Comparative study of the growth, survival and morphology of the whitefish hybrids and parent species in the first year of rearing in cage aquaculture

Abstract

The purpose of the work: to estimate fish breeding indicators of three hybrid forms of whitefish in comparison with parental species when grown in cage aquaculture.Methods used: the production and cultivation of hybrids and parental species were carried out using standard technology for whitefish from November 2021 to May 2022. We have studied the survival and growth rate of fingerlings, and we also conducted a comparative assessment of the exterior of yearlings using factor and cluster analyses.Novelty: for the first time, three hybrid forms of peled and parent species (peled, muksun, broad whitefish, nelma) were grown in cages, and a comparative analysis of survival, growth and morphology of hybrids and parent species was performed.Results: all hybrid forms occupy an intermediate position in terms of growth rate, surpassing the maternal species (peled), yielding to the paternal ones. The best results in terms of weight and linear growth among hybrids were noted in pelchir. In terms of survival, oneyearlings of all hybrids show the effect of heterosis, although at the stage of larvae and early juveniles, the superiority in survival of hybrid forms over the parental pair was noted only in pelnelm. The survival rate of hybrid eggs, as well as the survival rate of pelchir and pelmuk at the early stages of cultivation, had intermediate values — lower than that of peled, but significantly higher than that of paternal species. The lowest survival rate of eggs among hybrids is shown in pelchir. The peled has the most significant morphological differences from other pure species and hybrid forms used in the experiment, all hybrid forms show more similarity with the paternal species.Practical significance: results provide a potential assessment of whitefish hybrids for the prospect of their use in commercial aquaculture.