Is the Nassau grouper endangered?

Yes — it is listed as Critically Endangered, largely because it was fished at its predictable spawning aggregations.

How do you tell a Nassau grouper from a black grouper?

The Nassau has five clean vertical bars and a black saddle on the tail base. The black grouper has a chain-link rectangular pattern and no saddle.

No. They are protected and often approachable, which makes restraint the diver's responsibility rather than the fish's.

Nassau Grouper in Cozumel

Q: Where do you see them in Cozumel?

Under coral heads and overhangs at Paso del Cedral, Tormentos and Yucab.

Nassau Grouper (*Epinephelus striatus*) in Cozumel: how to identify it, where it is reliably seen, and what it is commonly confused with.

A heavy-bodied grouper with five dark bars running vertically down a pale body, a black saddle on the tail base, and a dark band through the eye. The whole pattern can wash out or intensify within seconds.

Quick ID

Scientific name	Epinephelus striatus
Group	Predators & Big Fish
Typical size	40–90 cm
Depth range	5–30 m
When to see it	Year-round
Active	Daytime
Conservation status	Critically Endangered
Notes	Protected species

Where You Will See It In Cozumel

Individuals sit under coral heads and overhangs at Paso del Cedral, Tormentos and Yucab, usually alone and usually still.

Reliable sites: Paso del Cedral, Tormentos, Yucab.

Behaviour

Sedentary and often approachable, which is precisely why the species collapsed across the Caribbean — it aggregates predictably to spawn and was fished out at those aggregations. Cozumel individuals are frequently tolerant of divers at a respectful distance.

Commonly Confused With

Black grouper — Black grouper carry a rectangular chain-link pattern rather than clean vertical bars, and no black saddle on the tail base.
Tiger grouper — Tiger grouper have oblique, slanted bars and a more pointed head.

Diving Etiquette And Safety

Critically Endangered and protected. Do not feed, corner or crowd. The black saddle on the tail base is the identification feature worth photographing for citizen-science reporting.

Part of the Cozumel marine life guide · see Cozumel dive sites · plan your Cozumel dive trip

Photo: NOAA OAR/National Undersea Research Program, Public domain, via Wikimedia Commons.