Refine
Document Type
- Article (1)
- Part of Periodical (1)
Language
- English (2) (remove)
Has Fulltext
- yes (2)
Is part of the Bibliography
- no (2)
Keywords
- northwestern Pacific (2) (remove)
Three new deep-sea species of Thyasiridae (Mollusca: Bivalvia) from the northwestern Pacific Ocean
(2023)
The Thyasiridae is one of the species-richest families in the abyssal and hadal zones of the northwestern Pacific Ocean. Many thyasirid species dominate benthic communities in terms of abundance and play an important role in the functioning of deep-sea ecosystems. Most of the thyasirid species in the region are new to science and have not been described. Based on the material collected from 1954 to 2016 by seven deep-sea expeditions, three new species of Thyasiridae (Parathyasira coani sp. nov., P. pauli sp. nov., and Thyasira kharkovensis sp. nov.) are described from the abyssal and hadal zones (3210–7540 m depth) of the Sea of Okhotsk, the Bering Sea, as well as the Kuril-Kamchatka and Japan trenches. The new species are remarkable among their congeners due to the combination of the following characters: an obliquely-rhomboidal shell with a weak and shallow posterior sulcus and a large prodissoconch with sculpture of lamellated folds. Comparisons with related species are provided.
A new symbiotic species of liljeborgiid amphipods, Liljeborgia associata sp. nov., is described from the burrows of the spoon worm Urechis unicinctus (Drasche, 1880) (Annelida: Polychaeta: Echiura: Urechidae) in the southern part of Peter the Great Bay and Posjeta Bay in the Sea of Japan. The new species is mostly similar and probably related to Liljeborgia geminata Barnard, 1969, known from the Californian coasts of the USA, and Liljeborgia serratoides Tzvetkova, 1967, described from Posjeta Bay in the Sea of Japan, but can be clearly distinguished from all congeners by morphological features of mouthparts, appendages and telson. The new species is only the fourth in the family Liljeborgiidae to be described from the Russian coast of the northwestern Pacific and the first in association with spoon worms (Echiura).