Fig. 1

Experimental design and T3-driven metamorphic climax. a Experimental design. b–g T3-induced morphological and physiological changes in pro-metamorphic R. omeimontis tadpoles (stages 30–31). T3-treated tadpoles had reduced food intake (b), reduced body weight (c), accelerated development of hind limbs (d), shortened tail (e), broadened oral disk width (f–g), and reduced mobilization of hepatic resources (f–g; reflected by the liver size and morphology). Food intake was reflected by the residual content of spirulina powder in the water; the higher content of the spirulina powder, the darker the green color of the water. p < 0.001