Finding of the Thermophilic Harpacticoid Species Elaphoidella bidens (Schmeil 1893) in the Vychegda River (Northern Dvina, White Sea Basin)

Abstract

A harpacticoid copepod (Copepoda: Harpacticoida) species, Elaphoidella bidens, which was new for the North-East of European Russia, was found in the Vychegda River in July 2018. The species was identified in the area where heated wastewater is discharged from the wood-processing plant. The species was found in the extreme north of its range (61°48′ N). The present study compares the morphological, biological and ecological properties of this species with those of another native representative of the genus – E. gracilis. Comparison of morphology of the Vychegda E. bidens and individuals from tropical populations (New Zealand, Borneo, Vietnam) and populations of the temperate zone (Romania, Lake Glubokoe in Moscow region) showed that the structures of their antennae, body somites, swimming and rudimentary legs, and the caudal rami were similar in representatives of all populations. The fact that a thermophilic species was found for the first time in the northern region is indicative of potential changes in fauna diversity caused by thermal pollution or warming