Integrating geometric morphometrics to biotechnology: a multivariate approach to discriminating, males, females, gynogenetic, and diploid and triploid juveniles in an important Neotropical characid

As the world’s population continues to grow, the demand for food fish and animal protein is increasing proportionally, leading to the depletion of fish stocks in both marine and freshwater environments. In this pressing scenario, aquaculture emerges as one solution, offering sustainable production methods and employing biotechnological approaches to conserve genetic resources while satisfying the increasing demand for animal protein. In this study, we employ an innovative approach, namely, geometric morphometrics, to discern and delineate the distinctive features of diploid, gynogenetic, and triploid Astyanax altiparanae fish. Our findings reveal morphological differences, particularly in body modifications, across these genetic variants. Applying discriminant analysis, principal components (PC) analysis (PC1 = 32.11%, PC2 = 12.83%, PC3 = 11.56%), and canonical variates (CV) analysis (CV1 = 52.59%, CV2 = 32.53%), we were able to successfully identify and differentiate diploid, triploid, and gynogenetic A. altiparanae individuals. These groups are characterized by their early growth rates during the initial months of development, as well as by sexual dimorphism between groups (F = 20.06, p < 0.0001). Such insights have significant practical implications, not only for advancing biotechnology and animal husbandry techniques but also for optimizing aquaculture practices specific to A. altiparanae. By enhancing our understanding of phenotypic patterns, this study paves the way for maximizing production and unlocking the potential of this Neotropical characid species in aquaculture and biotechnology.