Epigonus elongatus Parin & Abramov, 1986

Okamoto, Makoto & Gon, Ofer, 2018, A review of the deepwater cardinalfish genus Epigonus (Perciformes: Epigonidae) of the Western Indian Ocean, with description of two new species, Zootaxa 4382 (2), pp. 261-291 : 272-273

Epigonus elongatus Parin & Abramov, 1986

(New English name: Elongate Deepwater Cardinalfish) ( Figs. 2 , 9 ; Tables 1, 2)

Epigonus elongatus Parin & Abramov, 1986a: 55 , fig. 2 (original description; type locality: 11°00 S, 50°42 E, off Saya de Malha Bank, Western Indian Ocean, 320 m depth; holotype: ZIN 47138); Shcherbachev, 1987: 42 (list, western Indian Ocean); Abramov, 1992: 98 (key); Okamoto & Motomura, 2013: 309, fig. 9c (key and photograph).

Material examined. ZIN 47138, holotype, 160.0 mm SL, 11°00 S, 50°42 E, off Saya de Malha Bank , Western Indian Ocean, 320 m depth, 9 April 1983 ; ZIN 47139, 2 specimens, paratypes, 140.0–149.0 mm SL, same data as holotype (photographs and radiographs).

Diagnosis. Dorsal-fin rays VII-I, 10; pectoral-fin rays 18–20; total gill rakers 22–23; vertebrae 10 + 15; pyloric caeca 7–9; pored lateral-line scales 48–50; opercular spine absent; maxillary mustache-like processes absent; nublike structures or spine on symphysis of lower jaw absent; ribs on last abdominal vertebra absent; tongue toothless; orbital diameter 12.1–13.6% SL; lower-jaw length 13.4–15.1% SL; body depth 16.4–18.2% SL.

Measurements (% SL); counts are given in Table 1. Head length 31.4–32.9; head height 15.7–18.9; body depth 16.4–18.2; body width 13.6–16.1; caudal-peduncle depth 8.2–9.4; caudal-peduncle length 27.3–30.0; orbital diameter 12.1–13.6; interorbital width 9.1–10.5; postorbital length 10.0–11.9; upper-jaw length 11.4–12.8; lowerjaw length 13.4–15.1; snout length 6.9–9.4; pre-first dorsal-fin length 36.2–39.1; pre-second dorsal-fin length 57.8–61.8; pre-pectoral-fin length 31.4–35.7; pre-pelvic-fin length 33.6–35.6; pre-anal-fin length 65.0–67.8; first spine length on first dorsal fin 3.1–6.4; second spine length on first dorsal fin 4.7–6.5; second dorsal-fin spine length 8.2–10.3; second anal-fin spine length 4.7–5.7; pelvic-fin spine length 8.0–9.4; first dorsal-fin base length 10.0–11.2; second dorsal-fin base length 9.1–10.0; anal-fin base length 8.6–9.4; pectoral-fin length 12.7–15.7; pelvic-fin length 10.1–12.1.

Distribution. Off Saya de Malha Bank, Western Indian Ocean (Parin & Abramov 1986a), at 320 m depth ( Fig. 2 ).

Comparisons and Remarks. Epigonus elongatus is a member of the E. pandinonis group ( Okamoto & Motomura 2013). E. elongatus differs from the remaining 11 species of the genus in the Western Indian Ocean in having fewer gill rakers (22–23 vs. 26–36 in the others) and lacking ribs on the last abdominal vertebra. No additional specimens of E. elongatus have come to light since the original description in 1986 ( Fig. 9 ).

Figures

FIGURE 2. Distribution of three species of the Epigonus pandionis group in the Western Indian Ocean.

FIGURE 9. Epigonus elongatus, ZIN 47138, holotype, 160.0 mm SL.