Sharpnose Puffer in Cozumel

A small puffer with a pointed snout and bright blue lines radiating from the eye, hovering in one spot with its tail cocked to the side. Slow, approachable and one of the most photographed small fish on the reef.

Quick ID

Scientific name	Canthigaster rostrata
Group	Camouflaged & Odd-Shaped Fish
Typical size	Up to 12 cm
Depth range	2–40 m
When to see it	Year-round
Active	Day
Conservation status	Least Concern
Notes	Toxic if eaten — never handled

How To Identify It

Tan to olive above, white below, with electric blue lines around the eye and across the snout, and a dark bar at the base of the tail. The body is laterally compressed and the snout distinctly pointed.

Where You Will See It In Cozumel

Over rubble, sponge and reef structure at almost any depth a diver goes. Frequently near the base of coral heads and around sea rods.

Reliable sites: Paradise Reef, Chankanaab, Yucab, Tormentos, Paso del Cedral.

Behaviour

Picks at sponges, algae, molluscs and small crustaceans. It hovers with fine sculling of the pectoral fins and moves slowly, relying on toxicity rather than speed.

Like other puffers it can inflate with water when threatened. Provoking that response stresses the fish badly — it is not something to make a fish do for a photograph.

Commonly Confused With

• Bandtail puffer — Larger, rounder, with dark bands on the tail and no blue eye lines.
• Whitespotted filefish — Has a raised first dorsal spine and a different body outline.

Diving Etiquette And Safety

Toxic if eaten — never handled. Keep fins off the reef and hands to yourself — nothing here needs to be touched or provoked to be seen well.

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

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