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Northern gemfish (Rexea prometheoides) — Gempylidae

Northern gemfish

Rexea prometheoides
Family: Gempylidae

The Northern gemfish (Rexea prometheoides) is a saltwater fish of the family Gempylidae that grows up to 40 cm.

Length
40 cm
Water
Saltwater
Depth
135.0–540.0 m
Diet
Carnivore
Behaviour
Small groups
Body shape
Elongated (eel-like)
Substrate
Mixed bottom
Danger
Harmless
Edibility
Rarely eaten

Description

The royal escolar is a deep-water fish of the snake mackerel family (Gempylidae) from the Indo-West Pacific. The species grows to about 40 cm and has an elongate, silvery body with large eyes and a large mouth with sharp teeth. It lives benthopelagically on the continental slope at considerable depth and makes nightly migrations to shallower water. As a fast predator it feeds on fishes, crustaceans and cephalopods. Like related snake mackerels it has oily flesh with indigestible wax esters, which can cause intestinal upset if eaten. Owing to its deep habits the species is harmless to humans.

Frequently asked questions

How do you recognise the Northern gemfish?

The Northern gemfish has an elongate, eel-like body, is mainly silver-grey and shows a plain pattern.

Where does the Northern gemfish live?

The Northern gemfish lives in the sea (marine waters) and is mostly found around mixed bottom.

How big does the Northern gemfish get?

The Northern gemfish grows to a maximum of about 40 cm.

Is the Northern gemfish dangerous to humans?

No, the Northern gemfish is harmless to humans.

Is the Northern gemfish edible?

The Northern gemfish is rarely eaten.

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All data

Identification

Dutch name
Koninklijke slangmakreel sourced
English name
Northern gemfish verified
Scientific name
Rexea prometheoides
Family
Gempylidae
Other names
Prometheus gemfish; Royal escolar; Royal gemfish verified

Appearance

Size class
Medium verified
Max length (cm)
40.0 verified
Body shape
Elongated (eel-like) sourced
Dominant colour
Silver / grey inferred
Pattern
Plain inferred
Tail shape
Forked inferred
Mouth position
Terminal inferred
Lips
Thin inferred
Barbels
No sourced
Dorsal fins
Two separate inferred
Dorsal spines
Yes sourced

Habitat & distribution

Water type
Saltwater sourced
Substrate
Mixed bottom sourced
Min depth (m)
135.0 verified
Max depth (m)
540.0 verified
Origin
Native sourced

Behaviour & biology

Diet
Carnivore sourced
Social behaviour
Small groups inferred
Territorial
No inferred
Reproduction
Separate sexes sourced
Sexual dimorphism
No inferred

For anglers

Edibility
Rarely eaten sourced
Fishing method
Bodemvissen met natuurlijk aas (worm, garnaal of vis) op of vlak boven de bodem. inferred
Regulations source
FishBase ↗ inferred

Safety

Danger to humans
Harmless sourced

Status & sources

Sources
FishBase via GBIF (DwC-A), CC-BY-NC 4.0

Same genus Rexea

More from the family Gempylidae

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