Fairy Basslet in Cozumel

Purple at the front, yellow at the back, with a hard line between the two. Tiny, and usually upside down under a ledge — it orients its belly to the nearest surface, so on a cave roof it swims inverted.

Quick ID

Scientific name	Gramma loreto
Group	Colourful Reef Fish
Typical size	Up to 8 cm
Depth range	3–60 m
When to see it	Year-round
Active	Day
Conservation status	Least Concern

How To Identify It

The front half is deep violet, the rear half golden yellow, with an abrupt transition and a dark stripe through the eye. Nothing else on a Caribbean reef looks like it.

Where You Will See It In Cozumel

Under ledges, in swim-throughs and along the shaded faces of the walls. Palancar Caves and the overhangs at Santa Rosa are reliable; look up into the roof of any cut.

Reliable sites: Santa Rosa Wall, Palancar Gardens, Columbia Shallows.

Behaviour

Stays close to cover and orients to the nearest surface rather than to gravity, which is why they appear upside down under overhangs. They feed on zooplankton picked from the water just outside their shelter and dart back at any movement.

Commonly Confused With

• Royal gramma — The same fish. Fairy basslet and royal gramma are two names for Gramma loreto.
• Blackcap basslet — Purple with a black cap and no yellow rear.

Diving Etiquette And Safety

Keep fins off the reef and hands to yourself. Nothing here needs to be touched, moved or provoked to be seen well.

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

Photo © Stephen Hoerler, courtesy of the Cozumel Coral Reef Restoration Program, used with permission.