Thursday, March 5, 2015

[Ichthyology • 2012] Discordipinna filamentosa • A New Deepwater Goby of the Genus Discordipinna Hoese & Fourmanoir, 1978 (Teleostei: Gobiidae) from Kumejima of the Ryukyus, Japan

Discordipinna filamentosa Chen, Suzuki & Shao, 2012
(New Japanese name: Naginata-haze) 

A new goby species of Discordipinna was collected by trawling from the deep waters off Kumejima, the Ryukyu Islands, Japan. The new species, Discordipinna filamentosa, can be well distinguished from the only other described species, D. griessingeri Hoese & Fourmanoir, 1978, by the following unique combination of features: (1) fins: first dorsal fin rays VI; pectoral fin rays 16; and first dorsal fin with the longest, filamentous first ray in male extending far beyond caudal fin base when adpressed; (2) squamation: longitudinal scale rows 26; transverse scale rows 8 and predorsal naked; (3) dorsal pterygiophore formulae 3/122101/9; (4) head lateral-line system: a longitudinal pattern of infraorbital papillae and both anterior oculoscapular canal and preopercular canal present, lacking posterior oculoscapular canal; and (5) its distinctive coloration. An artificial key to species of Discordipinna is also provided. 

Key words: Discordipinna, Gobiidae, new species, Kumejima, Japan

Discordipinna filamentosa Chen, Suzuki & Shao, 2012
(New Japanese name: Naginata-haze) 

Distribution. So far, the single specimen was collected from the deepwater trawling of up to 82 m depth off Kumejima, Ryukyu, Japan. However, some underwater photographic records taken by Japanese scuba divers have provided live images of this species around Kashiwajima, Shikoku, Japan; Okinawajima, the Ryukyu Islands, Japan; and Malaysia. Based on scuba diving witness and current trawl specimen record, it seems to live in 30 to 82 m depth water with substratum of coral-reef hard debris. 

Etymology. The specific name referred to Latin-“filamentum” meaning the thread-like elongation of fin, a diagnostic feature, as very thin and long extension of the anterior two spinous rays of first dorsal fin.

 Chen, I.-S., Suzuki, T. & Shao, K.-T. 2012. A New Deepwater Goby of the Genus Discordipinna Hoese & Fourmanoir, 1978 (Teleostei: Gobiidae) from Kumejima of the Ryukyus, Japan. (In: Naruse, T., Chan, T.-Y., Tan, H.H., Ahyong, S.T. & Reimer, J.D. (2012) Results of the Marine Biodiversity Expedition — KUMEJIMA 2009) Zootaxa. 3367: 274–280.

Scientific Results of Kumejima Marine Biodiversity Expedition – KUMEJIMA 2009 is now on Zootaxa