Goldfish: domestication has selected malformations

Goldfish, for a millennium, have been selected for ornamental traits, creating hundreds of varieties with unusual characteristics – fins, skull shapes, varied colors. All from one species, Carassius gildedthese surprising morphologies are the result of intense human selection, aimed at producing aesthetic and non-functional traits. Unlike selection for productive traits, as in pigs or cows, this approach involves pure ornamentation, similar to that observed in dogs or cats. But at what price for these fish?

Domestication to the point of malformation: the excesses of ornamentation

After X-ray analysis of fifteen varieties of goldfish and distantly related wild species, a new study reveals that the process of domestication has selected for notable malformations in their bodies, skulls and spines. These transformations, far from natural forms, are only viable in captivity, which raises ethical questions about the selection of aesthetic traits to the detriment of the health and well-being of the animal. What is the effect of domestication? What deformations are selected? Answers with Kévin Le Verger, post-doctoral researcher at the University of Zurich and first author of this study published in Evolution Letters.