Social behaviors as welfare indicators in teleost fish

Abstract

Animal welfare is a key issue not only for aquaculture industry and food production, but also for daily husbandry practices in research topics related to physiology in wild and farmed animals. In this context, teleost fish constitute interesting models to assess alternative welfare indicators because of their wide diversity in reproductive and social structures. Any framework for assessing teleost fish welfare needs to account for the physiological mechanisms involved in each species as a first step. A comprehensive approach should also take into account how these physiological and behavioral parameters can be altered by environmental enrichment considering the specific requirements in each case and identifying intrinsic biological characteristics of individual species. This review will show how cortisol and sex steroids regulate social behavior in teleost fish, and how different aspects of social behavior can be employed as welfare indicators according to specific characteristics in each case. This article will consider evidence in teleost fish, including cichlids, characids and cyprinids with different reproductive strategies and social structures (e.g., territorial social hierarchies or shoaling behavior). Neotropical species will be particularly emphasized. The main laboratory-based animal welfare indicators are cortisol, a classical stress hormone, together with sex steroids. Considering that the endocrine landscape is intrinsically related to social behavior, reproductive and agonistic behavioral traits such as aggression, anxiety and courtship are key elements to assess welfare under housing and culture conditions. This review highlights the importance of assessing physiological mechanisms and identifying behavioral characteristics in teleost fish, especially in Neotropical species, as a baseline to understand which environmental enrichment can improve animal welfare in each individual species.

Genetic Advancement, Global Trade Dynamics, Persistent Challenges and Future Prospects in Ornamental Fish Culture

“…), selective breeding has been employed to enhance the social behavior and compatibility of individuals within a group [28]. Studies have shown that certain genetic factors contribute to the development of harmonious social structures that reduce aggression and stress in captive environments [29]. Advancements in molecular genetics have provided a more precise understanding of the genetic basis of ornamental traits.…”

Fish Welfare in Public Aquariums and Zoological Collections

“…The behavioral-based indicators are those traits that are used to visually observe and identify abnormal or maladaptive/sterotypic behaviors of a fish. These behaviors include submissive or aggressive activities, changes in food intake or foraging activities, and changes in schooling or shoaling activities [ 76 , 77 ]. Unfortunately, the majority of species of fish that are maintained in aquarium and zoological settings have never had a thorough documentation of their natural behaviors, and as a result the recognition of subtle abnormal or maladaptive behaviors becomes challenging and generally extrapolated from other species [ 78 ].…”

Arginine-Vasotocin Neuronal System in Steindachneridion parahybae (Siluriformes: Pimelodidae) and Its Influence on Artificially Induced Spawning in Captivity

“…Several groups of neurohormones are involved in mediating social and reproductive behavior via interactions with other neuropeptides or neurotransmitter systems in the fish brain, including alternative phenotypes (variation in social dominance or the control of a territory) and/or social cognition (interactions) [19][20][21][22][23]. Among these neuropeptides, the vasopressin-vasotocin peptide family modulates several processes in reproductive physiology, comprising both aggressive and reproductive behaviors [19,24,25].…”