Skeletal Anomalies in Juveniles of Siberian Grayling Thymallus arcticus (Pallas, 1776) from the Mana River (Middle Yenisei River System) under Artificial and Natural Reproduction

Abstract

The paper contains data on diversity and frequency of occurrence of skeletal anomalies in larvae and juveniles of Siberian grayling from the Mana river (Middle Yenisei River system) grown both in the temporary fish-breeding farm and under natural conditions. The qualitative and quantitative characteristics of morphological abnormalities in the Siberian grayling in aquaculture were described for the first time. A total of 58 skeletal deformities belonged to 27 types and located in 7 regions of the skeleton were detected. The average frequency of occurrence of abnormal fish was 7.8 %. Significant differences between juveniles from natural and artificial reproduction were found only at the late stages of their development (at a length of 21-39 mm). Proportion of individuals with skeletal deformities among grayling’s juveniles developing in fish-breeding farm was 11.1 %, which doesn’t exceed the occurrence of morphological abnormalities in fish inhabiting natural water bodies of the Yenisei River system (13.0-31.0 %)

Keywords

• Siberian grayling
• skeletal anomalies
• Yenisei
• Mana
• temporary fish-breeding farm