Sunday, February 18, 2018

[Ichthyology • 2018] Enneapterygius velatus • A New Deepwater Triplefin (Perciformes: Tripterygiidae) from the Ryukyu Islands, southern Japan

Enneapterygius velatus
Tashiro, Senou & Motomura, 2018

A new deepwater speciesEnneapterygius velatus sp. nov. (Perciformes: Tripterygiidae), is described from two male specimens from Ryukyu Island, southern Japan, the holotype having been collected at a depth of 55 m and an underwater photograph taken between 30 and 41 m depth. The new species is characterized by an extremely long first dorsal-fin spine (length 31.6–34.0 % of SL), the first dorsal-fin spine bases close together, first dorsal-fin base length less than half the distance between the base of the third spine of the first dorsal-fin and origin of second dorsal-fin, first dorsal-fin spine base with developed inclinator muscles, long pelvic fins (tip of second ray extending beyond anal-fin origin), large body scales (8 circumpeduncular scales), the supratemporal sensory canals deeply U-shaped in dorsal view, snout profile weakly rounded, abdomen from between pelvic-fin bases to anal-fin origin covered by cycloid scales, body lacking significant blackish blotches and caudal-fin base with scattered melanophores in preserved specimens.

Keywords: Description, Enneapterygius mirabilis, Enneapterygius tutuilae, Deep-reef, Morphology 

Fig. 4 Underwater photograph of Enneapterygius velatus sp. nov. from Okinawa-jima Island, Japan, 30–41 m depth, 14 May 2012. Photo by T. Katano 

Enneapterygius velatus sp. nov.
(New English name: Sail Triplefin; new Japanese name: Hotate-hebigimpo) 

Distribution. Currently known only from the Ryukyu Islands, southern Japan [Amami-oshima Island (Amami Islands), and Okinawa-jima and Kume-jima islands (Okinawa Islands)], the Okinawa-jima record being based on an underwater photograph taken at a depth between 30–41 m (Fig. 4). The species inhabits relatively deep reefs. The holotype was collected from a rubble bottom in the outer edge of coral reefs at a depth of 55 m.

Etymology. The specific name “velatus” is derived from Latin meaning “sail”, in reference to the high first dorsal-fin of the species.

Satokuni Tashiro, Hiroshi Senou and Hiroyuki Motomura. 2018. Enneapterygius velatus, A New Deepwater Triplefin (Perciformes: Tripterygiidae) from the Ryukyu Islands, southern Japan. Ichthyological Research. DOI: 10.1007/s10228-018-0617-8