Differentiation of Arctic Charr Salvelinus alpinus Complex (Salmonidae) in Lakes Lama and Kapchuk (Taimyr) Based on Genetic Analysis, External Morphology, and Otolith Shape

The analysis of 17 microsatellite loci reveals five general forms of Arctic charr Salvelinus alpinus in large lakes Lama and Kapchuk (Norilo-Pyasinskaya water system, Taimyr) connected by the river. Three of them are represented by sister pairs, and, thus, eight reproductively isolated forms are defined. The immature individuals of different forms are hardly identified by external morphology. For the morphological differentiation of the five general forms, multivariate analyses of morphometric parameters of the body, otolith shape indices, and wavelet coefficients describing otolith contours are applied. All analyses show that goggle-eyed charr (“pucheglazka”) substantially differs from the other forms. The relationships between the four other general forms are variable depending on the method of analysis. Besides, a certain difference is observed in the data evaluating the left and right otolith shapes. The total correct jack-knifed classification of the forms in the linear discriminant analyses is 55.9% for morphometric indices and reaches 56.1 and 61.4% for the left and right otolith shapes assessed by wavelet transform. The overall morphological similarity of the forms can be explained by their parallel evolution in a restricted number of available trophic niches.