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

Abstract

Corythomantis greeningi is a casque-headed frog that occurs in xeric and sub-humid regions of northeastern Brazil. Individuals are often found on rocks on banks of temporary streams or in ponds upon “lajedos”. Suctorial tadpoles are often found clasping to the rocks in the streams so as not to be dragged by the current; therefore, they have modified external and internal morphology. Here, we describe the internal oral anatomy and the chondrocranium of the tadpole of C. greeningi and compare it to the available descriptions of Lophyohylinae and other suctorial tadpoles. The internal oral morphology in C. greeningi resembles pond-dwelling casque-headed frogs, although it has been found in temporary lotic environments. Corythomantis greeningi has unusual chondrocranial morphology relative to that of other described Lophyohylinae, including marked differences at the cornua trabeculae and palatoquadrate. Apparently, the chondrocranial morphology is related to its ecomorphology, because it is structurally more similar to other suctorial tadpoles that inhabit lotic environments than to phylogenetically related species such as Trachycephalus typhonius and Phyllodytes gyrinaethes

Differences in external, internal oral and chondrocranial morphology of the tadpole ofCorythomantis greeningiBoulenger, 1896 (Anura: Hylidae)

“…tadpoles. 1 -Municipality of Pedro II, state of Piauí (present study); 2 -Barreiras (Oliveira et al, 2017), 3 -Morro do Chapéu and 4 -Feira de Santana (Juncá et al, 2008), state of Bahia.…”

“…greeningi (Oliveira et al, 2017), N. brunoi (Wogel et al, 2006), N. siemersi (Cajade et al, 2010), O. oophagus, O. taurinus, Os. septentrionalis (Schiesari et al, 1996), Os.…”

“…Internal oral anatomy terminology followed Wassersug (1976 and1980) and Wassersug and Heyer (1988). Chondrocranium description was based on four tadpoles in stages 34 and 36 (CBPII 112), following Cannatella (1999), Haas (2003), Nascimento (2013), and Oliveira et al (2017). The specimens were cleared and stained using the Taylor and Van Dyke (1985) technique with modifications.…”

“…The specimens were cleared and stained using the Taylor and Van Dyke (1985) technique with modifications. Chondrocranial terminology followed Larson and de Sá (1998), Cannatella (1999), and Oliveira et al (2017).…”

“…Previous studies have described the external morphology of C. greeningi larvae, based on specimens collected in the municipalities of Feira de Santana and Morro do Chapéu (Juncá et al, 2008), and internal oral anatomy and chondrocranium, from specimens collected in Barreira municipality, all in the state of Bahia (Oliveira et al, 2017) (Fig.1). However, we observed some differences in tadpoles collected in temporary streams in the northern region of the state of Piauí.…”