Pond Smelt Hypomesus olidus, a New Species of the Ichthyofauna of the Commander Islands

Abstract—The population of pond smelt Hypomesus olidus has been registered for the first time in the water bodies of Bering Island (Commander Islands). The spawning of this species has been observed in the Sarannoe Lake system, and the maturing breeders have been caught in the freshwater-brackish Gavanskoe Lake system. The spawning grounds, the spawning period, the environment, and the morphology of the breeders have been described. The ratio of Ca and Sr isotopes in the otoliths of the pond smelt inhabiting the Sarannoe Lake system evidenced that this species here was presented by the resident ecotype. The problem of the smelt phylogeny and resettlement in the northern Pacific Ocean is discussed.