Body shape variation between farms of tilapia (Oreochromis sp.) in Colombian Andes using landmark based geometric morphometrics

Tilapia is the most economically important fish in the aquaculture of different countries from the Americas. This species exhibits morphological plasticity under different conditions. In this study, we used landmark-based geometric morphometric to describe the shape variation of two red and one Nile tilapia farmed populations in Colombian Andes. We recorded significant morphological differences between all studied farms (P < 0.001, in the multivariate analysis of variance). In this way, individuals from the Nile tilapia farms were more elongated and had a more ventral position of the posterior extreme of the orbit and the insertion of pectoral fin than red tilapias. Moreover, the Nile group showed a shorter space between the mouth profile and the posterior extreme of the orbit, compared to red groups. On the other hand, individuals from farm red 2 were deep bodied and had a smaller head compared to tilapias from farm red 1. Our results provide evidence that tilapias from different farms in Colombian Andes display differences in body shape, and can be applied to selective breeding programs after establishing the contribution of genetic and environmental effects on tilapia shape as well as the preferences of consumers for the body shape of the species.