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| Epinephelus randalli Hoshino, Senou & Nguyễn, 2024 |
Abstract
The epinephelid longtooth grouper comprises two nominal species, Epinephelus bruneus Bloch, 1793 and E. moara (Temminck and Schlegel, 1843). The name E. moara had been applied to specimens in Japan, Taiwan, and South Korea, but was later relegated to the junior synonymy of E. bruneus. However, in continental China, two forms of longtooth groupers have been recognized: one distributed in the South China Sea (herein the “southern form”) and another in the East and South China Seas (the “northern from”). The name E. bruneus has been applied to the former, and E. moara to the latter. A recent study demonstrated that the two forms were morphologically and genetically distinct. However, because that study did not examine the name-bearing types, the appropriate scientific names remained uncertain. Examinations herein of the lectotypes and the original illustrations for the descriptions of E. bruneus and E. moara, and comparisons of specimens of both forms, revealed that both lectotypes were conspecific with the “northern form”; therefore, the valid name for this form is E. bruneus, again relegating E. moara to its junior synonymy. The “southern form” is described herein as E. randalli sp. nov., which is distinguished from E. bruneus by fewer dorsal-fin soft rays (13–14, usually 13 vs. 14–16, usually 15), the size and number of enlarged serrae at the corner of the preopercle (abruptly and remarkably enlarged, 2–4 vs. gradually and slightly enlarged, 2–11, usually 4–7), the scales on the side of body (cycloid except pectoral region vs. mostly ctenoid), and the patterns of the body bars and the head bands. The use of these correct scientific names will greatly assist communication regarding the appropriate development of stock management, aquaculture, and conservation of these commercially important groupers.
Keywords: Epinephelus randalli, longtooth grouper, mud grouper
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| Epinephelus bruneus. a, KAUM–I. 80316, 224.7mm SL, Japan; b, KPM-NI 26963, 120.2mm SL, Japan; c, KPM-NI 35270, 769mm SL, Japan. |
Epinephelus bruneus Bloch, 1793
[English name: Longtooth Grouper;
standard Japanese name: Kue]
Diagnosis. Epinephelus bruneus can be distinguished
from the congeners by the combination of following characters: serrae at angle of preopercle gradually and weakly enlarged from dorsal to ventral direction, 2–11 (usually 4–7)
(Fig. 4a–c); dorsal-fin soft rays 14–16 (usually 15) (Table 1);
anal-fin soft rays 8–9 (Table 1); caudal fin rounded; scales
on lateral body ctenoid; back and side with six irregular
broad oblique transverse bars, second bar directed forward becoming nearly horizontal ventral to lateral line and
reaching opercular margin only dorsal to its posterior tip
(Figs 1, 5a); third bar with an anterior branch connecting
with second bar and reaching opercular margin (Figs 1, 5a);
fourth band of head broader than eye diameter (Fig. 5e).
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| Second and third bars of body (a–d) and fourth bar of head (e–g) of Epinephelus bruneus (= “northern form”) and Epinephelus randalli sp. nov. (= “southern form”). a, e, Epinephelus bruneus, KAUM–I. 80316, 224.7mm SL, Japan; b, f, E. randalli sp. nov., NSMT-P 66257, 143.3mm SL, Vietnam, holotype; c, g, original illustration for description of E. bruneus (Bloch 1793); d, original illustration for description of Serranus moara (Temminck and Schlegel 1843). Downward arrow, second bar of body ventral to lateral line; upward arrow, anterior branch of third bar of body; rectangle, fourth bar of head. |
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| Epinephelus randalli sp. nov. a, NSMT-P 66257, holotype, 143.3mm SL, Hai Phong, Vietnam; b, NSMT-P 68411, paratype, 334mm SL, Long Chau Bay, Vietnam; c, FRLM 49723, paratype, 177.6mm SL, Ha Long, Vietnam. a, b, Images of preserved specimens; c, an image of a fresh specimen. |
Epinephelus randalli sp. nov.
[English name: Mud Grouper;
new standard Japanese name: Minami-kue]
Diagnosis. Serrae at angle of preopercle abruptly and remarkably enlarged from dorsal to ventral direction (Fig. 4d–f); dorsal-fin soft rays 13–14; scales on lateral body cycloid except ctenoid at pectoral region; back and side with six oblique transversal bars, second bar steeply oblique not becoming nearly horizontal ventral to lateral line, reaching opercular margin dorsal to and ventral to its posterior tip (Figs 5b, 7); third bar on body without an anterior branch (Figs 5b, 7); fourth band on head very narrow, much narrower than diameter of pupil (Fig. 5f).
Etymology. The specific name randalli is named in honor of the distinguished ichthyologist late Dr. John E. Randall, who passed away in 2020.
In the new standard Japanese name, Minami-kue, “minami” is “south” or “southern” in Japanese, and “kue” is the Japanese name of the longtooth grouper.
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| Illustrations of Epinephelus randalli sp. nov. that are misidentified in references. a, Illustration in Jordan and Seale (1905: pl. 5) as “Epinephelus moara”; b, illustration in Fowler (1931: fig. 4) as “Serranus fasciatomaculatus”. |
Kouichi Hoshino, Hiroshi Senou and Quân Văn Nguyễn. 2024. Taxonomic Status of the Commercially Important Grouper, Epinephelus bruneus and E. moara (Osteichthys: Perciformes: Epinephelidae), with the Redescription of E. bruneus and the Description of a New Species. Species Diversity. 29(2); 389-407. DOI: doi.org/10.12782/specdiv.29.389
