Editorial Type:
Article Category: Research Article
 | 
Online Publication Date: 23 Feb 2023

Description of a New Deep-Water Eulophiid Fish (Perciformes: Zoarcoidei) from Japan

,
,
, and
Page Range: 87 – 97
DOI: 10.1643/i2021047
Save
Download PDF

The genus Eulophias, which is an enigmatic group of the suborder Zoarcoidei, previously comprised two rare species: Eulophias tanneriSmith, 1902 (type species and a senior synonym of Eulophias owashiiOkada and Suzuki, 1954) and Eulophias koreanusKwun and Kim, 2012. Here we describe a new species, Eulophias spinosior, based on 71 specimens (94.9–182.3 mm in standard length, SL) collected from the upper slope of the northwestern Pacific off southern Japan at depths of 257–555 m. It readily differs from its two congeners in having 133–143 dorsal-fin spines, 109–116 anal-fin soft rays, 5–6 pectoral-fin rays, and 146–156 total vertebrae, and in lacking a dark band posterior to the eye and a series of dark blotches midlaterally on the trunk and tail. Regarding bathymetric distribution, the new species occurs much deeper than E. koreanus and E. tanneri. Eulophias spinosior, new species, is sexually dimorphic, with males having large, stout, modified canines at the tips of the premaxillary and dentary (vs. only slightly enlarged in females). Dentition of males also differs from that of females in that most teeth are uniserially arranged in each jaw (vs. distinct two rows anteriorly).

Copyright: © 2023 by the American Society of Ichthyologists and Herpetologists
Fig. 1.
Fig. 1.

Holotype of Eulophias spinosior. BSKU 107826, male, 182.3 mm SL, Tosa Bay, 257–290 m depth. (A) Lateral view; (B) close-up lateral, (C) dorsal, and (D) ventral views of the head and trunk. Preserved.

Fig. 2.
Fig. 2.

Fresh specimens of Eulophias spinosior. (A–E) BSKU 118798, paratype, sex undetermined, 155.0 mm SL, Tosa Bay, 300 m depth, soon after capture; (F) BSKU 118835, paratype, sex undetermined, 135.3 mm SL, Tosa Bay, 300 m depth, freshly thawed. (A, F) Lateral views; (B) close-up lateral, (C) dorsal, and (D) ventral views of the head and trunk; (E) close-up lateral view of the posterior part of the tail.

Fig. 3.
Fig. 3.

Illustrations showing sexual dimorphism in dentition of Eulophias spinosior. (A–D) Male, BSKU 83207, paratype, 167.2 mm SL; (E–H) female, BSKU 83206, paratype, 180.2 mm SL. (A, E) Mesial and (B, F) ventral views of the right premaxillary; (C, G) mesial and (D, H) dorsal views of the right dentary.

Fig. 4.
Fig. 4.

Illustrations showing the cephalic sensory pores of Eulophias spinosior. BSKU 118798, paratype, 155.0 mm SL. (A) Dorsal, (B) lateral, and (C) ventral views of the head. Abbreviations: inf, infraorbital pores; int, interorbital pore; man, mandibular pores; n, nostril; nas, nasal pores; occ, occipital pores; pos, postorbital pores; pre, preopercular pores.

Fig. 5.
Fig. 5.

Maps of (A) the northwestern Pacific and (B) southern Japan showing distribution of three species of Eulophias. Stars, circles, and square represent localities of E. spinosior, E. tanneri, and E. koreanus, respectively. “H” indicates the type locality of each species.

Contributor Notes

1 Department of Marine Biology, School of Marine Science and Technology, Tokai University, 3-20-1 Orido, Shimizu, Shizuoka 424-8610, Japan; Email: gadiformes@gmail.com. Send correspondence to this address.
2 Laboratory of Marine Biology, Department of Biological Sciences, Faculty of Science and Technology, Kochi University, 2-5-1 Akebono-cho, Kochi 780-8520, Japan.
3 Department of Fisheries, School of Marine Science and Technology, Tokai University, 3-20-1 Orido, Shimizu, Shizuoka 424-8610, Japan.

Associate Editor: M. T. Craig.

Received: 13 Apr 2021
Accepted: 08 Dec 2022
  • Download PDF