Dusky grouper (Epinephelus marginatus) — spearfishing in Morocco

Legal size: —; not in the table
Maximum size: Up to 150 cm and 60 kg
Maximum age: Over 50 years
Depth: 5 to 50 m, occasionally 300

Mediterranean Atlantic Difficulty · Accessible IUCN · Vulnerable

This species does not appear in the Moroccan marketable size table. That does not mean it is unrestricted: it means we have found no text covering it. Our gaps.

What the legal size does not tell you

First maturity: Females around 45 to 50 cm, at about five years, in the Balearic study
Sex change: Female first, then male between roughly 60 and 90 cm, at ten to fourteen years: the big fish are the only males

The legal size comes from the 1988 order, written for commercial fishing. The maturity sizes come from scientific studies, each carried out in one particular area: they give an order of magnitude, not a rule.

01 Telling it apart

A massive, thick-set fish with a huge head, a wide mouth with a projecting lower jaw, and a rounded tail. The colour is dark brown mottled with irregular pale yellowish blotches that fade and darken with mood. The dorsal is long with a low spiny front half; the pectoral and tail fins have pale edges.

It sits at the mouth of a hole or on a ledge, or hangs in open water just off its rock, and it turns to face a diver rather than leaving.

Juveniles are more strongly patterned and live in shallower rock pools and gullies.

02 Habitat

Holes, arches, ledges and boulder fields on rocky coasts, from a few metres down. A grouper takes a territory with one or more shelters and keeps it for years; large individuals hold the best holes and are known to divers by name.

It hunts from its shelter, ambushing octopus, crustaceans and fish, and it patrols the rock around it in daylight.

Juveniles grow up in shallow rock and move deeper as they age.

03 Where to find it in Morocco

Rocky coasts on both seaboards. Historically abundant everywhere; now scarce and small wherever it is fished, and abundant only inside effective reserves.

There is no Moroccan population study. Everything known about its growth and sex change comes from the Mediterranean, mostly the Balearics and the French coast.

04 Spawning

Summer, from June to August, in aggregations of one large male and several females on the rock where they live.

Female first: a grouper is born female and turns male only around ten to fourteen years old, at 60 to 90 cm. The large fish in a territory are therefore its only males, and removing them leaves the females with no partner for years.

05 Behaviour

Curious and unafraid. A grouper often comes out of its hole to look at a diver, hangs a metre or two away, and watches. It is the least wary large fish on the coast, and it is the reason the species collapsed wherever it was fished.

Growth is slow and site fidelity is total: a hole emptied of its grouper is not refilled for years, and a coast emptied of its large males has no breeding for a generation.

How you approach it

No approach is given here: see the caution.

What people get wrong

01 That a grouper that comes to you is a sign of a healthy population. It comes to everyone; that is why there are so few.
02 That a big grouper is an old female full of eggs. The big fish are the males, the only ones, and the females around them depend on them.
03 That because Morocco lists no size for it, it is free. The 1988 table is a commercial list, not a statement that everything absent from it may be taken.

Do not confuse it with

The species this one is taken for, and what tells them apart.

Goldblotch grouper, Epinephelus costae — slimmer and paler, grey-brown with a golden blotch behind the pectoral in juveniles, and it swims in midwater more than it sits in holes.
Comb grouper, Mycteroperca rubra — more elongated, reddish brown with fine pale spots and a lunate tail, in open water over deep rock.
Brown meagre, Sciaena umbra — also dark and also under overhangs, but with a tiny mouth, a high curved back and yellow lower fins.

Dusky grouper