Normal Development of Microhyla ornata: The First Description of the Complete Embryonic and Larval Stages for the Microhylid Frogs (Amphibia: Anura)

Abstract

Developmental changes in external morphological characters were examined for the whole embryonic-larval period of Microhyla ornata from Okinawajima Island, Ryukyu Archipelago, Japan. By considering the extent of morphological changes observed and compatibility with standard developmental tables hitherto proposed for other anuran groups, a developmental table consisting of 45 developmental stages was proposed for this species. Eight developmental terms, each consisting of several successive stages, were also defined-Cleavage-Blastula [stages 1-10], Gastrula [stages 11-14], Neurula [stages 15-18], Tail bud [stages 19-21], External gill [stages 22-28], Hind limb bud [stages 29-33], Hind limb formation [stages 34-41], and Metamorphosis [stages 42-45]). From previously described conspecific samples from other localities, our sample exhibited appreciable differences in the egg diameter, timing of pigmentaion at the position of the stomodium, and a few other tadpole characters. © 2003, The Herpetological Society of Japan. All rights reserved.