Epigonus angustifrons Abramov & Manilo, 1987

Okamoto, Makoto, Chen, Wei-Jen & Motomura, Hiroyuki, 2020, New distributional records of three deepwater cardinalfishes Epigonus angustifrons, E. denticulatus, and E. exodon (Perciformes: Epigonidae) in the South Indian Ocean, Cybium 44 (2), pp. 165-168 : 165-166

Epigonus angustifrons Abramov & Manilo, 1987

( Fig. 1 ; Tab. I)

Material examined

Two specimens: CSIRO H 5408-03 (189.7 mm SL, female), CSIRO H 5408-04 (210.3 mm SL, female), 34°56.87’S, 81°11.92’E, St. Paul Seamount , central South Indian Ocean, 430-595 m depth, 1 May 1997, demersal trawl, FRV Austral Leader .

Diagnosis

Dorsal-fin rays VII-I-I, 10-11; pectoral-fin rays 19-21; total gill rakers 33-36; vertebrae 10 + 15; pyloric caeca 21-24; pored lateral-line scales 47-50 + 3-5; scales below lateral line 11; opercular spine absent; maxillary mustache-like processes absent; ribs on last abdominal vertebra present; tongue toothless; oral cavity black; body depth 18.1-19.1% SL.

Distribution

Western and central South Indian Ocean ( Okamoto and Gon, 2018; present study; Fig. 2 ) and eastern South Atlantic ( Okamoto and Gon, 2018).

(1) Marine Fisheries Research and Development Center, Fisheries Research Agency, 15F Queen’s Tower B, 2-3-3 Minatomirai, Nishi-ku, Yokohama, Kanagawa 220-6115, Japan. [[e-mail]]

(2) Institute of Oceanography, National Taiwan University, No. 1 Sec. 4 Roosevelt Rd. Taipei 10617, Taiwan. [wjchen.actinops@gmail. com]

(3) The Kagoshima University Museum, 1-21-30 Korimoto, Kagoshima 890-0065, Japan. [[e-mail]]

Remarks

The present specimens represent the first confirmed record of this species from the central South Indian Ocean. There are no clear differences in the meristic and morphometric characters between the present and previously recorded specimens. Epigonus angustifrons has an isolated dorsal-fin spine between the first and second dorsal fins and a character that makes it a member of the E. telescopus group by having the isolated dorsal-fin ray ( Abramov, 1992; Okamoto and Gon, 2018). The isolated dorsal-fin spine of the species is rarely reduced, becoming difficult to discern (e.g. CSIRO H 5408-04). In the Indian Ocean, E. angustifrons is similar to E. denticulatus in having a slender body and more than 30 gill rakers, but differs in having a black oral cavity.

Figures

Figure 1. – Epigonus angustifrons, CSIRO H 5408-04, 210.3 mm SL, central South Indian Ocean.

Figure 2. – Collection localities of Epigonus angustifrons (present study: Z; Okamoto and Gon, 2018: „), E. denticulatus (present study: Δ; Okamoto and Gon, 2018: A), and E. exodon (present study: C; Okamoto and Motomura, 2012: l) in the central and western South Indian Ocean.