Ecophysiological characterization in fiddler crabs from the Indian Ocean: a comparative and experimental approach

• Grant number: 25/10490-2
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate (Direct)
• Start date: August 25, 2025
• End date: November 24, 2025
• Field of knowledge: Biological Sciences - Physiology - Compared Physiology
• Principal Investigator: Samuel Coelho de Faria
• Grantee: Luiza Grassi Villela
• Supervisor: Nasreen Peer
• Host Institution: Centro de Biologia Marinha (CEBIMAR). Universidade de São Paulo (USP). São Sebastião , SP, Brazil
• Institution abroad: Stellenbosch University, South Africa
• Associated to the scholarship: 22/14344-2 - A phylophysiological evaluation of osmotic and ionic regulatory mechanisms in Fiddler Crabs (Brachyura, Ocypodidae: Gelasiminae e Ocypodinae) from the Neotropical Coasts of Equador and Mexico, BP.DD

Abstract

Fiddler crabs are typically found in the intertidal region, particularly in estuaries, mangroves, and salt marshes. They demonstrate a remarkable capacity to cope with physiological challenges imposed by the environment, being highly responsive. Thus, they constitute an insightful model group for ecophysiological and evolutionary investigations. We already investigated the ecophysiology of fiddler crabs of three genera, including 19 species across three biogeographical areas: (i) the Pacific coast of Ecuador and the Galapagos Islands; (ii) the Pacific coast of Mexico, in the southern region, along the state of Oaxaca (Pacific Ocean); and (iii) the Gulf of Mexico and the Caribbean Sea, in the Yucatán Peninsula (Atlantic Ocean). We focused on Neotropical America region, particularly the Pacific coast - unknown until this current project. Now, we are motivated to focus our research on the east coast of South Africa (Indian Ocean). Trought a comparative approach, we aim to reconstruct the evolutionary history of osmo- and iono-regulation, testing whether salinity is a driver of osmo- and iono-regulatory evolution, whether these parameters may have coevolved and whether the clades from the Indo-Pacific have a more limited osmoregulatory ability than those from the Atlantic coast of the Americas, for example. We are also proposing an experimental approach related to fiddler crabs' physiology and ecology in the context of climate change led by Dr Nasreen Peer (University of Stellenbosch). For this second objective, we aim to test the combined effects of acclimation salinity, temperature increase, and desiccation on the physiology of one fiddler crab species. This BEPE proposal aims to advance the current comparative investigation of fiddler crab species from the major oceanic biogeographical regions and provide a valuable opportunity to incorporate and learn new scientific methods and experimental approaches. The investigation of the evolutionary and ecological bases of physiological mechanisms may constitute an important tool to understand future scenarios of species. (AU)