Diversity of the strongly rheophilous tadpoles of Malagasy tree frogs, genus Boophis (Anura, Mantellidae), and identification of new candidate species via larval DNA sequence and morphology

Abstract

This study provides detailed morphological descriptions of previously unknown tadpoles of the treefrog genus Boophis Tschudi and analyses of habitat preferences of several of these tadpoles in Ranomafana National Park. A total of twenty-two tadpoles determined via DNA barcoding are characterized morphologically herein, fourteen of them for the first time. Twelve of these tadpoles belong to taxonomically undescribed candidate species which in several cases are so far only known from their larval stages. Our data show that the larvae of some of these candidate species occur syntopically yet maintaining a clearly correlated genetic and morphological identity, suggesting that they indeed are true biological and evolutionary species. Tadpoles considered to belong to the “adherent” ecomorphological guild inhabit fast-running waters and their oral disc is commonly to continuously attached to the rocky substrate, supposedly to keep their position in the water current. Some of these species are characterized by the presence of a dorsal gap of papillae and the absence of an upper jaw sheath. This guild includes the tadpoles of the Boophis albipuncatus group ( Boophis ankaratra , Boophis schuboeae , Boophis albipunctatus , Boophis sibilans , Boophis luciae ), and of the Boophis mandraka group ( Boophis sambirano and six candidate species related to this species and to Boophis mandraka ). Tadpoles considered belonging to the “suctorial” guild inhabit fast-running waters where they use frequently their oral disc to attach to the substrate. They have an enlarged oral disc without any dorsal gap, including two nominal species ( Boophis marojezensis , Boophis vittatus ), and five candidate species related to Boophis marojezensis . An ecological analysis of the tadpoles of Boophis luciae , Boophis schuboeae and Boophis marojezensis [Ca51 JQ518198] from Ranomafana National Park did not provide evidence for a clear preference of these tadpoles to the fast flowing microhabitat sections of the stream, although the tadpoles discussed in this study are typically caught in this habitat.

DNA barcoding Madagascar’s amphibian fauna

“…In the meantime, about 32 of these have been formally described as new species, or resurrected from synonymy (e.g., Glaw et al, 2010;Köhler et al, 2010;Vences et al, 2010), and additional species have been newly discovered and described; the number of nominal species of native amphibians in Madagascar has consequently risen to 292. During this same time, various studies have revealed 22 additional, previously unknown genetic lineages qualifying as candidate species: one Anodonthyla , one Stumpffia , one Blommersia, two Boophis and one Guibemantis (Gehring et al, 2010), four Mantidactylus (Randrianiaina et al, 2011), and 12 Boophis (Randrianiaina et al, 2012). The COI data herein, mostly from our own expeditions into northern Madagascar (Makira and Tsaratanana areas) in 2009 and 2010, provide evidence for the presence of at least 14 further candidate species with divergences to nominal taxa above the threshold of 6% uncorrected pairwise COI distance (further discoveries from two other surveys in 2010 and 2012 are not yet analyzed): two Boophis, two Cophyla, one Gephyromantis, one Guibemantis, three Rhombophryne, two Spinomantis and three Stumpfßa.…”

Opposing Patterns of Seasonal Change in Functional and Phylogenetic Diversity of Tadpole Assemblages

“…In Madagascan tadpoles, some closely related groups indeed show a broader range of traits than others which is not necessarily linked to their species richness (e.g., [ 80 – 82 ]). There are several accounts of homoplasy in morpho-functional traits in Madagascan tadpoles [ 83 ] although in general, tadpole morphology largely fits phylogeny ([ 84 ] and references cited above). As the mentioned exceptions are randomly distributed between the taxonomic groups included in this study, they may not necessarily have influenced the results.…”

The anatomy and structural connectivity of the abdominal sucker in the tadpoles of Huia cavitympanum , with comparisons to Meristogenys jerboa (Lissamphibia: Anura: Ranidae)

“…Suctorial tadpoles of various frog lineages have conquered torrential habitats independently (Gradwell 1973;Altig and Johnston 1989;McCranie et al 1989;Haas and Richards 1998;McDiarmid and Altig 1999;Coloma 2002;Matsui et al 2005;Pramuk and Lehr 2005;Shimada et al 2011;Randrianiaina et al 2012;Zachariah et al 2012). These suctorial tadpoles have evolved certain morphological features convergently.…”