Embryonic morphology in five species of Hypsiboas (Anura: Hylidae)

作者：Navarro Acosta Grisel; Baldo Diego; Kolenc Francisco; Borteiro Claudio; Vera Candioti Florencia

来源：The Herpetological Journal, 2017, 27(2): 121-132.

• adhesive glands
• ciliation
• external gills
• hatching gland
• oral disc

Research concerning the early development of anuran tadpoles has sparked new interest, ever since comparative studies revealed structural and temporal variations of embryonic stages within different taxonomic groups. In this paper we studied the early ontogeny of five species of the hylid genus Hypsiboas: H. curupi, H. pulchellus, H. riojanus and H. sp. from the H. pulchellus group, and H. faber from the homonymous group. We analyse the development of typical larval structures (oral disc), and of embryonic transient structures (external gills, ciliated cells, hatching glands and adhesive glands). The diversity in structural patterns is mainly related to the number and size of external gills, size of the adhesive glands, ciliation density and number of labial tooth ridges. In turn, heterochronic shifts mostly concern the time of adhesive gland division, and the regression of the hatching gland and ciliated cells. In some cases these variations appear to be related with oviposition sites and environments where embryos and larvae develop. Hypsiboas faber embryos, which develop in small nests outside water bodies, exhibit the largest hatching gland and large, densely ciliated and highly branched external gills as a possible response to low oxygen environments. The large and persistent adhesive glands of H. curupi and H. sp. gr. pulchellus might be related to the development of embryos and larvae in small streams. Within the same intrageneric group, certain embryonic traits of H. pulchellus (e.g., tooth row formula 2/3, minute external gills, low body ciliation) appear to be paedomorphic regarding ancestral ontogenies, but the ecological/functional correlation (if any) of these features is uncertain.

• 出版日期2017-4