First Report of Xanthic Phenotype of the Common Bream Abramis brama (Linnaeus, 1758) from Krasnoyarsk Reservoir, Russian Federation

Abnormal body colouration in fishes usually occurs as either a deficiency or an excess of various pigmented substances. Despite the fact that abnormal pigmentation is known in many fish species, they are extremely rare and of significant interest from the point of view of aquaculture, evolutionary biology and behavioural ecology. One of the forms of abnormal pigmentation is xanthism, expressed by the appearance of a yellow or orange colour. The article reports about the capture of a female common bream Abramis brama (Linnaeus, 1758) with abnormal xanthic colouration in the Znamensky Bay of the Krasnoyarsk Reservoir, Russian Federation (54°26'07.2"N, 91°11'55.3"E) in June 2020. The xanthic individual had a pinkish-orange colouration of the dorsal and sides of the body, and the pectoral fins. The pelvic, dorsal, caudal, and anal fins are dark orange in colour and almost brown at the tips. The aetiology of abnormal pigmentation as in this case is not always clear. It is assumed that this variation of the common bream pigmentation is caused by a non-pathological genetic mutation, as in the cases of many other fish species described in scientific literature currently.