Cocos Island fish

Reef fish

Reef fish

25 species · grouped as on REEF survey sheets

A 2016 checklist confirmed 514 marine fish species at Cocos Island (Fourriére et al. 2016). Most reef fish here are shared with the other islands of the Eastern Tropical Pacific. Coral is limited: about 90 percent of the reefs died after the 1982–83 El Niño (UNESCO), so much of the diving is over boulders, rock and sand.

The table lists the reef fish named most often in dive reports from Cocos, grouped as on REEF fish survey sheets, then sorted by common name. Each row says where at Cocos it has been reported, with the source.

Table 1 — Reef fish reported at Cocos Island, grouped as on the REEF Tropical Eastern Pacific survey sheets (Other last), then sorted by common name. Each fish’s family is shown under its scientific name. Photos credited to Megan Applegate were taken at Cocos Island in August 2024, except those the credits mark as taken at Malpelo; fish marked “No photo yet” link to photos on Wikimedia Commons.

Photo	Common name	Species	At Cocos	Profile
Butterflyfish Chaetodontidae · 1 species
	Barberfish	Johnrandallia nigrirostrisChaetodontidae	Works the hammerhead cleaning stations at Manuelita (Blue Water Dive Travel).	FishBase · Smithsonian
Eel Muraenidae · 5 species
No photo yet	Fine-spotted moray	Gymnothorax doviiMuraenidae	One of the morays commonly seen on the reefs (SEE Turtles 2024).	FishBase · Smithsonian · Photos (Commons)
No photo yet	Giant moray	Gymnothorax javanicusMuraenidae	On the reefs; individuals about 2 m long were seen in 2024 (SEE Turtles 2024).	FishBase · Photos (Commons)
No photo yet	Starry moray	Echidna nebulosaMuraenidae	One of the morays seen on the reefs (SEE Turtles 2024).	FishBase · Photos (Commons)
No photo yet	Yellow-edged moray	Gymnothorax flavimarginatusMuraenidae	One of the morays commonly seen on the reefs (SEE Turtles 2024; SEE Turtles 2024).	FishBase · Photos (Commons)
	Zebra moray	Gymnomuraena zebraMuraenidae	On the reefs (SEE Turtles 2024).	FishBase · Smithsonian
Hawkfish Cirrhitidae · 2 species
	Coral hawkfish	Cirrhitichthys oxycephalusCirrhitidae	Photographed perched under plate coral at Cocos in August 2024 (photo on this page).	FishBase · Smithsonian
	Longnose hawkfish	Oxycirrhites typusCirrhitidae	Lives in black coral and sea fans; photographed in a sea fan at Cocos in August 2024 (photo on this page).	FishBase · Smithsonian
Jack Carangidae · 3 species
	Bigeye trevally	Caranx sexfasciatusCarangidae	Schools of thousands, sometimes stacked about 18 m from top to bottom (SEE Turtles 2024); over 200 at Submerged Rock and thousands around divers at Dirty Rock (Blue Water Dive Travel).	FishBase · Smithsonian
No photo yet	Black jack	Caranx lugubrisCarangidae	Seen on a night dive at Manuelita Shallows (Blue Water Dive Travel).	FishBase · Photos (Commons)
	Bluefin trevally	Caranx melampygusCarangidae	Reported at Dirty Rock (Blue Water Dive Travel).	FishBase · Smithsonian
Puffer Diodontidae · 1 species
	Porcupinefish	Diodon hystrixDiodontidae	Photographed on the reef at Cocos in August 2024 (photo on this page).	FishBase · Smithsonian
Seabass Serranidae · 3 species
	Cocos serrano	Serranus ticoSerranidae	Tiny and common on the reefs (SEE Turtles 2024).	FishBase · Smithsonian
	Leather bass	Dermatolepis dermatolepisSerranidae	On the reefs, often near morays (SEE Turtles 2024).	FishBase · Smithsonian
	Pacific creolefish	Cephalopholis colonusSerranidae	Very abundant, in large schools at every dive site (SEE Turtles 2024).	FishBase · Smithsonian
Snapper Lutjanidae · 3 species
	Blue-and-gold snapper	Lutjanus viridisLutjanidae	In mixed schools with Mexican goatfish (SEE Turtles 2024); schools at Dirty Rock (Blue Water Dive Travel).	FishBase · Smithsonian
	Jordan's snapper	Lutjanus jordaniLutjanidae	Photographed at Cocos (Oceanlight).	FishBase · Smithsonian
	Yellow snapper	Lutjanus argentiventrisLutjanidae	In the swim-through at Submerged Rock (DAN).	FishBase · Smithsonian
Squirrelfish Holocentridae · 1 species
	Bigscale soldierfish	Myripristis berndtiHolocentridae	Soldierfish shelter in the swim-through at Submerged Rock and in deeper water at Punta María (DAN).	FishBase · Smithsonian
Wrasse Labridae · 1 species
	Mexican hogfish	Bodianus diplotaeniaLabridae	Juveniles clean hammerheads at the cleaning stations (SEE Turtles 2024).	FishBase · Smithsonian
Other Antennariidae, Mullidae, Ogcocephalidae, Pomacanthidae, Zanclidae · 5 species
No photo yet	Cocos batfish	Ogcocephalus porrectusOgcocephalidae	Rarely seen, usually deeper than about 37 m (SEE Turtles 2024); DAN reports it on the sand at Silverado (DAN). Long thought to live only at Cocos, but in 2026 a specimen was reported from the Pacific coast of mainland Costa Rica (Angulo et al. 2026).	FishBase · Photos (Commons)
No photo yet	Commerson's frogfish	Antennarius commersonAntennariidae	Well camouflaged on the reefs; dive guides often point them out (SEE Turtles 2024). DAN mentions orange frogfish at Manuelita (DAN).	FishBase · Photos (Commons)
No photo yet	King angelfish	Holacanthus passerPomacanthidae	A cleaner at the hammerhead cleaning stations (SEE Turtles 2024).	FishBase · Smithsonian · Photos (Commons)
	Mexican goatfish	Mulloidichthys dentatusMullidae	In mixed schools with blue-and-gold snappers (SEE Turtles 2024; Oceanlight).	FishBase · Smithsonian
	Moorish idol	Zanclus cornutusZanclidae	In the Coral Garden (SEE Turtles 2024).	FishBase · Smithsonian

Pelagics

Open water

Seen in the blue, not on the reef

The seamounts around Cocos hold the largest predator biomass recorded in the tropical Pacific, according to a 2009 National Geographic expedition reported by DAN.

Credits

Fish photo credits

Photos and their sources

Photos credited to Megan Applegate are her own, taken on her dives at Cocos Island in August 2024 or, where marked, at Malpelo, and are © Megan Applegate, all rights reserved.

Other photos are credited in the table, with a link to the page each came from.