The endotrophic nidicolous tadpole of Cycloramphus eleutherodactylus (Miranda-Ribeiro) (Anura: Cycloramphidae)

Abstract

Cycloramphus eleutherodactylus (Miranda-Ribeiro 1920) is a terrestrial species described from Paranapiacaba region, state of São Paulo. Sá et al. (2019) recovered the species as a complex in their molecular based phylogeny, congruent to previous observations based on morphology (Heyer 1983a; Verdade 2006; Matos 2011). It occurs in forests of mountainous areas in the states of Minas Gerais, Rio de Janeiro, São Paulo, and Paraná in southeastern and southern Brazil. We were fortunate to found an adult C. eleutherodactylus together with an egg clutch under a rock inside forest, at least 200 m far from the nearest water body, during a field trip to the Estação Biológica de Boracéia (EBB, 23°38’ S, 45°50’ W) in 2005. The EBB is approximately 50 km distant from Paranapiacaba in straight line (see Heyer et al. 1990 for detailed EBB collection history and habitat description, and Verdade et al. 2009 for the collection history in Paranapiacaba region). Herein we describe the tadpole of C. eleutherodactylus, and compare its morphology with other known Cyclorhamphidae tadpoles. Also, we briefly discuss the terrestrial reproduction and endotrophy in tadpoles of Neoaustrarana clade. It is the fourth nidicolous endotrophic tadpole to be described in Cycloramphus, the second belonging to core species as the other two were described as Zachaenus Cope, now a synonym of Cycloramphus (Dubois et al. 2021; Frost 2022).