Redescription of Nezumia infranudis (Gilbert & Hubbs, 1920), with the first record of the species from the Eastern Indian Ocean (Actinopterygii: Gadiformes: Macrouridae)

Abstract

Nezumia infranudis is redescribed from the holotype and an additional specimen collected from the Timor Sea at a depth of 610–690 m. It belongs to the Nezumia spinosa group (herein defined) and is most similar to the Indo-West Pacific N. spinosa. Nezumia infranudis is distinguished from other congeners by the following combination of features: pelvic-fin rays 11; body scales covered with long, reclined, needle-like spinules densely scattered over exposed portion; underside of head almost completely naked, with prominent sensory pores; teeth in broad bands in both jaws; snout long (31–32% of head length (HL)), protruding well beyond upper jaw; second spinous ray of first dorsal fin greatly elongated (height of first dorsal fin 158–166% HL); no prominent dark band encircling trunk; first dorsal fin almost uniformly blackish. The first report of N. infranudis in the Indian Ocean represents the only confirmed record of the species since its original description. A key to species of the N. spinosa group is provided.

Key words:

• Deep-sea fish
• Nezumia spinosa group
• range extension
• Southeast Asia
• Timor Sea

Acknowledgements

We thank the following researchers and museum specialists for specimen loans and assistance during the first author's visits to their institutions: Arnold Suzumoto (BPBM), Tomio Iwamoto and David Catania (CAS), Yuhji Yamamoto and Takuya Matsuzaki (Centre for Advanced Marine Core Research, Kochi University), Alastair Graham and Peter Last (CSIRO), Mamoru Yabe, Hisashi Imamura and Toshio Kawai (HUMZ), Romain Causse (MNHN), Gento Shinohara, Takashi P. Satoh, Masanori Nakae and Keiichi Matsuura (NSMT), Jeffrey T. Williams, Ai Nonaka and G. David Johnson (USNM). Our sincere thanks go to Gordon Yearsley (Hobart, Australia) who reviewed an early draft of the manuscript and provided valuable comments.

Disclosure statement

No potential conflict of interest was reported by the authors.

Editorial responsibility: Michael Mincarone

Additional information

Funding

This work was supported by the Japan Society for the Promotion of Science, Tokyo, under a Grant-in-Aid for Scientific Research (B) [24370041]; the Kochi University under a Grant-in-Aid for the ‘Marine Science Project’ of the Natural Science Cluster (Science Unit); and the National Museum of Nature and Science, Tsukuba, under the ‘Kuroshio Sougou Project’.