A review of the deepwater cardinalfish genus Epigonus (Perciformes: Epigonidae) of the Western Indian Ocean, with description of two new species

The fishes of the genus Epigonus Rafinesque, 1810 in the Western Indian Ocean (including the Red Sea and the Gulf of Aden) are reviewed. Twelve species of the genus are recognized: Epigonus angustifrons Abramov & Manilo, 1987; E. denticulatus Dieuzeide, 1950; E. elongatus Parin & Abramov, 1986; E. exodon Okamoto & Motomura, 2012; E. lenimen (Whitley, 1935); E. macrops (Brauer, 1906); E. marimonticolus Parin & Abramov, 1986; E. marisrubri Krupp, Zajonz & Khalaf, 2009; E. pectinifer Mayer, 1974; E. robustus (Barnard, 1927); E. telescopus (Risso, 1810); E. waltersensis Parin & Abramov, 1986, and two new species, E. bispinosus n. sp. and E. idai n. sp. Epigonus bispinosus and E. idai belong to the E. constanciae group, defined as having a pungent opercular spine, more than 45 pored lateral-line scales, and lacking an isolated dorsal fin spine between the first- and second dorsal fins. Epigonus bispinosus differs from other members of the group in having two small spines on the symphysis of lower jaw, a pair of ribs on the last abdominal vertebra, 10 + 15 vertebrae, 31–33 gill rakers and lacking a maxillary mustache-like process. Epigonus idai differs from other members of the group in having a pair of ribs on the last abdominal vertebra, 4–5 tiny projections present on symphysis of lower jaw, 10 + 15 vertebrae, strongly ctenoid scales, and 28–29 gill rakers, and in lacking a maxillary mustache-like process. A key to the species, photographs, diagnoses, and distributions in the Western Indian Ocean are given.

Epigonus exodon, a new species of deepwater cardinalfish (Teleostei: Perciformes: Epigonidae) from Réunion, western Indian Ocean

A new species of deepwater cardinalfish, Epigonus exodon, is described based on two specimens, 97.0–60.2 mm standardlength, from Réunion (depth 450–480 m), western Indian Ocean. Epigonus exodon belongs the Epigonus oligolepis group,defined as having seven spines on the first dorsal fin, one spine and 10 soft rays on the second dorsal fin, 35–37 poredlateral-line scales to the end of the hypural and lacking an opercular spine and ribs on the last abdominal vertebra. It differsfrom other members of the group in having a narrow tongue, a shallow V-shaped tooth patch on rear two-thirds of tongue, anteriorly projecting teeth on each side of the symphysis of lower jaw, and 26–28 total gill rakers.