Epigonus gemma

Common Name

Gem Cardinalfish

Year Described

Okamoto, Baldwin & Long, 2024

Identification

Dorsal Fin: VII-1, 9-10
Anal Fin: II, 9
Pectoral Fin: 16
Lateral Line: 43-44, plus 5-6 on caudal fin
Gill Rakers: 25-27 (first arch)
Vertebrae: 10+15 = 25 total

Body moderately slender and laterally compressed. Large terminal mouth. Teeth conical. Lingual and endopterygoid teeth absent. Enlarged teeth present at lower jaw symphysis (at all sizes). Maxillary process absent. Opercular spine absent. Lateral line complete and composed of pored scales. Two scales above and 8-9 above lateral line at mid-body. 8-9 pyloric caeca. No ribs on abdominal vertebrae. First dorsal and first anal spine tiny. Pectoral fin does not reach anus. Pelvic fin reaches about to anus. Caudal fin forked. Body fully scaled except snout tip and lower jaw. No luminous organ on belly.

Color

Purplish with a silvery sheen, grading to tan on the belly. Fins blackish. Opercle bluish-silver with a dark rear border.

Size

Maximum known size 76.7mm SL.

Habitat

Specimens collected by submersible around 300m, but likely deeper. Found on walls near crevices.

Range

Known so far only from Curacao.

References

Okamoto, M., Baldwin, C. C., & D. J. Long. 2024. Two new species of the deepwater cardinalfish genus Epigonus (Epigonidae) from deep reefs off Curaçao, southern Caribbean. Ichthyological Research, 71(3), 1–10.

Other Notes

A member of the E. pandionis group distinguished by lateral scale count, lack of opercular spine, and dorsal fin count. A combination of the enlarged teeth adjacent to the jaw symphysis, the lack of opercular spine, and meristics distinguish this from others in the genus.