Morphological variation in anurans of family Cycloramphidae and how it relates to environmental factors

• Grant number: 25/08101-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2025
• End date: August 31, 2026
• Field of knowledge: Biological Sciences - Zoology - Morphology of Recent Groups
• Principal Investigator: Vanessa Kruth Verdade
• Grantee: Caio Andrade Medina
• Host Institution: Centro de Ciências Naturais e Humanas (CCNH). Universidade Federal do ABC (UFABC). Santo André , SP, Brazil
• Associated research grant: 20/12658-4 - Challenges to the conservation of amphibians and squamate reptiles, with emphasis on the Brazilian fauna: from basic information to conservation actions, AP.BTA.TEM

Abstract

Climate change and its effects are widely covered in the media, as climate and other environmental variables directly and indirectly influence life forms. Part of this influence is reflected in the so-called ecogeographical rules, which explain morphological and physiological adaptations (e.g. Bergmann's Rule). However, these rules do not apply well to ectothermic animals, such as amphibians. The Cycloramphidae family, composed of the genera Thoropa and Cycloramphus, includes species mostly found in the Atlantic Forest, which can be divided into two ecomorphological groups: saxicolous and terrestrial. Morphology and reproductive modes vary between these groups, with saxicolous species appearing more restricted in terms of microhabitat. Despite these constraints, this group has a broader distribution than the terrestrial one, suggesting that environmental characteristics differentially affect these sets of species. To understand shape variation in Cycloramphidae and its relationship with environmental factors, we will use geometric morphometrics, a tool that employs reference points (landmarks) and allows for the independent analysis of shape and size. We aim to determine whether environmental characteristics predict shape variation in Cycloramphidae and expect to find different traits explaining variation in terrestrial and saxicolous groups. This is the first time ecogeographical rules have been tested against shape variation isolated from size. The results may clarify peculiarities of amphibians compared to other tetrapods and foster discussions on the group's evolution and conservation in the face of current environmental pressures, such as those related to climate change.