Parental care and skin feeding in the caecilian Siphonops annulatus: an integrative approach

Abstract

Caecilians (order Gymnophiona) are apodan, serpentiform amphibians, distributed in most of the tropical regions of the planet. Due to the generally fossorial habit, the caecilians constitute the least known group of tetrapods in all biological aspects. As in other amphibians, their skin is rich in glands that secrete a variety of chemical substances that participate in several vital activities, such as cutaneous respiration, reproduction and defence against predators and microorganisms. The research group of the Cell Biology Laboratory of Instituto Butantan, participating of an international team, discovered a peculiar phenomenon related to parental care. This finding, published in 2006 (Nature, 440, 926-929), was considered by Marvalee Wake as "perhaps the most dramatic new discovery in caecilian biology." This article demonstrated that the young oviparous caecilians, during parental care, feed exclusively on the mother's skin. Although described more than a decade ago, the biology, morphology, biochemistry and molecular biology related to this phenomenon remain little elucidated. For example, it is possible that the composition of secretions and the morphology of the cutaneous glands change during parental care. It is also possible that the secretions contain molecules that are important for the nutrition and immunity of the young, similar to the breast milk in mammals. This project, therefore, aims at the study of the oviparous caecilian Siphonops annulatus as a model of parental care and skin feeding, using an interdisciplinary approach based on morphological, biochemical and molecular biology techniques.