Supplementary description of Boulenophrys elongata (Anura, Megophryidae): Sexual dimorphism and observations on reproductive behaviours.

Abstract

Background: The genus Boulenophrys displays high species diversity, yet most species are known only from isolated localities with narrow geographic distributions. Fundamental ecological data and reproductive traits remain largely undocumented across the genus. Boulenophrys elongata is one of the least investigated species in this group. Given that the male type specimens of this species exhibited incompletely developed breeding-related secondary sexual characteristics, the sexual dimorphism of the species has remained poorly clarified.

New information: We conducted systematic field surveys at the type locality of Boulenophrys elongata and collected five adult individuals during the breeding season, enabling supplementation of morphological diagnoses and baseline ecological data. Through long-term in situ monitoring, we recorded the full sequence of pre-amplexus reproductive behaviour, constituting the first formal documentation of such behaviour in the genus. This study addresses critical gaps in the biological understanding of B. elongata and the genus and provides empirical support for population assessments and conservation strategies for montane amphibians.