The Morphological Characteristics of the Danube Ruffe, Gymnocephalus baloni (Perciformes, Percidae), in the Upper Reaches of the Dnipro River, Ukraine

Tsyba, A. O., Kokodiy, S. V.



In the upper reaches of the Dnipro it was found a Danube ruffe population. It diff ers from the population of the middle reaches of the Dnipro by a longer caudal peduncle. The Danube ruffe differs from sympatric populations of the common ruffe by 10 features. For a fast and precise identification of these two species, it was proposed to use the height of the membrane between the first and second rays of the anal fin as a percentageto the length of the body.