Sunday, October 30, 2016

[Ichthyology • 2008] Symphurus thermophilus • A New Western Pacific Tonguefish (Pleuronectiformes: Cynoglossidae): The First Pleuronectiform discovered at active Hydrothermal Vents


Symphurus thermophilus  
  Munroe & Hashimoto, 2008

Abstract

Symphurus thermophilus n. sp., described from 16 specimens collected by submersibles, ROV, epibenthic sled and dredge, occurs on a variety of substrata at several active hydrothermal sites located at 239–733 m between 21°N and 35°S in the western Pacific Ocean. Symphurus thermophilus, the only pleuronectiform fish known to inhabit hydrothermal vent areas, is characterized by the combination of a 1–2–2–2–2 pattern of interdigitation of dorsal proximal pterygiophores and neural spines, 14 caudal-fin rays, 5 hypurals, 9 abdominal vertebrae, 47–51 total vertebrae, 88–94 dorsal-fin rays, 74–80 anal-fin rays, 100–112 scales in longitudinal series, ocular-side pigmentation pattern featuring 5–8, black, mostly incomplete crossbands, uniformly white blind side, and black peritoneum. Of specimens examined, seven including the holotype, were collected on Kaikata Seamount off southern Japan; one specimen was collected at the Kasuga-2 hydrothermal vent, Marianas Islands; and six were collected at sites on the Kermadec Ridge. In addition to specimens captured, many other S. thermophilus were observed from submersibles and ROVs at hydrothermal sites in the western Pacific including those in the Marianas Islands, at Nikko Seamount near Minami-Iohjima Island, and at Minami-Ensei Knoll, Mid-Okinawa Trough. Many of the specimens examined have skeletal anomalies including fused bones in the caudal skeleton, and missing or partially developed and/or misshapen fin rays.

Key words: flatfish, Symphurus, hydrothermal vents


Symphurus thermophilus    Munroe & Hashimoto, 2008 

FIGURE 3. Photographs of the hydrothermal vent tonguefish, Symphurus thermophilus
AIn situ photograph of S. thermophilus observed at Rumble 3 site, western Pacific, an area where this species occurs in high abundance. B. In situ photograph of S. thermophilus (most individuals <10 cm TL) observed at Daikoku Seamount, western Pacific, an area where this species occurs in high abundance. C. Photo of recently captured juvenile S. thermophilus taken at the Barnacle Boulders site at Kasuga-2, Mariana Islands. 


Figures 3A–C provided courtesy of NOAA’s Ocean Exploration Program and available from oceanexplorer.NOAA.gov  and oceanexplorer.NOAA.gov/explorations (Accessed 3 June 2008)


Thomas A. Munroe and Jun Hashimoto. 2008. A New Western Pacific Tonguefish (Pleuronectiformes: Cynoglossidae): The First Pleuronectiform discovered at active Hydrothermal Vents.  Zootaxa. 1839; 43–59.

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