Epigonus idai

description

Description. Counts and measurements of holotype and paratype are shown in Tables 1 – 3. Body elongate, laterally compressed, deepest at pectoral-fin base; nape not humped. Head large, broad. Maxillary mustache-like processes absent. Snout short and round, length slightly longer than interorbital width; nostrils closely set at level of upper edge of pupil, anterior nostril without membranous tube, posterior nostril elliptical without dermal flap. Eye large, round, orbital diameter greater than postorbital length; bony rim of orbit slightly raised above dorsal profile; interorbital region broad, concave at center of posterior half. Mouth large, terminal; gape oblique; posterior margin of maxilla not extending to below center of pupil; lower jaw not projecting when mouth closed; tiny 4 – 5 projections present on symphysis of lower jaw (Fig. 6 B). Teeth minute, arranged in 2 – 3 rows on anterior half of premaxilla and dentary, a single row on posterior half of both bones. Small number of minute teeth present on vomer and palatine. Basihyal toothless. Opercular spine strong, pungent, forming ridge; posterior corner of preopercle weakly serrated. Origin of first dorsal fin above anterio

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

diagnosis

Diagnosis. A species of Epigonus with the following combination of characters: dorsal-fin rays VII-I, 10; pectoral-fin rays 18 – 19; total gill rakers 28 – 29; vertebrae 10 + 15; pyloric caeca 10 – 12; pored lateral-line scales 48 – 49 + 3; scales strongly ctenoid; scales below lateral line 10; pungent opercular spine present; maxillary mustache-like process absent; ribs on last abdominal vertebra present; and 4 – 5 tiny projections present on symphysis of lower jaw.

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

distribution

Distribution. The holotype and paratype were collected off Mozambique, western South Indian Ocean (Fig. 3), at a depth of 709 – 721 m.

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

etymology

Etymology. The specific name is in honor of Dr Hitoshi Ida (Professor Emeritus, Kitasato University, School of Marine Biosciences) for his contribution to Epigonus (see Ida et al., 2007) and other percoid studies in the Indo- Pacific region. Comparisons and Remarks. Epigonus idai belongs to the E. constanciae group by having a pungent opercular spine (Okamoto 2012). Epigonus idai is unique in this species group in having 4 – 5 tiny projections on the symphysis of lower jaw (Fig. 6 B). In addition to the diagnostic characters, E. idai differs from 20 species of the group in having 10 + 15 vertebrae (vs. 11 + 14 in E. chilensis, E. crassicaudus, E. heracleus, E. lenimen, E. machaera, E. robustus), 10 soft rays on the second dorsal fin (vs. 9 soft rays in E. affinis, E. elegans, and E. waltersensis), 28 – 29 gill rakers (vs. 20 – 26 in E. atherinoides, E. ctenolepis, E. draco, E. megalops, E. okamotoi, E. occidentalis), a pair of ribs on the last abdominal vertebra (vs. absent in E. marimonticolus and E. thai), and lacking a pair of maxillary mustache-like processes (vs. a sharp-pointed maxillary mustache-like processes present in E. constanciae, E. mayeri, and E. pectinifer). The dia

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