Embryonic ontogeny of three species of Horned frogs, with a review of early development in Ceratophryidae

GROSSO, JIMENA RENEÉ; BALDO, DIEGO; SALGADO COSTA, CAROLINA; NATALE, GUILLERMO

JOURNAL OF MORPHOLOGY

WILEY-LISS, DIV JOHN WILEY & SONS INC

Lugar: New York; Año: 2019

0362-2525

Horned frogs of the family Ceratophryidae are a conspicuous anuran group that includes three genera endemic to South America. Most ceratophryids inhabit semiarid environments, but three species of Ceratophrys occupy tropical or temperate humid areas. Several morphological and behavioral characters of larvae and adults are conserved across the family. In this work, the embryonic development of C. ornata, C. cranwelli, and the monotypic genus Chacophrys are described and compared with that of species of Lepidobatrachus, based on examination of specimens and accounts in the literature. Ceratophryid embryos share a suite of morphological features and heterochronic shifts during development. Most of them, such as gill structure, ciliation, early hatching, and precocious differentiation of gut and hind limbs, are shared by all the species regardless the differences in the habitats that occupy. This is consistent with previous observations in some adult characters, and likely supports the hypothesis of an early diversification of ceratophryids in semiarid environments. Other embryonic features, such as the morphology and ontogeny of the oral disc and digestive tract, present a wide variation in the family correlated with tadpole feeding habits. Lastly, some conserved (gastrulation pattern, Type A adhesive glands) and other taxon-specific features (nasal appendix) pose further ecological and historical questions to be explored in the group.