[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. 
A. In 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.

  http://www.mapress.com/zootaxa/2008/f/zt01839p059.pdf

[Ichthyology • 2016] Cynoglossus nanhaiensis • A New Species of Tongue Sole (Pleuronectiformes: Cynoglossidae: Cynoglossus) from coastal waters of the South China Sea

Cynoglossus nanhaiensis 

Wang, Munroe & Kong, 2016

 DOI: 10.2988/0006-324X-129.Q2.129 

Abstract

A new tongue sole, Cynoglossus nanhaiensis, described from 21 specimens (101.0–133.7 mm SL) collected in coastal waters of the South China Sea, is distinguished from congeners by the following combination of characters: 3 ocular-side lateral lines; no blind-side lateral lines; 2 ocular-side nostrils; 8 caudal-fin rays; 49–51 total vertebrae; 64–73 scales in the midlateral line; 11–12 scales in diagonal series between midlateral and dorsal lateral lines; 99–108 dorsal-fin rays; 77–82 anal-fin rays; pores of lateral-line scales tubular, with conspicuously black tips posteriorly; and with light- to medium-brown ocular-side background coloration overlain by numerous, small, irregular, dark blotches forming a series of narrow, interrupted, longitudinal stripes, with many specimens also featuring two large, brown spots on their caudal region. Among congeners, C. nanhaiensis is most similar to C. maccullochi Norman, 1926, described from specimens taken off Queensland, Australia, but differs in its ocular-side pigmentation (conspicuous longitudinal series of irregular blotches and caudal spots absent in C. maccullochi) and body depth. Features of C. nanhaiensis are also reminiscent of those reported for C. dollfusi (Chabanaud, 1931), a poorly-known nominal species from the Red Sea, and C. itinus (Snyder, 1909), a better-known species occurring in marine waters off Japan and Southeast Asia. Cynoglossus nanhaiensis differs from both species in having two (vs. one) ocular-side nostrils. Cynoglossus itinus also lacks the series of conspicuous, darkly-pigmented, interrupted, longitudinal stripes on the ocular side that are characteristic of C. nanhaiensis. Cynoglossus nanhaiensis is further distinguished from C. dollfusi in having only a single pelvic fin (vs. two in C. dollfusi). Cynoglossus nanhaiensis occurs in coastal waters of the South China Sea off southern China and Viet Nam.

Keywords: Flatfish, Tonguefish, Cynoglossid tongue sole

Fig. 1. Cynoglossus nanhaiensis, new species, holotype (fresh condition), SCSMBC007425, male, 127.6 mm SL.
A. Ocular side. B. Blind side. (Photograph: Z.-M. Wang). 

Distribution.— Based on fishery landings, this species occurs in coastal waters off Sanya and Lingshui, Hainan Province; Zhanjiang, Guangdong Province, China; two specimens were collected off Viet Nam, one in the Gulf of Tonkin (20°46′29.99″N, 107°04′40.8″E) and the other off Phan Thiet (10°55′20″N, 108°06′34″E).

Etymology.— The name, nanhaiensis, is derived from the Chinese word, Nanhai, meaning South China Sea, in reference to localities where most specimens were collected.

Zhong-Ming Wang, Thomas A. Munroe and Xiao-Yu Kong. 2016. A New Species of Tongue Sole (Pisces: Pleuronectiformes: Cynoglossidae: Cynoglossus) from coastal waters of the South China Sea. Proceedings of the Biological Society of Washington. 129(1); 129-143. DOI: 10.2988/0006-324X-129.Q2.129