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Issue: Vol. 5821 No. 4: 3 Jun. 2026
Type: Article
Published: 2026-06-03
DOI: 10.11646/zootaxa.5821.4.7
Page range: 545-558
Abstract views: 33
PDF downloaded: 0

Two new species of the barbeled dragonfish genus Eustomias (Teleostei: Stomiiformes: Stomiidae) from the North Pacific Ocean, with a key to species of the subgenus Triclonostomias

Faculty of Fisheries Sciences; Hokkaido University; 3-1-1 Minato-cho; Hakodate; Hokkaido 041-8611; Japan; Fisheries Science Center; The Hokkaido University Museum; 3-1-1 Minato-cho; Hakodate; Hokkaido 041-8611; Japan
Pisces Eustomias oshoromaru Eustomias clarkei Eustomias drechseli Eustomias furcifer mesopelagic fishes deep-sea taxonomy

Abstract

Two new barbeled dragonfishes, Eustomias oshoromaru sp. nov. and E. clarkei sp. nov., are described on the basis of a single specimen collected from the Ogasawara Islands and two specimens from the Hawaiian Islands, respectively. The two new species are included in the subgenus Triclonostomias Regan & Trewavas, 1930, characterized primarily by 8 pelvic-fin rays, and 3 branches arising together from the externally pigmented barbel stem. Both species are similar to E. furcifer Regan & Trewavas, 1930 and E. drechseli Regan & Trewavas, 1930 in having the barbel swollen and externally unpigmented distal to the origins of the barbel branches. However, E. oshoromaru sp. nov. is distinguishable from these species by the following combination of characters: 5 pectoral-fin rays; 3 barbel branches arising together from a part slightly before the barbel mid-point [barbel stem base to origin of branches 45.1% of barbel length (BL)]; terminal swelling with single lengthwise dark line extending to near base of terminal bulb. Eustomias clarkei sp. nov. is diagnosed by the following combination of characters: 7 pectoral-fin rays; 3 barbel branches arising together from a part clearly beyond the barbel mid-point (barbel stem base to origins of branches ca. 67.8–76.3% of BL); proximal part of medial barbel branch with single elaborately ramified branch; single lengthwise dark line on terminal swelling barely reaching mid-point. A revised diagnosis of the subgenus Triclonostomias and key to species are also provided.

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How to Cite

Kimura, K. (2026) Two new species of the barbeled dragonfish genus Eustomias (Teleostei: Stomiiformes: Stomiidae) from the North Pacific Ocean, with a key to species of the subgenus Triclonostomias. Zootaxa, 5821 (4), 545–558. https://doi.org/10.11646/zootaxa.5821.4.7