Apoptosis in the digestive tract of herbivorous Rana pipiens larvae and carnivorous Ceratophrys ornata larvae: an immunohistochemical study.

The lifespan of herbivorous Rana pipiens larvae is ∼3 months, while that of carnivorous Ceratophrys ornata larvae is only about 2 weeks. During metamorphic climax, the larval gut shortens dramatically, especially in R. pipiens, and its luminal epithelium is replaced by adult-type epithelium.