Guam fish

Reef fish

Reef fish

79 species · grouped by family

More than 880 reef fish species in nearly 100 families live on Guam’s reefs, against about 600 in Hawai‘i; about half belong to ten families, led by gobies, wrasses and damselfish (Guampedia). Two are found only in the Mariana Islands: the Guam damsel and the yellow-crowned butterflyfish (Guampedia).

The table lists reef fish that appear in the Mariana Islands galleries of GuamReefLife, the Guam reef-life photo identification site (GuamReefLife), or that Megan Applegate photographed at Guam in December 2022, grouped by family and sorted by common name. The “Look for” notes come from each fish’s English Wikipedia and FishBase pages, linked in the row, and from dive reports (Tim Rock, DivePhotoGuide). “Park survey” gives the number of 38 belt transects in the War in the Pacific National Historical Park, on Guam’s west coast, where the fish was recorded, for the 25 most widespread species (Brown & Capone 2014). CHamoru names come from Kerr’s 1990 list of Chamorro fish names and the University of Guam fish poster (Kerr 1990; University of Guam).

Table 1 — Reef fish of Guam, grouped by family (Other last), then sorted by common name. Each fish’s family is shown under its scientific name, and its CHamoru name, where one was found, under its common name. Photos were taken at Guam in December 2022 or, where marked, at other Pacific sites (see the credits); fish marked “No photo yet” link to photos on Wikimedia Commons.

Photo	Common name	Species	Look for	Profile
Angelfish and Moorish idol Pomacanthidae, Zanclidae · 5 species
No photo yet	Emperor angelfish	Pomacanthus imperatorPomacanthidae	Adults have horizontal blue and yellow stripes, a dark blue mask over the eyes and a yellow tail; juveniles are dark blue with white and blue rings.	FishBase · Wikipedia · Photos (Commons)
No photo yet	Lemonpeel angelfish	Centropyge flavissimaPomacanthidae	Bright yellow, with a blue ring around the eye and blue fin edges. Park survey: on 13 of 38 transects	FishBase · Wikipedia · Photos (Commons)
No photo yet	Mango angelfish	Centropyge shepardiPomacanthidae	Red to apricot, usually with dark vertical bars. Found only in the Marianas, Guam and Ogasawara; first described from the west side of Cocos Island, Guam, and named after John W. Shepard of the University of Guam.	FishBase · Wikipedia · Photos (Commons)
	Moorish idolCHamoru: ababang rayao	Zanclus cornutusZanclidae	Disc-shaped, with a tube snout and a long, whip-like dorsal filament.	FishBase · Wikipedia
	Royal angelfish	Pygoplites diacanthusPomacanthidae	Orange-yellow with blue-edged white bars. Seen at Fingers Reef.	FishBase · Wikipedia
Butterflyfish Chaetodontidae · 8 species
No photo yet	ForcepsfishCHamoru: ababang	Forcipiger flavissimusChaetodontidae	Yellow, with a long forceps-like snout. The longnose butterflyfish (F. longirostris) also lives on Guam and looks very similar.	FishBase · Wikipedia · Photos (Commons)
No photo yet	Mailed butterflyfishCHamoru: ababang	Chaetodon reticulatusChaetodontidae	Blackish with pale scale centres, a yellow-edged eye band with a white bar behind it, and a yellow band on the tail edge.	FishBase · Wikipedia · Photos (Commons)
No photo yet	Ornate butterflyfishCHamoru: ababang	Chaetodon ornatissimusChaetodontidae	White with orange oblique bands and two yellow-edged black bars on the head, one through the eye and one on the snout.	FishBase · Wikipedia · Photos (Commons)
No photo yet	Raccoon butterflyfishCHamoru: ababang	Chaetodon lunulaChaetodontidae	A black-and-white “raccoon mask” over the eyes, oblique reddish stripes and a black spot on the tail base.	FishBase · Wikipedia · Photos (Commons)
No photo yet	Speckled butterflyfishCHamoru: ababang	Chaetodon citrinellusChaetodontidae	Pale yellow with many small dark spots, a black eye bar and a black edge on the anal fin; usually in pairs on shallow reef flats.	FishBase · Wikipedia · Photos (Commons)
No photo yet	Threadfin butterflyfishCHamoru: ababang	Chaetodon aurigaChaetodontidae	White with chevron lines, a black eye band, yellow rear fins and a black spot with a trailing filament on the dorsal fin.	FishBase · Wikipedia · Photos (Commons)
No photo yet	Threeband pennantfishCHamoru: ababang gupalao	Heniochus chrysostomusChaetodontidae	White with three broad oblique brown bands and long front dorsal rays forming a pennant; up to 18 cm.	FishBase · Wikipedia · Photos (Commons)
No photo yet	Yellow-crowned butterflyfish Marianas endemicCHamoru: ababang	Chaetodon flavocoronatusChaetodontidae	Split diagonally: silvery white in front and below, jet black on the upper rear, with yellow bands through the eye and over the crown. A deep-water fish, rarely seen by recreational divers.	FishBase · Wikipedia · Photos (Commons)
Damselfish and anemonefish Pomacentridae · 7 species
	Clark’s anemonefish	Amphiprion clarkiiPomacentridae	Lives in sea anemones; dark with white bands and a yellow tail.	FishBase · Wikipedia
No photo yet	Dusky anemonefish	Amphiprion melanopusPomacentridae	Dark red to orange, with one white head band behind the eye and black pelvic and anal fins.	FishBase · Wikipedia · Photos (Commons)
No photo yet	Guam damsel Marianas endemic	Pomachromis guamensisPomacentridae	A small damselfish, about 4.5 cm, at 3–33 m. Found only in the Mariana Islands.	FishBase · Wikipedia · Photos (Commons)
No photo yet	Humbug dascyllus	Dascyllus aruanusPomacentridae	White with three black vertical bars and a white spot between the eyes.	FishBase · Wikipedia · Photos (Commons)
No photo yet	Indo-Pacific sergeant	Abudefduf vaigiensisPomacentridae	Whitish with a yellow upper back and black bars. Sergeant majors are reported at Fingers Reef and Fish Eye; three Abudefduf species live on Guam.	FishBase · Wikipedia · Photos (Commons)
No photo yet	Princess damsel	Pomacentrus vaiuliPomacentridae	A small damselfish with several colour forms. The fish found on the most transects in the War in the Pacific park survey. Park survey: on 36 of 38 transects	FishBase · Wikipedia · Photos (Commons)
	Reticulate dascyllus	Dascyllus reticulatusPomacentridae	Grey, with two dark vertical stripes and a blue-green tail.	FishBase · Wikipedia
Eels Congridae, Muraenidae · 4 species
	Giant morayCHamoru: hakmang	Gymnothorax javanicusMuraenidae	The heaviest moray, over 3 m: brown with black specks that become leopard-like spots behind the head.	FishBase · Wikipedia
No photo yet	Snowflake morayCHamoru: hakmang	Echidna nebulosaMuraenidae	A blunt white snout, a black-and-yellow speckled pattern and yellow tubular nostrils.	FishBase · Wikipedia · Photos (Commons)
	Spotted garden eel	Heteroconger hassiCongridae	White with many small black spots and three larger ones. Lives in colonies on current-swept sand at 15–45 m, each eel a third out of its burrow, facing the current to catch plankton. Photographed at Guam in December 2022 (photo on this page).	FishBase · Wikipedia
No photo yet	Yellow-edged morayCHamoru: hakmang	Gymnothorax flavimarginatusMuraenidae	Dull yellow with dark brown mottling.	FishBase · Wikipedia · Photos (Commons)
Groupers Serranidae · 3 species
No photo yet	Flagtail grouperCHamoru: amadeo	Cephalopholis urodetaSerranidae	Reddish, with a rounded tail marked by two pale diagonal stripes. The third most widespread fish in the War in the Pacific park survey. Park survey: on 30 of 38 transects	FishBase · Wikipedia · Photos (Commons)
No photo yet	Peacock hindCHamoru: gådao maluslus	Cephalopholis argusSerranidae	Dark brown covered in small dark-edged blue spots; large fish may show pale bars at the rear.	FishBase · Wikipedia · Photos (Commons)
No photo yet	Yellow-edged lyretailCHamoru: gådao mattingan	Variola loutiSerranidae	A lyre-shaped tail with a yellow edge.	FishBase · Wikipedia · Photos (Commons)
Hawkfish Cirrhitidae · 3 species
	Arc-eye hawkfish	Paracirrhites arcatusCirrhitidae	Pale pinkish brown with a horseshoe-shaped mark behind the eye; perches on coral heads.	FishBase · Wikipedia
	Blackside hawkfish	Paracirrhites forsteriCirrhitidae	A broad dark band along the rear half of the body and red speckles on the head.	FishBase · Wikipedia
	Dwarf hawkfish	Cirrhitichthys falcoCirrhitidae	Pinkish red and white with bars or mottling, and tasselled dorsal spines. Park survey: on 15 of 38 transects	FishBase · Wikipedia
Jacks Carangidae · 2 species
	Bluefin trevally	Caranx melampygusCarangidae	Up to 117 cm, with a more pointed snout than most jacks.	FishBase · Wikipedia
No photo yet	Giant trevallyCHamoru: tarakito	Caranx ignobilisCarangidae	The largest Caranx. Curious, well-fed giant trevally gather at Gab Gab II in Apra Harbor.	FishBase · Wikipedia · Photos (Commons)
Goatfish Mullidae · 3 species
No photo yet	Dash-and-dot goatfishCHamoru: sakmoneten pento	Parupeneus barberinusMullidae	A dark stripe from the lip through the eye (the dash) and a black spot on the tail base (the dot).	FishBase · Wikipedia · Photos (Commons)
No photo yet	Manybar goatfish	Parupeneus multifasciatusMullidae	Chin barbels and dark bars on a reddish body; colour very variable.	FishBase · Wikipedia · Photos (Commons)
No photo yet	Yellowstripe goatfish	Mulloidichthys flavolineatusMullidae	Grey-white with a yellow stripe and yellowish fins; often in schools. Its numbers spill over from the Piti preserve into Asan Bay.	FishBase · Wikipedia · Photos (Commons)
Parrotfish Labridae (Scarinae) · 3 species
No photo yet	Bumphead parrotfishCHamoru: atuhong	Bolbometopon muricatumLabridae (Scarinae)	The largest parrotfish: a vertical head profile with a bulbous forehead and exposed tooth plates. Now very rare on Guam (see below). Vulnerable on the IUCN Red List.	FishBase · Wikipedia · Photos (Commons)
No photo yet	Ember parrotfish	Scarus rubroviolaceusLabridae (Scarinae)	Males bright greenish blue; females duller brown.	FishBase · Wikipedia · Photos (Commons)
No photo yet	Pacific bullethead parrotfishCHamoru: palaksi	Chlorurus spilurusLabridae (Scarinae)	Initial phase dark reddish with a pale tail base; terminal males greenish with purple-blue lines around the mouth and an orange-and-white cheek patch. Listed as C. sordidus in the park survey. Park survey: on 25 of 38 transects	FishBase · Wikipedia · Photos (Commons)
Puffers, boxfish and porcupinefish Diodontidae, Ostraciidae, Tetraodontidae · 7 species
	Blackspotted pufferCHamoru: buteten malulasa	Arothron nigropunctatusTetraodontidae	Grey, brown, bluish or yellow with scattered black spots, and a dog-like face. Photographed at Guam in December 2022 (photo on this page).	FishBase · Wikipedia
	Guineafowl pufferCHamoru: butete	Arothron meleagrisTetraodontidae	Dark with many small white spots, or all yellow.	FishBase · Wikipedia
	Spot-fin porcupinefishCHamoru: tituka’	Diodon hystrixDiodontidae	Large round eyes, spines all over and a beige body with black spots; usually about 40 cm.	FishBase · Wikipedia
	Spotted boxfishCHamoru: toriyu	Ostracion meleagrisOstraciidae	A boxy body; males blackish above with blue sides, females dark with white spots.	FishBase · Wikipedia
No photo yet	Spotted sharpnoseCHamoru: butete	Canthigaster solandriTetraodontidae	A small puffer, up to 11.5 cm, with a sharp nose. Park survey: on 14 of 38 transects	FishBase · Wikipedia · Photos (Commons)
	White-spotted pufferCHamoru: buteten malulasa	Arothron hispidusTetraodontidae	Grey to yellowish with white spots, white and dark rings around the eye and the pectoral fin, and a dark patch around the pectoral fin; up to 50 cm, at 3–35 m. Photographed at Guam in December 2022 (photo on this page).	FishBase · Wikipedia
	Yellow boxfishCHamoru: toriyu	Ostracion cubicusOstraciidae	A boxy body covered in spots. Juveniles are bright yellow with black spots; the yellow fades with age. Up to 45 cm. Photographed at Guam in December 2022 (photo on this page).	FishBase · Wikipedia
Rabbitfish Siganidae · 1 species
No photo yet	Forktail rabbitfishCHamoru: biting kalau	Siganus argenteusSiganidae	Slender, with a deeply forked tail and silvery cheeks and belly. First described from Guam; schools of young fish arriving on Guam’s reef flats support a brief local fishery.	FishBase · Wikipedia · Photos (Commons)
Scorpionfish and lionfish Scorpaenidae · 3 species
No photo yet	False stonefish	Scorpaenopsis diabolusScorpaenidae	A humped back and mottled camouflage; the inner pectoral fins flash orange, black and white. Venomous spines.	FishBase · Wikipedia · Photos (Commons)
No photo yet	Red lionfishCHamoru: nufo’ pabu	Pterois volitansScorpaenidae	Native here; it is invasive only in the Atlantic. Venomous spines.	FishBase · Wikipedia · Photos (Commons)
No photo yet	Spotfin lionfishCHamoru: nufo’ pabu	Pterois antennataScorpaenidae	A long tentacle above each eye. All five Marianas lionfish live on Guam; lionfish are reported at Hap’s Reef, Barracuda Rock and Coral Gardens. Venomous spines.	FishBase · Wikipedia · Photos (Commons)
Snappers Lutjanidae · 3 species
No photo yet	Black-and-white snapper	Macolor nigerLutjanidae	Adults grey to black with black fins; juveniles boldly striped in black and white.	FishBase · Wikipedia · Photos (Commons)
	Bluestripe snapperCHamoru: funai	Lutjanus kasmiraLutjanidae	Yellow with four blue stripes.	FishBase · Wikipedia
No photo yet	Two-spot red snapperCHamoru: tagåfi	Lutjanus boharLutjanidae	Reddish with darker fins and a groove from the nostril to the eye; juveniles have two silvery-white spots on the back. Large adults may carry ciguatera.	FishBase · Wikipedia · Photos (Commons)
Squirrelfish and soldierfish Holocentridae · 2 species
No photo yet	Sabre squirrelfishCHamoru: sisi’ok	Sargocentron spiniferumHolocentridae	The largest squirrelfish: bright red, with a deep-red patch behind the eye and a long cheek spine.	FishBase · Wikipedia · Photos (Commons)
No photo yet	Shoulderbar soldierfishCHamoru: saksak	Myripristis kunteeHolocentridae	Red above, silvery pink below, with a reddish-brown bar behind the head.	FishBase · Wikipedia · Photos (Commons)
Surgeonfish and unicornfish Acanthuridae · 8 species
No photo yet	Bluespine unicornfishCHamoru: tataga’ (adults), guasa’ (young)	Naso unicornisAcanthuridae	Blue-grey, with a short horn on the forehead (missing in small fish) and two blue spines on each side of the tail base.	FishBase · Wikipedia · Photos (Commons)
No photo yet	Brown surgeonfish	Acanthurus nigrofuscusAcanthuridae	Brown to purplish, with small orange spots on the head and black spots at the bases of the dorsal and anal fins. Park survey: on 28 of 38 transects	FishBase · Wikipedia · Photos (Commons)
No photo yet	Convict tangCHamoru: kichu	Acanthurus triostegusAcanthuridae	Yellowish white with six black bars, the first through the eye. Seen at Gun Beach and in Tumon Bay.	FishBase · Wikipedia · Photos (Commons)
No photo yet	Lined surgeonfish	Acanthurus lineatusAcanthuridae	Black-edged blue and yellow stripes. The tail spines are venomous.	FishBase · Wikipedia · Photos (Commons)
No photo yet	Orangespine unicornfishCHamoru: hangon	Naso lituratusAcanthuridae	Orange lips, a black face mask and bright orange spines on the tail base; no horn. Spawns year-round near Guam. Park survey: on 25 of 38 transects	FishBase · Wikipedia · Photos (Commons)
No photo yet	Striated surgeonfishCHamoru: oda’	Ctenochaetus striatusAcanthuridae	Greenish brown with thin wavy blue lines and orange spots on the head. First described from Guam, in 1825. Park survey: on 16 of 38 transects	FishBase · Wikipedia · Photos (Commons)
No photo yet	Whitespotted surgeonfish	Acanthurus guttatusAcanthuridae	Grey covered in white spots, with a white band behind the eye and another behind the yellow pelvic fins. Seen in Tumon Bay.	FishBase · Wikipedia · Photos (Commons)
	Yellow tang	Zebrasoma flavescensAcanthuridae	Bright yellow all over, with a white spine on the tail base; up to about 20 cm. Its range includes the Mariana Islands. Photographed at Guam in December 2022 (photo on this page).	FishBase · Wikipedia
Triggerfish and filefish Balistidae, Monacanthidae · 5 species
	Harlequin filefish	Oxymonacanthus longirostrisMonacanthidae	Blue-green covered in bright orange spots, with a long snout and a black spot on the tail; feeds on coral. Vulnerable on the IUCN Red List. Photographed at Guam in December 2022 (photo on this page).	FishBase · Wikipedia
No photo yet	Orange-lined triggerfishCHamoru: pulonnon	Balistapus undulatusBalistidae	Dark green-brown covered in curving orange lines. Park survey: on 11 of 38 transects	FishBase · Wikipedia · Photos (Commons)
No photo yet	Picasso triggerfishCHamoru: pulonnon	Rhinecanthus aculeatusBalistidae	A bold, painted “Picasso” pattern; lives from the shallows to 50 m.	FishBase · Wikipedia · Photos (Commons)
	Pinktail triggerfishCHamoru: pulonnon	Melichthys viduaBalistidae	Very dark green, looking black, with translucent white second dorsal and anal fins and a pink tail.	FishBase · Wikipedia
No photo yet	Titan triggerfishCHamoru: sasadu’	Balistoides viridescensBalistidae	The largest triggerfish in its range, with a deep groove in front of the eye. Females guarding nests have attacked divers: keep clear.	FishBase · Wikipedia · Photos (Commons)
Wrasse Labridae · 8 species
No photo yet	Bird wrasseCHamoru: palaksi	Gomphosus variusLabridae	A long, beak-like snout and a jerky, flapping swim with its pectoral fins.	FishBase · Wikipedia · Photos (Commons)
No photo yet	Bluestreak cleaner wrasse	Labroides dimidiatusLabridae	A black stripe from the eye widening to the tail, white or bluish elsewhere; runs cleaning stations. Park survey: on 14 of 38 transects	FishBase · Wikipedia · Photos (Commons)
	Humphead wrasseCHamoru: tangison	Cheilinus undulatusLabridae	Very large, with thick lips, two black lines behind the eye and a hump on the forehead of large adults. Endangered on the IUCN Red List; now very rare on Guam (see below).	FishBase · Wikipedia
No photo yet	Red-lined wrasseCHamoru: palaksi	Halichoeres biocellatusLabridae	Males silver-grey with thin red stripes; females and juveniles have two white-rimmed dark spots on the dorsal fin. Park survey: on 26 of 38 transects	FishBase · Wikipedia · Photos (Commons)
No photo yet	Ringtail Maori wrasse	Oxycheilinus unifasciatusLabridae	A white band around the tail base and red lines radiating back from the eye. Park survey: on 20 of 38 transects	FishBase · Wikipedia · Photos (Commons)
No photo yet	Slingjaw wrasse	Epibulus insidiatorLabridae	A hugely extendable jaw. Males grey-brown with an orange back and a pale head with a black eye stripe; females bright yellow or dark brown. Seen at Fingers Reef.	FishBase · Wikipedia · Photos (Commons)
No photo yet	Sunset wrasseCHamoru: palaksi	Thalassoma lutescensLabridae	Initial phase yellow with faint red vertical lines; terminal males blue to blue-green behind a pink-and-green head. Park survey: on 14 of 38 transects	FishBase · Wikipedia · Photos (Commons)
No photo yet	Yellowtail corisCHamoru: palaksi	Coris gaimardLabridae	Juveniles red with large black-edged white spots; adults with a bright yellow tail and blue specks toward the rear.	FishBase · Wikipedia · Photos (Commons)
Other Aulostomidae, Blenniidae, Gobiidae, Microdesmidae · 4 species
No photo yet	Blueband goby	Valenciennea strigataGobiidae	Pale grey with a yellow head and a curved blue bar below the eye. Park survey: on 16 of 38 transects	FishBase · Wikipedia · Photos (Commons)
	Fire dartfish	Nemateleotris magnificaMicrodesmidae	A yellow head, a white body shading to a red-orange tail, and a very long front dorsal fin that it flicks; up to 9 cm. Hovers over its sand burrow at 6–70 m and darts in when threatened. Photographed at Guam in December 2022 (photo on this page).	FishBase · Wikipedia
No photo yet	Forktail blenny	Meiacanthus atrodorsalisBlenniidae	A blue-edged black line running diagonally from the eye and a yellow back. Venomous bite. Park survey: on 17 of 38 transects	FishBase · Wikipedia · Photos (Commons)
No photo yet	TrumpetfishCHamoru: ba’yak	Aulostomus chinensisAulostomidae	A long tube snout with a chin barbel; brown, or the yellow form. Yellow trumpetfish are seen at Fingers Reef.	FishBase · Wikipedia · Photos (Commons)

Pressure

Where did the big fish go?

Spearfishing, and the fish that came back in the preserves

The humphead wrasse (tangison) and the bumphead parrotfish (atuhong) have been described as “on the verge of being extinct in local Guam waters”; 85% of the recorded catch of the two since 1985 was taken by spearfishers on scuba (Marianas Variety). The National Park Service says spearfishing on scuba has probably contributed to their dramatic decline (US National Park Service).

Guam’s parrotfish fell by about 30% between video surveys in 2012 and 2021. Of the sites where they increased, 63% were inside marine preserves, and 70% of the sites where they fell were outside. Public Law 35-78, passed in March 2020, bans spearfishing while on scuba (University of Guam). In the Piti Bomb Holes preserve fish numbers more than doubled, and a 2007 study found them spilling over into Asan Bay (Wikipedia).

Credits

Fish photo credits

Photos and where they were taken

Photos credited to Megan Applegate are © Megan Applegate, all rights reserved. The white-spotted and blackspotted puffers, yellow boxfish, spotted garden eel, yellow tang, harlequin filefish and fire dartfish were taken at Guam in December 2022; her other photos show the same species in Palau, the Solomon Islands, Malpelo or Cocos Island, as each credit says. The others are reference photos with open licences, credited below.