Larvae to adult: skin ontogeny of Physalaemus ephippifer (Anura: Leptodactylidae)

Abstract

Throughout metamorphic development until adulthood, amphibians have important integumentary adaptations that maintain their physiological needs and protection against predation. The evolution of these strategies in the subfamily Leiuperinae has been elucidated in recent years. Therefore, the knowledge about Physalaemus ephippifer's skin attributes can corroborate the changes of these characteristics in the clade. The aim of this study was to assess the characteristics of P. ephippifer regarding the morphological development the skin during their lifespan. We collected foam nests in temporary ponds as well as adult individuals in a forest fragment. In the laboratory, the animals were classi ed by stage development, euthanized, and xed. Sections of the dorsolateral, lumbar, and femoral portions were dissected from the adult individuals. Samples were submitted to histological processing for light microscopy and scanning electron microscopy. In premetamorphosis phase, gland development is absent and secretory cells are present. In prometamorphosis, development of rst glandular rudiments without secretion production begins, also xanthophores. During metamorphosis, mucous glands differentiated before serous glands. Until late metamorphosis ciliated cells persist and epidermis changes to an adultlike. In adults, serous glands show polymorphism with different distributions in the body, despite not having macroglandular structures. In addition, P. ephippifer individuals have few epidermal projections and cryptic coloration. Our results show that despite sharing few morphological structures with other specimens of Leiuperinae subfamily, the characteristics present in individuals of P. ephippifer are appropriate to the niche occupied and consistent with the changes that occur throughout their lineage.