Effects of populational connectivity on individual fitness: a case-study in pinnotherid crabs associated to sand dollars

• Grant number: 18/25562-5
• Support Opportunities: Scholarships in Brazil - Master
• Start date: March 01, 2019
• End date: August 31, 2020
• Field of knowledge: Biological Sciences - Ecology - Applied Ecology
• Principal Investigator: Augusto Alberto Valero Flores
• Grantee: Juliana de Andrade Souza
• Host Institution: Centro de Biologia Marinha (CEBIMAR). Universidade de São Paulo (USP). São Sebastião , SP, Brazil

Abstract

Habitat loss and fragmentation of natural landscapes is considered one of the most serious environmental threats, and little is known on how the physical and biological properties of the connectivity matrix, generally secondary and impoverished habitat, affect the stability of biological populations and the performance of individuals. This project approaches this issue in a particularly tractable system: pea crabs distributed on sand dollars, the latter working as discrete habitat patches, separated by distances than can be easily covered using SCUBA. In a first stage, maps will be constructed to describe the spatial distribution of sand-dollars and their crab populations, and the environmental parameters predation potential,temperature, grain size and organic matter of sediments will be assessed at different sampling sites within the São Sebastião Channel. In a second phase, the larval release rate of each combination of adult crabs found on sand-dollars will be estimated in the laboratory to assess individual fitness. The analyses of these data will allow to (i) identify the environmental variables that most likely contribute to crab connectivity, (ii) assess how connectivity may influence crab clustering in sand-dollars (number of individuals and sex ratio), and (iii)understand how connectivity may ultimately affect crab per capita reproductive value. It is also planned to conduct a secondary laboratory experiment in which the environmental variables identified above are manipulated to (iv) verify whether correlational evidence truly reflect cause-effect relationships. (AU)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

SOUZA, Juliana de Andrade. Abundance and active patch selection modulate reproductive connectivity and fitness of pea crabs living on sand dollars. 2021. Master's Dissertation - Universidade de São Paulo (USP). Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (PCARP/BC) Ribeirão Preto.