Morphological variability of the white carp (Hypophthalmichthys molitrix) during domestication

Abstract

Acclimatized in the last century in the reservoirs of Russia, the white silver carp is the only consumer of phytoplankton in our country. In conditions of artificial reproduction and domestication, uncontrolled deterioration of fish habitus often occurs. In this regard, a comparative analysis of the variability of the most informative morphological parameters, namely length, mass, head length, body girth and their main indices in the samples of the white silver carp of varying degrees of domestication, was carried out. The Chinese, Amur and local lineages, the Ergenin sample and the Romanian population were studied, of which the least domesticated is the Chinese line. The presented materials show that the Chinese white carp line of the second generation of domestication differs in a smaller head, high indices of relative head length and physical development from the local and Ergeninsky fish samples domesticated for several decades. In pond lines domesticated in several generations, there is an increase in the relative size of the head and a deterioration in the index of physical development, which indicates the presence of selection for fitness to insufficient food supply in conditions of weak flow. It is recommended in the breeding program when growing reproductive herds of white carp in ponds to provide for selection to preserve the commercial qualities of fish.