Epigonus telescopus (Risso, 1810)

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 : 283-284

Epigonus telescopus (Risso, 1810)

(English name: Black Cardinalfish; Black Deepsea Cardinal) ( Figs. 1 , 18 ; Tables 1–2)

Pomatomus telescopus Risso, 1810: 301 , pl. 9 (original description; type locality: northwestern Mediterranean Sea, Nice, France; lectotype: MNHN B-0862); Lowe, 1838: 173 (list); Capello, 1868: 160; Moreau, 1881: 386, fig. 125; Vaillant, 1888: 376 (in part).

Epigonus macrophthalmus Rafinesque, 1810: 64 (original description; type locality unknown; types unknown).

Pomatomus telescopium Cuvier, 1828: 171 (incorrect emendation of Risso, 1810); Valenciennes, 1830: 495; Valenciennes, 1837–1844: 6 pl. I; Günther, 1859: 250; Günther, 1880: 395 (brief description); Cocco, 1885: 85; Holt & Calderwood, 1895: 405, pl. LXII.

Pomatomus cuvieri Cocco, 1829: 143 (original description; type locality: Messina, Sicily, Italy, Mediterranean Sea; types unknown).

Pomatomus cuvierii: Valenciennes, 1830: 501 (incorrect emendation of Pomatomus cuvieri in Cocco, 1829 ).

Epigonus telescopus: Goode & Bean, 1896: 232 ; Barnard, 1927: 523 (key and description, South Africa); Fowler, 1936: 736, fig. 326 (description, West Africa); Mayer, 1974: 152, fig. 2: (description, Atlantic Ocean and New Zealand); Mayer, 1975: 16 (brief description, South Atlantic); Gon, 1986: 559 (key and brief description, South Africa); Tortonese, 1986: 807 (brief description, North Atlantic and Mediterranean); Shcherbachev, 1987: 42 (list, Indian Ocean); Paulin et al., 1989: 180, fig. 113.5a (key, New Zealand); Mochizuki, 1990: 262 (description and photograph, New Zealand); Abramov, 1992: 98 (list); Gomon et al., 1994: 562 (key, Australia); Santos et al., 1997: 83 (list, Azores); Arruda, 1997: 82 (list, Azores); Saldanha & Biscoito, 1997: 199 (brief description, Mid-Atlantic Ridge); Bianchi et al., 1999: 166, pl. XI (Namibia); Biagi et al., 2002: (list, Mediterranean); Bilecenoglu et al., 2002: 81 (list, Turkey); Moore et al., 2003: 226 (list, western North Atlantic); Sartor et al., 2003: 278 (list, Mediterranean); Mytilineou et al., 2005: 231 (list, Ionian Sea); Hoese et al., 2006: 1115 (synonyms and distribution, Australia); Fricke et al., 2007: 82 (list, Turkey); Gomon et al., 2008: 564 (key and photograph, Australia); Bañon et al., 2010: 16 (list, Galicia); Møller et al., 2010: 58 (list, Greenland); Stewart & Gon, 2015: 1226 (key and description, New Zealand); Bañon et al., 2016: 322 (list, Galicia); Gon, 2016: 2434 (key and distribution, eastern Central Atlantic); Okamoto, 2016b: 74 (description and photograph).

Material examined. AMS I.28165-001, 3 specimens, 112.4–187.9 mm SL, 33°35´17˝S, 44°09´33˝E, Walters Shoal, western South Indian Ocean , 750 m depth, 18 December 1988 ; USNM 307603 , 201.2 mm SL, 33°43´42˝S, 43°61´58˝E, Walters Shoal , western South Indian Ocean, 1,000–1,030 m depth, 17 December 1988 ; USNM 307608 , 2 specimens, 137.8–154.3 mm SL, 33°37´42˝S, 44°10´42˝E, Walters Shoal, western South Indian Ocean , 750–775 m depth, 18 December 1988 ; unretained specimen, 720 mm SL, western South Indian Ocean .

Diagnosis. Dorsal-fin rays VII-I-I, 10; pectoral-fin rays 19–23; total gill rakers 23–26; vertebrae 11 + 14; pyloric caeca 21–34; pored lateral-line scales 46–50 + 3–5; opercular spine absent; maxillary mustache-like processes absent; ribs on last abdominal vertebra present; tongue toothless; body depth 22.7–25.5% SL.

Measurements (% SL); counts are given in Table 1. Head length 32.4–38.0; head width 16.8–19.2; head height 17.3–20.8; body depth 22.7–25.5; body width 15.9–18.9; caudal-peduncle depth 7.8–11.0; caudal-peduncle length 22.6–26.3; orbital diameter 8.8–17.1; interorbital width 9.9–11.2; postorbital length 11.1–15.2; upper-jaw length 13.7–15.5; lower-jaw length 15.1–19.1; snout length 7.3–9.7; pre-first dorsal-fin length 38.0–42.0; presecond dorsal-fin length 59.3–61.9; pre-pectoral-fin length 33.5–36.9; pre-pelvic-fin length 36.3–39.9; pre-anus length 60.9–66.3; pre-anal-fin length 67.2–70.7; first spine length on first dorsal fin 4.6–5.8; second spine length on first dorsal fin 11.9–12.9; third spine length on first dorsal fin 13.9–15.7; second dorsal-fin spine length 5.2–8.9; first anal-fin spine length 1.8–2.8; second anal-fin spine length 5.1–8.9; pelvic-fin spine length 7.5–12.1; first dorsal-fin base length 12.4–17.2; second dorsal-fin base length 9.8–11.1; anal-fin base length 8.3–13.0; pectoral-fin length 11.0–16.6; pelvic-fin length 13.3.

Distribution. Western South Indian Ocean (Shcherbachev 1987; Abramov 1992; present study); Eastern Atlantic including Mediterranean ( Mayer 1974, 1975; Abramov 1992); western North Atlantic ( Mayer 1974); Australia ( Hoese et al. 2006; Gomon et al. 2008); New Zealand (Paulin et al. 1989; Stewart & Gon 2015), at ca. 75–1375 m depth.

Comparisons and Remarks. Epigonus telescopus belongs to the E. telescopus group by having an isolated dorsal-fin spine between first dorsal and second dorsal fins. The isolated dorsal fin spine reduces in size with growth, becoming difficult to discern in large adult specimens ( Fig. 18 ). This species is similar to E. angustifrons in having the isolated dorsal-fin spine, but differs in having 23–26 gill rakers (vs. 33–36 in E. angustifrons ) and a deeper body (ca. 1/4 of SL vs. ca. 1/5 of SL in E. angustifrons ). Furthermore, E. telescopus differs from other congeners in the Western Indian Ocean in the absence of an opercular spine (vs. pungent opercular spine present in E. bispinosus , E. idai , E. lenimen , E. marimonticolus , E. pectinifer , E. robustus , and E. waltersensis ) and 11 + 14 vertebrae (vs. 10 + 15 in E. denticulatus , E. elongatus , E. exodon , E. macrops , and E. marisrubri ). Epigonus telescopus is the largest species of the genus (85 cm in total length) and long-lived with a maximum age about 100 years ( Dunn 2009). In some area, this species is utilized commercially ( Okamoto 2016b).

Figures

FIGURE 1. Distribution of four species of the Epigonus oligolepis group and the E. telescopus group in the Western Indian Ocean.

FIGURE 18. Epigonus telescopus, A: AMS I.28165-001, 1 of 3 specimens, 112.4 mm SL; B: USNM 307603, 201.2 mm SL; C: uncatalogued specimen, 720 mm SL.