Integrative redescription of Canthocamptus (Baicalocamptus) longifurcatus (Harpacticoida: Canthocamptidae), an endemic species from Lake Baikal

Abstract

A redescription of the Lake Baikal endemic species, Canthocamptus (Baicalocamptus) longifurcatus Borutzky, 1947 (Harpacticoida: Canthocamptidae), is provided. The illustrated redescription of morphology of the female and male is supplemented by a genetic barcoding based on sequences of the mitochondrial COI marker. Canthocamptus (B.) longifurcatus is morphologically very similar to another representative of the subgenus, C. (B.) verestschagini (Borutzky, 1931), but can be well distinguished from the latter by the armature of the female furca and the structure of the last pair of swimming legs in the female and male. An analysis of the obtained COI sequences and their comparison with those of other harpacticoid species confirmed that C. (B.) longifurcatus belongs to the genus Canthocamptus Westwood, 1836: the smallest genetic differences (on average, 29.5%) were observed between the studied Baikal species and C. staphylinus Jurine, 1820 from Europe (Lake Geneva, Switzerland).