Brain complexity and cognition related to fish social behavior

• Grant number: 16/26160-2
• Support Opportunities: Regular Research Grants
• Start date: September 01, 2017
• End date: February 29, 2020
• Field of knowledge: Biological Sciences - Zoology - Animal Behavior
• Principal Investigator: Eliane Gonçalves de Freitas
• Grantee: Eliane Gonçalves de Freitas
• Host Institution: Instituto de Biociências, Letras e Ciências Exatas (IBILCE). Universidade Estadual Paulista (UNESP). Campus de São José do Rio Preto. São José do Rio Preto , SP, Brazil
• Associated researchers: Rui Oliveira
• Associated scholarship(s): 19/10808-1 - Brain complexity and cognition related to fish social behavior, BP.TT

Abstract

The cerebral organization in social animals can be explained by both, phylogenetic relationships (i.e., the brain evolves by a line of interrelationship between species) and by the selection of structures driven by the complexity of the social environment. The aim of this study is to compare the possible association between social behavior, brain complexity and cognitive ability in close related fish species within the Cichlidae family; which present social interactions considered more complex (biparental brood care in monogamous species) or less complex (maternal brood care in polygynous species). Four species will be tested for social memory, sociability, aggressiveness and cognitive flexibility. They will have their brains dissected in macro-areas (telencephalon, optic tectum, cerebellum, dorsal medulla, olfactory bulb, pituitary and hypothalamus), whose volumes and number of neurons will be quantified. The data will be analyzed by GLM tests, correlations and hierarchical clustering to compare the associations between the predictors (brain, cognition and social complexity). Brain structures will also be dissected and analyzed in other species, but without behavioral tests. Androgen and cortisol measurements will be performed as they are associated with the organizational and activational mechanisms of the social brain network. Species with similar social strategies are predicted to show more similarities than more closely related species. This study is innovative, since little is known about the evolutionary and physiological mechanisms involved in the control of social behavior of Neotropical fish. (AU)