Ophidion selenops

FamilyScientific NameAuthorYearCommon Name
OphididaeOphidion selenopsRobins and Böhlke1959Mooneye Cusk-eel

Family Ophididae — Moderately elongate ophidiiform fishes (size from about 10 to 200 cm). Anterior nostril placed midway between upper lip and posterior nostril. Supramaxilla present. Teeth usually small, densely distributed, and blunt-tipped. Very seldom fewer than 7 long gill rakers on anterior gill arch (except in Ophidiini). Dorsal and anal fins long, joined to caudal fin; dorsal-fin rays normally longer than opposing anal-fin rays; pelvic-fin rays 0-2. Scales present. A well-developed spine on opercle usually present. Anus placed posterior to tip of pectoral fin except in species with prolonged pectoral fins.

Subfamily Ophidiinae — No barbels on snout and chin. Main body of ventral arm of cleithrum meeting its mate at about level of preopercle, but a slender, elongate filament of bone extends anteriorly to pelvic fins inserted beneath eye. Median basibranchial tooth patches present or absent.

Tribe Ophidiini — At least some body scales (frequently all) non-overlapping, arranged in a basket-weave or anguilloid fashion. Head entirely or mostly naked.

All Ophidion – Head entirely naked. Ethmoid spine absent, weakly developed, or long, sharp and projecting forward to or toward snout tip.

Ophidion selenops

Unique Characters: A small species very similar to Ophidion nocomis in form, coloration, anterior scalation, and length of ventral fins. 123-129 anal rays; 132-140 dorsal rays; and 15 or 16 pectoral rays. Gill rakers 7. Palantine teeth biserial, at least in larger specimens.

Similar Species:

Bank Cusk-eel Ophidion holbrooki

Longnose Cusk-eel Ophidion antipholus

Letter Opener Ophidion nocomis

Ophidion holbrooki
Bank Cusk-eel – Ophidion holbrooki

Bank Cusk-eel Ophidion holbrooki. Head and body tan, unmarked except for dark margin to dorsal fin and, occasionally, anal fin. Gill raker on first arch with 2 rudiments on upper limb and 4 developed rakers on lower limb. Mouth subterminal. Dorsal profile nearly straight from snout to dorsal-fin origin (not arched). Body distinctly deepest at dorsal-fin origin. Body slab-sided.

Longnose Cusk-eel Ophidion antipholus. Consistently 7 branchiostegal rays and 9 caudal-fin rays (4 above, 5 below). 2 rudimentary gill rakers on upper arm of first gill arch; 5 or 6 (rarely 7) de\eloped (but short) rakers (rarely 4) on lower arm for total of 7 or 8 (rarely 6 or 9). Head scaleless. Scales on the body small, arranged in a basket- weave or anguiliform pattern. Body shape distinctive: dorsal and ventral profiles parallel for most of their length; snout prominent, protruding beyond distinctly inferior mouth. Pelvic rays short, longer one reaching under anterior edge of opercle to mid-opercle. Ethmoid spine prominent, stout, projecting forward, but short without sharp hook-like forward process. Head and body pale brown without pattern; outer border of dorsal and anal fins black, best developed in larger specimens and in anal fin and, to a lesser extent, anteriorly in dorsal fin.

Letter Opener Ophidion nocomis. A small, slender, pallid cusk eel with long ventral rays (inner of each decidedly longer than pectoral fin). Head and nape naked. Scales small, cycloid, elongate and Anguilla-like in arrangement on the anterior portion of the body. Anal fin long relative to the dorsal fin; 132-139 anal rays; 144-153 dorsal rays; and 14-17 pectoral rays. Gill rakers 7. Palantine teeth uniserial.

Blotched Cusk-eel Ophidion grayi

Crested Cusk-eel Ophidion josephi

Striped Cusk-eel Ophidion marginatum

Ophidion grayi
Blotched Cusk-eel – Ophidion grayi
Ophidion marginatum
Striped Cusk-eel – Ophidion marginatum

Blotched Cusk-eel Ophidion grayi. Elongate, compressed; head compressed; head profile convex from snout to dorsal fin origin; snout moderately blunt, slightly overhanging, with a small, blunt spine projecting down towards its tip; gill rakers – 2 rudiments above, 4 rakers below; operculum with a strong, hidden spine; dorsal and anal fins continuous with tail; dorsal fin 133-144; anal fin 98-105; pelvic fins (each with 2 rays of unequal length) inserted under eye; scales smooth, elongate, not overlapping, at right angles rather than regular series, none on head; lateral line along most of body. Light tan; 2 irregular rows of dark brown spots and blotches, upper row from top of body to lateral line, lower row from lateral line down, some of upper row spots coalesced into horizontal blotches; top of head and dorsal fin with scattered dark brown spots; margin of dorsal fin with black blotches; anal fin clear, with black margin (https://biogeodb.stri.si.edu/caribbean/en/thefishes/species/3104/on).

Crested Cusk-eel Ophidion josephi. Elongate, compressed; head compressed; head profile nearly straight from tip of snout to behind eye; mature male with crest on nape; snout with a small, blunt spine projecting down towards tip of snout; gill rakers: 2 rudiments above, 4 rakers below; operculum with a strong, hidden spine; dorsal and anal fins continuous with tail; dorsal fin 138-146; anal fin 114-121; pelvic fins (each with 2 rays of unequal length) inserted under eye; scales smooth, elongate, not overlapping, at right angles rather than regular series, none on head; lateral line along most of body. Tan; 3 rows of dark spots along body, upper row usually fused into an irregular stripe, middle row partly or completely fused in a stripe on or below lateral line; dorsal fin with a long black blotch at front, a black margin behind that blotch; anal fin with black margin (https://biogeodb.stri.si.edu/caribbean/en/thefishes/species/3106).

Striped Cusk-eel Ophidion marginatum. Elongate, compressed; head compressed; head profile nearly straight from tip of snout to behind eye; snout moderately pointed, slightly overhangs jaws, with a spine projecting down towards tip; male with prominent crest on nape; 4-5 lower gill rakers; operculum with a strong, hidden spine; dorsal and anal fins continuous with tail; dorsal fin 147-158; anal fin 118-124; pelvic fins (each with 2 rays of unequal length) inserted under eye; scales smooth, elongate, not overlapping, at right angles rather than regular series, none on head; lateral line along most of body. Grey-green above, golden on side, white below; body with 2-3 dark stripes along its entire length, 1 along lateral line; side of head with brown spots; dorsal fin pale green, with black margin; anal fin with black margin (https://biogeodb.stri.si.edu/caribbean/en/thefishes/species/3108).

References

FAO. 1999. Species catalogue. Volume 18. Ophidiiform fishes of the world (Order Ophidiiformes). An annotated and illustrated catalogue of pearlfishes, cusk-eels, brotulas and other ophidiiform fishes known to date. FAO Fisheries Synopsis. No. 125, Vol. 18. 178p., 136 figs. Rome, Italy.

Lea, R. N. and C. R. Robins. 2003. Four new species of the genus Ophidion (Pisces: Ophidiidae) from the western Atlantic Ocean. University of Kansas Museum of Natural History. Scientific Papers No. 31: 1-9.

Robertson, D.R. and J. Van Tassell. 2019. Shorefishes of the Greater Caribbean: online information system. Version 2.0 Smithsonian Tropical Research Institute, Balboa, Panamá (https://biogeodb.stri.si.edu/caribbean/en/pages).

Robins, C. R. and J. E. Böhlke. 1959. Studies on fishes of the family Ophidiidae. IV. Two new dwarf cusk-eels (genus Ophidion) from the tropical western Atlantic. Notulae Naturae. No. 325: 1-9.

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