Is a dwarf population of Corythomantis greeningi Boulenger, 1896 (Anura, Hylidae) a new species?

Abstract

We studied the possible existence of a new dwarf species of the monotypic genus Corythomantis, based on tadpole morphology and advertisement call characteristics of two populations from State of Bahia: Serra São José (dwarf adults) and Lages (normal adult size). We compared the tadpole morphology and the advertisement call of Corythomantis greeningi from Lages with the population of Serra São José. We did not find any differences supporting that the population of Lages could represent a new species of Corythomantis. The tadpoles show external morphological characters associated with benthonic habitats and dental formula 5–6(1)/5–8. The advertisement call is composed of one pulsed note with duration of approximately 0.30 s and dominant frequency of approximately 1.00 kHz.

Chondrocranium and internal oral morphology of the tadpole of Corythomantis greeningi (Anura: Hylidae)

“…Corythomantis greeningi reproduces in temporary shallow rivers, which mainly form during the rainy season across wide bare stones locally named "lagedos". In this environment, males call among rock crevices and tadpoles can be observed in small ponds along the drying river bed, in lotic waters, or, frequently, clasping on the rocky river bed (Juncá et al 2008). Suctorial anuran larvae are highly specialized for discs as adhesive organs to attach to the substrate (Haas and Richards 1998).…”

“…Tadpoles of these species are characterized by a dorsoventrally originating posterior to the tail-body junction, undivided tooth rows, and a large, ventrally located oral disc with an uninterrupted outer row of oral papillae (Haas and Richards 1998). Some of these features are described for C. greeningi in Juncá et al (2008).…”

“…This population inhabits an area of seasonal forest in the Cerrado biome, predominant at this locality. Species with the available description in Juncá et al (2008) and by raising larvae in the laboratory through metamorphosis. Voucher specimens were preserved in 8% formalin and deposited in the herpetological collection of the Museu de Zoologia da Universidade Federal da Bahia (UFBA10612) and Universidade Federal do Maranhão (HUFMA2083-2085).…”

“…According to McDiarmid and Altig (1999), suctorial tadpoles are often found clasping rocks in streams so as not to be dragged by the current morphology. Juncá et al (2008) described and illustrated the external morphology of the larvae based on specimens from Serra São José and Lages, state of Bahia, Brazil. However, the internal oral anatomy and chondrocranial morphology is not known.…”

“…Corythomantis greeningi is distributed throughout Atlantic Forest and Caatinga morphoclimatic domains, in xeric and sub-humid regions of northeastern Brazil (Frost 2017). Individuals usually are found on vegetation, including in bromeliads, and frequently in rock outcrops near temporary streams (Juncá et al 2008, IUCN 2017.…”