Morphological Variation in the Burhot ( Lota lota ) and Recognition of the Subspecies: A Review

A review of the morphometric and meristic variations in 893 specimens of the burbot (Lota lota) from 18 freshwater areas representing the range of the species, showed that Lota lota lacustris (= maculosa), with a short, high caudal peduncle and low meristic values may be distinguished from Lota lota lota, with a long, low caudal peduncle and high meristic values. Lota l. lota occurs from the Volga River system through Siberia and Alaska to the Mackenzie River system in Canada. The populations from the Elbe River and the Danube River are on the periphery of this subspecies, to which it clearly belongs. Lota l. lacustris occurs in southernmost Canada, the United States, and western Europe. Both Lota l. leptura (Hubbs and Schultz, 1941) and Lota l. kamensis (Markun, 1936) are synonyms of Lota l. lota (Linnaeus, 1758).Clinal variations in the means for various characters of the species were found as follows. All meristic values and length of the caudal peduncle as a percentage of standard body length, in general, increased eastward from western Europe as far as 120°E and then decreased toward New England. Predorsal and preanal lengths generally increased eastward from western Europe to New England. The following generally decreased from western Europe eastward to 120°E and then increased toward New England: head length, interorbital width, postpectoral length, and depth of caudal peduncle as a percentage of standard length; depth of caudal peduncle as a percentage of its length; and postpectoral length as a percentage of predorsal length.