Fish Identification: Grouper

In a nutshell: big and ugly---that's what today's fish is. Grouper can be a familiar dive sighting, depending on where you dive. Even the sea bass is technically part of the grouper family, but we'll be treating them separately.

Physical description

Grouper have oblong, stout bodies and a large mouth, probably not unlike some of your relatives. Typical lengths are over a meter, and can get to over 2 meters for the various giant varieties.

Their large mouths resemble a frown, contributing to the grouper's unfriendly appearance. If you catch one with its mouth open, you will get a glimpse of its powerful gill muscles.

Dusky Grouper
The pectoral fins have a fanlike appearance when in use. Combined with the fanned caudal fin, this is suggestive of the grouper's slow, but strong swimming abilities.

There are over 60 species of grouper, so coloring varies wildly. Most often, though, grouper are a darkly colored brown, olive, or black with lighter splotches across their body.

Oh yeah, did I say that they're big and ugly?

Geography and habitat

Potato Grouper
Grouper are found all over the world, with specific species local to different oceans. Their habitats can be a little more varied than most coral fish we cover here, including wanderings out to open water, due to their large size.

Grouper tend to be loner fish, and sometimes plant themselves beneath rocks and coral waiting for unsuspecting prey. At that time, they will use their strong gills to suck water, and the fish, into their mouths. Impressive.


Grouper have become a popular sport fishing fish. Due to their size, I imagine they put up a good fight that fishermen find enjoyable.

Grouper are also eaten, although the environmental defense fund recommends caution. As with most larger fish, grouper have high mercury levels that could be dangerous to humans.

Further reading

Florida Museum of Natural History

Grouper photo by loveā™”janine
Dusky grouper photo by Phillipe Guillaume
Potato grouper photo by Tim Sheerman-Chase