Molecular identification, description, and phylogenetic implications of the tadpoles of 11 species of Malagasy treefrogs, genus Boophis

Abstract

Based on specimens identified by DNA barcoding, we describe the tadpoles of 11 species of treefrogs (Boophis) in the Malagasy family Mantellidae. All tadpoles belong to species of the stream‐breeding clade within Boophis. Based on these and other published descriptions of Boophis tadpoles which develop in running water bodies, we tentatively distinguish three ecomorphological guilds for these larvae. Guild A, in which we describe the larvae of B. boehmei, B. reticulatus, B. pyrrhus, B. tasymena, and B. viridis which have few lotic adaptations, their oral disc width being 31–43% of body width, with a single row of 48–81 marginal papillae, and the first upper keratodont row having 58–144 keratodonts. Guild B, in which we describe the tadpoles of B. albilabris, B. madagascariensis, B. luteus, and of an undescribed species here named B. sp. aff. elenae, is intermediate, with an enlarged oral disc, an increasing number of keratodont rows and a lower height of the caudal fin. In these tadpoles, oral disc width is 43–63% of body width, they have one or two rows of 69–164 marginal papillae, and the first upper keratodont row has 164–238 keratodonts. Guild C contains tadpoles with a very large oral disc, living on submerged rocks and stones in stream sections of strong current. In this guild we describe the tadpoles of B. marojezensis and B. sibilans. Their oral disc width is 63–89% of body width, there are multiple rows of many marginal papillae, and the first upper keratodont row has many small keratodonts which are difficult to count, but consistently amount to over 200. In B. marojezensis, the dorsal gap in the marginal papillae rows, apparent in all other species, is closed. These larval morphologies show a rather good fit with recently published molecular phylogenetic data: species groups that were confirmed to be monophyletic in most cases have similar larval morphologies, and, in contrast, where species of the same group have disparate larval morphologies the monophyly of the group is questionable (e.g. the B. majori group). Nevertheless, some cases of convergent evolution are apparent, such as the highly specialized Guild C morphology, which may have evolved separately in the B. albipunctatus group, B. mandraka group, and in some species of the B. majori group.