOVA, with significant interactive effect); different letters in panel G indicate significant differences between stages for all individuals (two-way ANOVA followed by the S-N-K post-hoc test, without a significant interactive effect); asterisks indicate differences between cave and outside individuals at specific stages (simple effect analysis for ANOVA, with significant interactive effects): ^*P < .05; ^**P < .01; ^***P < .001.