Reproductive strategies, free-swimming tadpoles, and natural history of the Santa Marta rocket frog “Colostethus” ruthveni Kaplan, 1997 (Anura: Dendrobatidae), with a review of the distribution of larval and reproductive characters in Dendrobatoidea

Abstract

Abstract Herein, we research several aspects of biology of the Santa Marta rocket frog “Colostethus” ruthveni from the Sierra Nevada de Santa Marta, Colombian Caribbean. Quantification of relative abundance and habitat use was provided. Likewise, free-swimming tadpoles and reproductive strategies were described. In addition, the distribution of larval and reproductive characters across Dendrobatoidea were examined as an approach for their evolution and to identify whether these can complement the diagnosis of the “C.” ruthveni group. We recorded 853 specimens of “C.” ruthveni in six localities, resulting in a fairly high relative abundance at each site. Leaf-litter and rocks were the most used substrata, although their proportion of uses varying across the sites. The external morphology of free-swimming tadpoles of “C.” ruthveni resembles the former members of the Colostethus sensu lato. The courtship is a complex interaction of acoustic, visual, and tactile displays, which leads to the cephalic amplexus. "Colostethus" ruthveni showed wide variation in oviposition sites, including natural and artificial substrates at ground level, as well as creeping vegetation above the ground or water. Therefore, we consider that the species exhibits multiple reproductive modes, one of them previously unknown for anurans. Several larval and reproductive characters of “C.” ruthveni consist of a compendium of ancestral states. However, some characters are of special interest because these could be considered reversions to ancestral states or apomorphies, which could constitute synapomorphies of the “C.” ruthveni group if demonstrated to occur in the other undescribed members of the complex. In addition, we evidenced that "C." ruthveni is the only Dendrobatine with considerably narrow A2-gap. All this information on morphology and natural history provides insight into the evolutionary processes of poison frogs and provides basic information necessary for the management of this potentially endangered species.