Parascombrops nakayamai Schwarzhans & Prokofiev 2017


Holotype of Parascombrops nakayamai, BSKU 102255, 97-mm-SL. Source: . License:

Summary:
A slender ocean bass with a flat dorsal head profile, a sharply-pointed snout, a V-shaped vomer with reduced dentition and only few long teeth near the sides of the base, and no longitudinal ridges on the preopercular lobe. The species has a black tip on the first dorsal fin, a pale mouth with a patch of large melanophores on the mouth roof, and a dark gill cavity and peritoneum.

Cite this page as:
Bray, D.J. 2018, Parascombrops nakayamai in Fishes of Australia, accessed 13 Nov 2024, https://fishesofaustralia.net.au/home/species/5324

Parascombrops nakayamai Schwarzhans & Prokofiev 2017

More Info


Distribution

Off northern Western Australia (18 53 S, 116 10 E) and the Timor Sea (09 34 S, 128 08 E) in depths of 295-450 m. Elsewhere the species is widely distributed in the Western Pacific: southern Japan, Taiwan, northern Philippines, New Caledonia, Vanuatu and Wallis and Futuna Islands, at depths of 216-794 m.

Features

Dorsal fin IX; I, 8–9; Anal fin II, 7; Pelvic fin I, 5; Pectoral fin 15–17; Gill rakers (developed) 11–14 (up to 16 in specimens smaller than 60 mm SL); Pseudobranchial filaments 20–29 (down to 16 in specimens smaller than 60 mm SL); Lateral line scales about 25–27. 
Morphometrics (% of SL): orbit 10.0 (9.5–12.6); snout 9.8 (9.5–11.5, down to 8.0 in specimens smaller than 60 mm SL); head length 39.5 (37.5–42.6); pectoral length 22.5 (19.5–24.3); maximal body depth 24.5 (20.9–25.6); predorsal length 39.8 (38.2–42.6); preventral length 36.6 (32.5–38.3); preanal length 68.2 (59.4–68.8). 
Snout long, sharply pointed; interorbital space almost flat. Posterior edge of maxillary concave with postero-dorsal and postero-ventral angles broadly rounded and postero-ventral angle extended downward and slightly backward resulting in slightly oblique posterior rim of maxillary (much less developed in small specimens, which possess a posteroventral angle only slightly extended downward, and an almost vertical posterior rim of the maxillary plate). Preopercular lobe without longitudinal ridges, but denticles of hind margin serration extending into well-developed crests on preopercular lobe; inner edge of preopercle with 2–5 denticles. 
Proximal-middle radial of first anal fin pterygiophore long, slightly curved distally, with moderately broad hollow tip, reaching parapophyses of last abdominal vertebra. First haemal spine with weak posterior expansion. Pelvic fin spine serrated along its outer edge; all other fin spines smooth.

Colour

In Preservative: uniformly pale with the upper half of head including snout and anterior portion of lower jaw dark; upper half of trunk, remainder of head and fins with numerous small dotted evenly distributed melanophores; large melanophores along lateral line pores. First dorsal fin with black tip over first three to four spines. Mouth pale, with patch of large melanophores on roof of mouth. Branchial cavity and peritoneum dark.

Similar Species

Parascombrops nakayamai is best recognized by the slender head and sharply pointed snout, about as long as the orbital diameter, the reduced dentition on the vomer, and the ectopterygoid being wider, slightly spatulate, and with more teeth rows (3–4) than the palatine (1–2). Smaller specimens (75–90 mm of SL) tend to have 1 or 2 rows of granular teeth on the vomer, while in larger specimens this is reduced to a few isolated granular teeth or none. The dentition pattern is only shared with P. yamanouei n. sp., which however differs in a less slender body, maximal body depth 28–34% SL; mean 31.5% SL, (vs 23–27% SL; mean 24.3% SL), the snout shorter than the orbit (vs equally long), and the compressed otoliths OL:OH = 1.5–1.6 (vs 1.7–1.8). Parascombrops nakayamai resembles closest P. argyreus and P. philippinensis. In addition, it differs from P. argyreus in the absence of longitudinal ridges on the preopercular lobe, the lower number of gill rakers in specimens of comparable size ( Fig. 21 View Figure ) and the greater head length (37.9–42.6% SL vs 32.6–38.3% SL). It can be distinguished from P. philippinensis by the lower number of gill rakers, 11–15 (vs 15–18).

Etymology

Named in honour of Naohide Nakayama (Laboratory of Marine Biology, Faculty of Science, Kochi University, Japan), who was the first to recognize the difference of this species from P. philippinensis, based on a specimen collected from Tosa Bay, Japan.

Species Citation

Parascombrops nakayamai Schwarzhans & Prokofiev 2017, Zootaxa 4260 (1): 39, Figs. 7F, 8C, 9F, 12B, 13F, 14O-R, 21, 27. Type locality: Japan, Tosa Bay, Mimase fish market near Kochi.

Author

Bray, D.J. 2018

Parascombrops nakayamai Schwarzhans & Prokofiev 2017

References


Schwarzhans, W.W. & Prokofiev, A.M. 2017. Reappraisal of Synagrops Günther, 1887 with rehabilitation and revision of Parascombrops Alcock, 1889 including description of seven new species and two new genera (Perciformes: Acropomatidae). Zootaxa 4260 (1): DOI: 10.11646/zootaxa.4260.1.1

Quick Facts


Depth:216-794 m

Max Size:11 cm SL

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