Filling Gap and Geographic Distribution Map of Elachistocleis helianneae Caramaschi, 2010 (Amphibia: Anura: Microhylidae)

Abstract

The genus Elachistocleis comprises fossorial frogs distributed throughout Central and South America. Despite their wide distribution, species such as Elachistocleis helianneae Caramaschi, 2010 (Anura: Microhylidae) are poorly documented due to their cryptic behaviour. Here, we present the first record of E. helianneae for the western region of Pará state, in the central Brazilian Amazon. Four specimens (one juvenile and three adults) were collected during nocturnal surveys in temporary puddles along the BR-163 highway between March and April 2022. Additionally, an updated distribution map of the species was created, incorporating this new record and data available in the literature. The new record fills a significant gap in the distribution of E. helianneae in the central Amazon, which previously spanned over a thousand kilometres. Our record is located approximately 590 km from the closest record to the west, in the state of Amazonas, and about 520 km from the nearest record to the east, in the state of Amapá. The Santarém record significantly improves our understanding of the distribution of E. helianneae, emphasising the importance of targeted surveys in underexplored habitats. Our findings highlight the importance of filling distributional gaps to enhance knowledge of amphibian biodiversity and inform conservation efforts.