Scientists from the A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences, the P.P. Shirshov Institute of Oceanology of the Russian Academy of Sciences, the N.I. Vavilov Institute of General Genetics of the Russian Academy of Sciences and the All-Russian Research Institute of Fisheries and Oceanography have obtained for the first time data on a rare fish species - the Alaskan sculpin Triglops metopias (Cottidae) from the Russian waters of the Kuril Islands.
The Alaskan sculpin is a rare and poorly studied species with a limited range in the northern Pacific Ocean. Previously, this species was thought to be distributed in the waters of the Aleutian Islands and the western Gulf of Alaska; information on its presence in Russian waters was extremely contradictory, and reliable finds were absent. The results of the study confirmed the occurrence of T. metopias in the northwestern Pacific Ocean along the Kuril Islands. Forty-one specimens were subjected to morphological and genetic studies, including principal component analysis (PCA) and DNA barcoding. The latter, based on the sequences of the mitochondrial Cyt b gene, did not reveal any differences between the studied species and the closely related T. pingelii, although they can be distinguished by external morphology, including the use of PCA. Despite the morphological similarity of T. metopias and T. pingelii, both species are clearly distinguished by a combination of countable and visual characteristics.
Fig. 2. Locations of catches of the Alaskan sculpin Triglops metopias in the northern part of the Pacific Ocean: A – in the waters of Alaska, B – in the waters of the Kuril Islands (1 – published data, 2 – unpublished data).
The species under consideration has a fragmented range in the northern Pacific Ocean, inhabiting only the waters of the Kuril and Aleutian Islands, as well as the western part of the Gulf of Alaska. Similar ranges were previously described for a number of fish species, such as the scaled sculpin Archistes biseriatus, the longfin Irish lord Hemilepidotus zapus, the spineless sculpin Phallocottus obtusus, the papillose lumpsucker Eumicrotremus barbatus, the cherry snailfish Allocareproctus jordani, the black-clawed snailfish Careproctus zachirus, the bigeye snailfish Temnocora candida and some others, which were singled out into a special group of "island" species. They probably colonized the waters of their habitats by transferring pelagic eggs, larvae, and early juveniles by the waters of the Western Subarctic Gyre.
Published data of the article: Prokofiev, A.M., Mukhametov, I.N., Emelianova, O.R., Orlova, S.Y., Orlov, A.M. 2025. Identity and distribution of Triglops metopias (Teleostei, Cottidae) in the Northwestern Pacific // Journal of Marine Science and Engineering. V. 13. Art. 182.