Abstract
We describe the tadpole morphology of four species of frogs classified in the endemic Madagascan subgenus Brygoomantis of the genus Mantidactylus, based on larval specimens identified by DNA barcoding: Mantidactylus betsileanus and M. biporus, and two so far undescribed species that are here named M. sp. aff. betsileanus "very slow calls" and "Vohidrazana" referring to their bioacoustic features or collecting locality. The tadpoles of these four species are brown to yellowish benthic forms with a depressed body shape, dorsally directed eyes and relatively low fins. The oral discs are generalised and all species exhibit a wide gap in dorsal papillae. There is variation among different developmental stages with regard to the keratodont row formulae. In Mantidactylus betsileanus, younger stages (25 and 26) exhibit the formula 1:3+3/1+1:2, whereas it is 1:4+4/1+1:2 in older stages (36 and 38). In M. sp. aff. betsileanus "very slow calls", keratodont row formulae vary within one developmental stage (25–26) from 1:3+3/3 to 1:4+4/3, whereas it seems to be constantly 1:4+4/3 in all examined developmental stages of M. sp. aff. betsileanus "Vohidrazana". In general, the larvae of the different Brygoomantis species studied are morphologically similar to each other. Differences between species mainly concern colouration, shape of body and the number of keratodonts per millimetre, which is approximately 38 in M. betsileanus, 50 in M. biporus, and 60 in the two undescribed species.References
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