In a groundbreaking study poised to reshape aquaculture breeding strategies, researchers have uncovered crucial insights into how social behavior influences genetic selection in farmed fish. By integrating complex social interactions into breeding program simulations, the team demonstrated that the indirect genetic effects driven by social dynamics significantly alter both phenotypic variability and genetic gain.
Aquaculture systems typically rear fish in densely populated groups, where social interactions among individuals are constant and impactful. Traditional breeding programs often overlook these indirect genetic effects (IGEs), focusing primarily on direct genetic contributions to economically important traits. This omission can lead to incomplete understanding of selection responses. The new study fills this gap by modeling breeding outcomes that incorporate heterogeneous social effects influencing fish growth and other key traits.
The researchers simulated a virtual breeding population totaling 2000 selection candidates, originating from 1000 families constructed via a partial mating design involving 100 males and 100 females. This framework allowed them to account for both direct genetic effects and social interactions shaped not only by the target phenotype but also by two underlying personality traits latent within the fish. Such an approach captures the nuanced ways individual behavior affects group performance.
Findings revealed that as the magnitude of social interaction effects increases, the phenotypic variance within the target trait also escalates. This heightened variability can complicate the selection process but may harbor untapped potential for improving desirable traits. Under conventional mass selection protocols, the genetic means of personality-linked traits shift depending heavily on the genetic correlations between these traits and the focal phenotype, illustrating how behavioral genetics intertwine with production traits.
The study also contrasted mass selection with group-based selection strategies. Group selection aiming for equivalent genetic gains necessitates a higher number of groups composed of fewer families, indicating logistical challenges for practical breeding implementation. Interestingly, while phenotypic variance and personality trait means remain relatively stable under group selection, there is a trade-off as inbreeding rates per generation increase. However, this rise in inbreeding occurs consistently across different group configurations, suggesting predictable management measures can mitigate potential risks.
By emphasizing the role of personality traits, the research underscores the importance of considering behavioral genetics when optimizing selection schemes. Such traits can have subtle but profound indirect effects on productivity, social stability, and welfare in densely farmed aquatic species. Ignoring these components risks selecting for individuals that perform well in isolation but falter under real-world social conditions.
This pioneering work presents vital considerations for the design of future breeding programs that could boost efficiency and sustainability in aquaculture. Incorporating social effect metrics will enable breeders to harness the full genetic potential of farmed fish populations while maintaining genetic diversity and animal welfare.
As global demand for seafood rises, innovations like these offer promising pathways toward more resilient and productive aquaculture systems. This study propels the field forward by bridging behavioral ecology, quantitative genetics, and practical breeding, signaling a new era of socially informed selection strategies.
Subject of Research: Fish breeding programs accounting for social behavior and indirect genetic effects in aquaculture.
Article Title: Modeling breeding programs considering social behavior in large groups of farmed fish.
Article References:
Rovere, G., Cuyabano, B.C.D. & Phocas, F. Modeling breeding programs considering social behavior in large groups of farmed fish. Heredity (2026). https://doi.org/10.1038/s41437-026-00864-3
DOI: 13 July 2026
