Effect of tactile stimulation on the appeasement behavior of a neotropical cichlid fish

• Grant number: 23/04059-1
• Support Opportunities: Scholarships in Brazil - Master
• Start date: September 01, 2023
• End date: December 31, 2024
• Field of knowledge: Biological Sciences - Zoology - Animal Behavior
• Principal Investigator: Eliane Gonçalves de Freitas
• Grantee: Bianca Cambiaghi e Silva
• 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 scholarship(s): 23/15708-0 - Tactile stimulation and the association with brain monoamines in fish, BE.EP.MS

Abstract

Tactile body stimulation, similar to human therapeutic massage, reduces aggression and in territorial fish. This effect may occur by reducing the attacks from dominant fish or by the faster appearance of appeasement behaviors by the subordinate ones. The aim of this study is to test the effect of body tactile stimulation on appeasement behavior in the cichlid fish Geophagus iporangensis. For this, we developed an apparatus formed by a PVC frame, filled with plastic sticks containing silicone bristles on their sides. The apparatus is placed in the center of the glass tank and the fish receive tactile body stimulation when passing through the bristles. The animals will remain for 21 days in a treatment with stimulation or in a control one, without the silicone bristles. Then, each individual will be paired with another one to observe fights and to quantify appeasement behavior. After the fights, blood will be collected for evaluation of plasma cortisol (an indicator of stress). The animals will then be euthanized for removal of the brain and subsequent measurement of monoamines (dopamine and serotonin), as a possible mechanism associated with the reduction of aggressiveness. This project is innovative, as it involves areas of knowledge that are little explored, particularly in fish. In addition, the work could generate low-cost technology to mitigate the impacts of fish rearing and management systems, adding value to the aquaculture trade.