Other common names include Pacific oarfish, king of herrings, ribbonfish, and streamer fish.

[4] Its physical characteristics and undulating mode of swimming have led to speculation that it might be the source of many "sea serpent" sightings.

These larvae exhibit an elongated body with rays extending from the occipital crest and a long pelvic fin, identical to that of the adult fish.

[12] Unlike the adult form of the species, the skin of the larvae is almost entirely transparent with intermittent spots of dark coloration along the organism's dorsum and head.

[12] This dark pigmentation is presumably an adaptation developed for counter-shading when the adult fish is vertical in the water column.

[13] Adults have a pale silver ribbonlike body shape that is laterally compressed and extremely elongated with a dorsal fin along its entire length from between its eyes to the tip of its tail, ranging in color from faint pinkish to a bright red.

[4] At the head of the fish, the first 10–12 of these dorsal fin rays are lengthened, forming the distinctive red crest associated with the species.

The organs of the giant oarfish are concentrated toward the head end of the body, possibly enabling it to survive losing large portions of its tail.

[15] The lateral line begins above and behind the eye then, descending to the lower third of the body, extends to the caudal tip.

[20] In 2010, scientists filmed a giant oarfish in the Gulf of Mexico swimming in the mesopelagic layer, the first footage of a reliably identified R. glesne in its natural setting.

The footage was caught during a survey, using an ROV in the vicinity of Thunder Horse PDQ, and shows the fish swimming in a columnar orientation, tail downward.

[3] Another report of the stomach contents of two adult R. glesne consisted of 43 heads and 7 individuals of Mediterranean krill.

This amputation can either be just involving the caudal fin and a small number of vertebrae, or it may be the entire posterior part of the body.

[3] Eggs have been found in the waters of New Zealand and near the West Mariana ridge in the western North Pacific.

[2][26] When cooked, the taste of an oarfish is described as “like paper.”[27] R. glesne was offered to a dog who regularly consumes fish, and was refused.

Six people agreed to try fried oarfish and said that the taste was suitable, but the flesh was extremely flaccid, and overall objectionable.

[28] Due to their size, elongated bodies, and undulating swimming pattern, giant oarfish are presumed to be responsible for some sea serpent sightings.

[29] Formerly considered rare, the species is now suspected to be relatively common, although sightings of healthy specimens in their natural habitat are unusual.