Reductions in the length of typhlosole and the small intestine of premetamorphic <i>X. laevis</i> and <i>X. tropicalis</i> tadpoles upon T3 treatment.

<p>Stage 54 <i>X. laevis</i> or <i>tropicalis</i> tadpoles were treated with 10 nM T3 at 18°C (<i>Xenopus laevis</i> tadpoles) or 25°C (<i>Xenopus tropicalis</i> tadpoles) for the indicated days and the intestine was isolated. The length of the typhlosole and the small intestine were measured. Note that the lengths of the intestine was reduced upon T3 treatment and that after 4–5 days of treatment, the typhlosole was no longer identifiable due to metamorphic changes in the intestine, resembling that at the climax of metamorphosis. The faster changes for <i>X. tropicalis</i> tadpoles were in part due to the higher temperature at which the animals needed to be reared.