First findings of genera Neoscolecithrix and Bradyetes (Copepoda: Calanoida) in the Arctic Ocean with remarks on the Arctic deep-water near-bottom calanoids

The list of benthopelagic calanoids of Svalbard and the adjacent Arctic Ocean waters is updated to 11 calanoid species and genera, and maps of their global distribution are given. Two calanoid species, Neoscolecithrix magna (Grice, 1972) and Bradyetes weddellanus Markhaseva et Schulz, 2006, are for the first time recorded for the Arctic Ocean in the samples collected on board RV Polarstern in 2017 near Svalbard, in the region of the Yermak Plateau slope together with Crassarietellus septentrionalis Markhaseva, Soldatenko et Renz, 2022, Cenognatha farrani (Smirnov, 1935) and Tharybis groenlandicus (Tupitsky, 1982). The original descriptions and key taxonomic characters for the species Neoscolecithrix magna and Bradyetes weddellanus are emended by showing their morphological variation and completing information on the previously poorly described or missing descriptive characters. A species list of the Arctic Ocean calanoid copepods that are obligate and predominantly benthopelagic was compiled and is presented. It comprises 21 species in 16 genera, of which one genus and 10 species are found to be biogeographically limited to the Arctic Ocean. Most taxa (14 genera out of 16) of the Arctic benthopelagic calanoids belong to the evolutionary youngest calanoid superfamily Clausocalanoidea, while only two benthopelagic genera belong to the superfamilies Ryocalanoidea (Yrocalanus Renz, Markhaseva et Schulz, 2013) and Arietelloidea (Crassarietellus Ohtsuka, Boxshall et Roe, 1994).