Epigonus pectinifer Mayer, 1974

Okamoto, Makoto, 2018, First Records of Two Deepwater Cardinalfishes (Perciformes: Epigonidae), Epigonus lifouensis and E. pectinifer, from Indonesia, Eastern Indian Ocean, Species Diversity 23, pp. 243-248 : 245-246

Epigonus pectinifer Mayer, 1974 ( Fig. 3 ; Table 1)

Epigonus pectinifer Mayer, 1974: 186 , fig. 19 (original description; type locality: 12°01′N, 61°53.5′W, Caribbean west of Grenada, 378–450 m depth; holotype: USNM 207725); Mochizuki and Shirakihara 1983: 205, fig. 5b (list and photograph, Japan); Mochizuki 1984: 146, pl. 133-O (brief description and photograph, Japan); Machida 1985: 482 (description and photograph, Okinawa Trough, Japan); Parin and Abramov 1986: 186 (description, Caribbean Sea, New Zealand, central North Pacific); Abramov 1992: 99 (key); Hayashi 1993: 683 (key, Japan); Mochizuki 1997: 306 (brief description and photograph, Japan); Shinohara and Matsuura 1997: 303 (list, Suruga Bay, Japan); Hayashi 2000: 781 (key, Japan); Shinohara et al. 2001: 324 (Tosa Bay, Japan); Hayashi 2002: 781 (key, Japan); Moore et al. 2003: 225, fig. 39 (record, near Norfolk, Baltimore, and Hudson canyons, off the New England region); Gon 2003: 1393 (key, western central Atlantic); Shinohara et al. 2005: 432 (list, Ryukyu Islands, Japan); Mundy 2005: 359 (list, Emperor Seamounts); McEachran and Fechhelm 2005: 242 (Gulf of Mexico); Okamoto and Fukui 2011: 391 (key); Okamoto 2012: 252 (key); Hayashi 2013: 865 (key, Japan); Stewart and Gon 2015: 1219 (key, New Zealand); Okamoto and Gon 2018: 280 , fig. 16 (south west Indian Ocean).

Epigonus robustus (not of Barnard): Kuroda 1951: 331 (list, Suruga Bay, Japan); Kamohara 1964: 39 (list, Tosa Bay, Japan).

Material examined. HUMZ 190275 , 67.1 mm SL, sex indeterminate, 08°10′3″S, 109°49′3″E – 08°09′4″S, 109°48′8″E, off Java, Indonesia, 280–285 m depth, 13 September 2004 .

Diagnosis. A species of Epigonus with the following combination of characters: dorsal-fin rays VII-I, 9; pectoral- fin rays 15–18; total gill rakers 26–30; vertebrae 10+15; pyloric caeca 5–7; pored lateral-line scales 45–51+3–5; pungent opercular spine present; pointed maxillary mustachelike processes present; ribs on last abdominal vertebra present; slender tooth patch present on posterior half of tongue; pectoral fin not reaching a vertical line from anus.

Distribution. Known from the south western Indian Ocean ( Okamoto and Gon 2018); Indonesia (present study); western North Atlantic ( Moore et al. 2003); Gulf of Mexico ( Mayer 1974; McEachran and Fechhelm 2005); Caribbean Sea ( Mayer 1974); Tasman Sea, Australia and New Zealand ( Parin and Abramov 1986; Abramov 1992; Okamoto 2012; Stewart and Gon 2015); Emperor Seamounts ( Parin and Abramov 1986; Abramov 1992; Mundy 2005); and Japan ( Machida 1985; Hayashi 2013), at 99–750 m depth.

Remarks. In a recent taxonomic study of the genus Epigonus in the western Indian Ocean, E. pectinifer has been reported from the study area for the first time ( Okamoto and Gon 2018). Also, this species has been known from the western North Atlantic, western Pacific, and the Emperor Seamounts ( Mayer 1974; Abramov 1992; Mundy 2005). The present specimen from Indonesia represents the first record of E. pectinifer from the eastern Indian Ocean ( Fig. 2 ).

Epigonus pectinifer belongs to the E. constanciae group of Okamoto (2012) due to having a pungent opercular spine. The species group comprises 21 species ( Okamoto 2015, 2016), including E. pectinifer : E. affinis Parin and Abramov, 1986 ; E. atherinoides (Gilbert, 1905) ; E. bispinosus Okamoto and Gon, 2018 ; E. chilensis Okamoto, 2012 ; E. constanciae (Giglioli, 1880) ; E. crassicaudus de Buen, 1959 ; E. ctenolepis Mochizuki and Shirakihara, 1983 ; E. draco Okamoto, 2015 ; E. elegans Parin and Abramov, 1986 ; E. heracleus Parin and Abramov, 1986 ; E. idai Okamoto and Gon, 2018 ; E. lenimen (Whitley, 1935) ; E. machaera Okamoto, 2012 ; E. marimonticolus Parin and Abramov, 1986 ; E. mayeri Okamoto, 2011 ; E. meglops (Smith and Radcliffe in Radcliffe, 1912); E. occidentalis Goode and Bean, 1896 ; E. robustus (Barnard, 1927) ; E. thai Prokofiev and Bussarawit in Parin et al., 2012; and E. waltersensis Parin and Abramov, 1986 . Of these, E. pectinifer is similar to E. constanciae in having a lingual tooth patch and a sharp-pointed maxillary mustache-like process; however, the former is distinguished from the latter in lacking a tubercle on the outer symphysis of lower jaw and having a pair of ribs on the last abdominal vertebra (vs. a small tubercle present on the outer symphysis of lower jaw and ribs absent on the last abdominal vertebra in E. constanciae ). Although E. mayeri also has a sharp-pointed maxillary mustache-like process and a pair of ribs on the last abdominal vertebra, it differs from E. pectinifer in having a longer pectoral fin (22.2–23.0% SL vs. 17.4–20.9% SL, and reaching to vertical line from anus vs. not reaching vertical line from anus in E. pectinifer ), a larger orbital diameter (16.4–17.0% SL vs. 12.1–15.4% SL in E. pectinifer ), a longer lower jaw (16.7–17.0% SL vs. 12.1–15.6% SL in E. pectinifer ), and lacking a lingual tooth patch (vs. present in E. pectinifer ).

In the check list of the species composition of the demersal ichthyofauna on the continental slope off Western Australia, eastern Indian Ocean by Williams et al. (1996), they listed three species of Epigonus : E. macrops (Brauer, 1906) , E. occidentalis , and E. robustus . However, I re-examined the specimens originally identified as E. occidentalis by Williams et al. (1996) and re-identified them as E. atherinoides (CSIRO H 2557-13, CSIRO H 2603-01, CSIRO H 2603-02; see Okamoto 2016). Deepwater cardinalfishes of the eastern Indian Ocean are represented by 10 species ( Abramov 1992; Williams et al. 1996; Okamoto and Aungtonya 2013; Okamoto and Motomura 2013; Okamoto 2016), including the first records of E. lifouensis and E. pectinifer here reported; the other 8 species are E. atherinoides , E. denticulatus , E. lenimen , E. macrops , E. robustus , E. telescopus (Risso, 1810) , E. thai , and E. tuberculatus .

Comparative material. Epigonus atherinoides: CSIRO H 2557 -13, 3 specimens, 106.7–138.3 mm SL, 23°41′6″S, 112°35′5″E – 23°42′9″S, 112°35′9″E, west of Cape Farquhar, Western Australia, 612–620 m depth, 26 January 1991; CSIRO H 2603-01, 122.2 mm SL, 31°16′2″S, 114°50′2″E – 31°16′8″S, 114°50′3″E, southwest of Ledge Point, Western Australia, 613–614 m depth, 9 February 1991; CSIRO H 2603-02, 96.3 mm SL, same data as CSIRO H 2603-01. Epigonus denticulatus: FAKU 144807, 50.7 mm SL, off Ibaraki Prefecture, Japan, 18 November 2016; KPM- NI 24857 , 96.5 mm SL, off Heda, Suruga Bay , Shizuoka Prefecture, Japan, 29 November 2009; KPM-NI 41603, 112.2 mm SL, 34°48′25″N, 138°30′36″E, Suruga Bay, Shizuoka Prefecture, Japan, 1 November 2016; KPM-NI 42646 , 85.5 mm SL, 34°18′38″N, 137°23′10″E, Enshu-nada Sea, Shizuoka Prefecture, Japan, 329–385 m depth, 9 December 2016 . Epigonus lifouensis: MNHN 2000 -0018, holotype, 139.7 mm SL, male, 21°40′59″S, 167°31′59″E, south of Lifou Island , Loyalty Islands, New Caledonia, western South Pacific , 575 m depth, 21 February 1989; MNHN 2003-1826 , paratype, 202.5 mm SL, female, 21°23′31″S, 167°46′10″E, south of Lifou Island, Loyalty Islands, New Caledonia, western South Pacific, 500 m depth, 23 February 1989; NTUM 13374 , 175.0 mm SL, 16°03′N, 113°54′E, seamount nearby the Macclesfield Bank, South China Sea, 356–410 m depth, 27 July 2015 . Epigonus pectinifer: KPM-NI 40138, 106.5 mm SL, off Heda , Suruga Bay , Shizuoka Prefecture, Japan, 9 May 2015; KPM-NI 41541 , 80.2 mm SL, off Heda, Suruga Bay, Shizuoka Prefecture, Japan, 20 November 2016; SAIAB 86380 , 3 specimens, 138.4–152.6 mm SL, 11°02′32″S, 50°35′29″E, off northern Madagascar, western Indian Ocean, 331–339 m depth, 27 September 2008; SAIAB 98893 , 7 specimens, 50.8–64.7 mm SL, 12°41′43″S, 40°40′10″E, Comoro Is ., western Indian Ocean , 292 m depth, 23 November 2007; SAIAB 193895 , 4 specimens, 80.0– 82.3 mm SL, 12°48′51″S, 40°45′69″E, off northern Mozambique, western Indian Ocean, 420–536 m depth, 15 February 1992 .

Figures

Fig. 3. Epigonus pectinifer, HUMZ 190275, 67.1mm SL, from off Java, Indonesia.

Fig. 2. Distributional records of Epigonus lifouensis (stars) and E. pectinifer (circle) in the eastern Indian Ocean.