Morphological variability in lake and river populations of Cottus poecilopus Heckel, 1836 (Pisces: Cottidae)

Abstract

Morphological variability in both population types of Cottus poecilopus Heckel was shown on the basic of study on 316 specimens from 11 lakes and 6 mountain rivers. Rheophilous populations have better developed features related to locomotion; in limnophilous populations cephalic and truncal canals of lateral line are partly reduced. The differences between river and lake populations of Cottus poecilopus involve adaptations to their respective habitats.