A Developmental Staging Table for Physalaemus biligonigerus (Cope, 1861) (Anura: Leptodactylidae)

CHULIVER PEREYRA, MARIANA; FABREZI, MARISSA

South American Journal of Hepetology

Brazilian Society of Herpetology

Año: 2019 vol. 14 p. 150 - 161

1808-9798

Physalaemus biligonigerus is a leptodactylid frog that is widely distributed in southern South America and a common member ofanuran assemblages that breed in temporary ponds near human settlements. Herein, we analyzed its embryonic and larval morphologythrough the completion of metamorphosis and constructed a normal table of development. In addition, the timing of development andgrowth data are provided. Development of P. biligonigerus from fertilization through metamorphosis takes 20?24 days. We recognized 46discrete developmental stages on the basis of readily discerned, unambiguous, external traits that can be identified in preserved specimens.In contrast with the standard Gosner developmental table, we recognized several particularities in the development of this species. Thestaging criterion based on external gill morphology presented here is a novel approach to distinguish pre- and post-hatching stages, whichcould also be employed in other anuran species. We found that anal tube loss in P. biligonigerus occurs earlier than Gosner Stage 41; this traitis highly variable among species and should not be used as a standard criterion. Our analysis demonstrates the value of detailed specificstaging tables to characterize anuran life cycles. Furthermore, we point out that the use of generalized standard tables might mask therichness of phenotypic variation during the ontogeny of anuran species.