Effect of natural vs. artificial body tactile stimulation on the client fish, Chaetodon auriga

• Grant number: 25/11260-0
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• Start date: December 01, 2025
• End date: November 30, 2026
• Field of knowledge: Agronomical Sciences - Fishery Resources and Fishery Engineering - Aquaculture
• Principal Investigator: Eliane Gonçalves de Freitas
• Grantee: Ana Carolina dos Santos Gauy
• Supervisor: Marta Sofia Candeias Soares
• 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
• Institution abroad: Aquário Vasco Da Gama, Portugal
• Associated to the scholarship: 23/02991-6 - Effect of the free choice for tactile stimulation on aggressive interaction, brain monoamine levels, and productive performance in Nile tilapia fish, Oreochromis niloticus (L.), BP.PD

Abstract

Body tactile stimulation (TS), natural or artificial, is a mechanical stimulus that promotes positive effects such as stress reduction and an increase in monoamines in various animals, including fish. In coral reefs, TS is crucial in mutualistic cleaning interactions between client and cleaners fish, where TS offered by cleaners has been shown to reduce cortisol in clients after stress. Thus, the aim of this project is to compare the behavioral and physiological responses of the yellowfin butterflyfish (Chaetodon auriga), a client fish species, when subjected to natural and artificial TS. Three treatments will be carried out with pairs of C. auriga (N = 12 each treatment): 1) With artificial TS (using an apparatus with silicone bristles); 2) With natural TS (interaction with the cleaner fish, Labroides dimidiatus); 3) Control (apparatus without bristles, without artificial or natural TS). The client fish will remain in the presence of the apparatus/cleaner for 20 days and will be filmed daily (1h/day) to analyze the frequency and duration of the client fish's interaction with the apparatus/cleaner. On day 21, half of the client fish from each treatment will be subjected to confinement stress (30 min) and will then be euthanized, while the other half will be euthanized immediately. The heads and gills will be stored at -80°C for later analysis of brain monoamines (serotonin, dopamine and their metabolites) and cortisol, respectively. It is hoped that artificial TS will provide benefits to the client fish, as well as natural TS, and can be used as environmental enrichment to improve the welfare of ornamental fish. (AU)