Hawaiian Reef Fish

Hawaiian Reef Fish

Hawaiian Name: I‘a

[Illustration: Reef fish]


Family: Pomacanthidae

Angelfishes are territorial fish that use their brush-like teeth to eat algae and sponges.  The rear-pointing spine on the gill cover of angelfishes is the main trait distinguishing them from butterflyfishes. 

Angelfishes also have what is known as a haremic social system in which a single male defends two to five female fish.  A favorite sight for many snorkelers and divers, angelfish are also commonly sought after for use in aquariums.

Of the 80 known species of angelfish worldwide, five are native to the main Hawaiian Islands.  Four of these five native Hawaiian angelfish species are endemic to the Hawaiian Islands (found around the Hawaiian Islands and nowhere else).  Two other angelfish species also might be seen in Hawaiian waters: the Japanese pygmy angelfish (Centropyge interruptus), which is native to the Hawaiian Islands but found only in the Northwestern Hawaiian Islands; and the extremely rare emperor angelfish (Pomacanthus imperator), with just a few sightings ever (and thus not currently considered a native breeding population).

The aquarium trade accounts for the capture of more than 400,000 Hawaiian reef fish each year, and has severely depleted the populations of many species. 

Recent breakthroughs in raising these desirable reef fish in captivity have used a newly developed zooplankton food source for the small fish larvae allowing researchers to raise several species for the first time, including masked angelfish (Genicanthus personatus), Fisher’s angelfish (Centropyge fisheri), and flame angelfish (Centropyge loriculus). 

These new scientific techniques for raising Hawaiian reef fish were developed by researchers at the Oceanic Institute, the Waikīkī Aquarium, and the Hawai‘i Institute of Marine Biology, and have the potential to ease the pressure on precious and dwindling native fish populations. 

These new technologies also may be used in developing an industry in the Hawaiian Islands raising ornamental reef fish for export.

[Illustration: Angelfish]



[Photograph: Bandit Angelfish]

Bandit Angelfish (Desmoholacanthus arcuatus)

Length: Up to 7 inches (18 cm).


A broad black band runs horizontally for the length of the bandit angelfish’s gray and white body (gray above the band and white to pale gray below).  The black band also covers the eye region, giving the appearance of a robber’s (bandit’s) mask.  The tail and anal fin also are banded with black.  The color pattern of the bandit angelfish is unique among the angelfish.

Feeding on sponges, the bandit angelfish sometimes swims out in the open and often alone, and is a relatively curious fish around humans.  An endemic Hawaiian species, the bandit angelfish is seen most frequently at depths of about 80 to 100 feet (24 to 30 m) around most of the Hawaiian Islands, and is particularly common on Kaua‘i where it may be seen by snorkelers.  The bandit angelfish feeds on sponges. 

The bandit angelfish is sometimes scientifically classified in the genus Apolemichthys, or Desmoholacanthus, rather than Holacanthus.



[Photograph: Fisher’s Angelfish]

Fisher’s Angelfish (Centropyge fisheri)

Also Called: Dusky Angelfish

Length: Up to 3 inches (8 cm).


The fisher’s angelfish is orange-brown in color with a bluish-brown sheen and a yellowish tail.  An iridescent blue color rims the anal, dorsal and pelvic fins.  The tail and pectoral fins are yellowish.

The fisher’s angelfish is often seen in groups of five to ten fish around finger coral at depths of 30 to 80 feet (9 to 24 m) and deeper, feeding on filamentous algae.

Endemic to the Hawaiian Islands, the species is named after Walter K. Fisher, a zoologist from California who was involved in research in the Hawaiian Islands in the early 1900s.



[Photograph: Flame Angelfish]

Flame Angelfish (Centropyge loriculus)


Length: Up to 4 inches (10 cm).

Bright (flame) red in color, the flame angelfish has dark black bars running vertically down its body.  The flame angelfish also has blue lining its rear fins, and this blue lining is more prominent in males. 

The flame angelfish is the most visually striking of the angelfish (along with the bandit angelfish).  A slightly brighter red color between the black bars distinguishes the Hawaiian flame angelfish from other flame angelfish.

  Relatively rare in Hawaiian waters, flame angelfish are sometimes seen in shallow waters, but are seen more commonly below 60 feet (18 m) deep among finger coral.  Flame angelfish eat filamentous algae, and are often seen repeatedly within a relatively small area.  They are highly prized as aquarium fish.



[Photograph: Masked Angelfish]

Masked Angelfish (Genicanthus personatus)

Length: Up to 10 inches (25 cm).


Female masked angelfish are white, with a black patch on the forehead and over the eye region and above the eyes.  There is also a black bar on the tail.  Males are white to bluish-gray, rimmed with orange on the tail and around the eyes, with a black bar on the tail.

Masked angelfish are endemic to the Hawaiian Islands, but only rarely seen around the main Hawaiian Islands, instead almost exclusively residing in the Northwestern Hawaiian Islands where they feed on zooplankton. 

Around the main Hawaiian Islands the masked angelfish is usually seen at depths from 200 to 300 feet (60 to 90 m) but may be may be seen at depths of around 60 feet (18 m) or deeper near the Northwestern Hawaiian Islands.

A highly prized aquarium fish, the masked angelfish is sometimes sold for more than $1,000.



[Photograph: Potter’s Angelfish]

Potter’s Angelfish (Centropyge potteri)

Length: Up to 5 inches (13 cm).


 The potter’s angelfish is the most commonly seen angelfish in Hawaiian waters, and one of the most commonly seen Hawaiian reef fish. 

The front of the fish (head and upper body) is rusty orange in color, darkening to a blackish-blue color below (bluer in males), with many irregular, dark grayish to blue vertical lines running the length of the body.  The bluish colors are more pronounced in males. 

The potter’s angelfish is usually seen at depths of 15 feet (4.6 m) or more down to about 100 feet (30 m).  Often seen darting about the coral, the potter’s angelfish feeds on filamentous algae. 

This endemic fish gained its scientific species name (potteri) after former Waikīkī Aquarium director Frederick A Potter who ran the aquarium from 1903 to 1940.




Family: Chaetodontidae

Characterized by its tiny, brush-like or comb-like teeth, the butterflyfish’s scientific name (Chaetodontidae) derives from “chaeto,” meaning hair, and “dentis,” meaning tooth. 

With narrow snouts well suited for probing crevices of coral reefs, different butterflyfish species utilize different food sources, including plankton, invertebrates, coral, and algae.

There are about 115 butterfly species worldwide, and at least 24 of these species are native to the Hawaiian Islands.  Butterflyfish are generally less than 8 inches (20 cm) long, and have disk shaped bodies that are often yellow and brightly colored, usually with a dark bar over the eye area. 

There is sometimes a false eyespot near the tail to confuse predators.  The butterflyfish’s bright color pattern during the day may differ from its more subdued appearance at night, when the fish generally rests within the many hiding places of the coral reef.

Butterflyfish multiply by releasing eggs that hatch into larvae.  The parents give no care to the young.  As adults, the fish often travel in pairs that may be long-term mates.

In ancient Hawai‘i, some varieties of the butterflyfish were considered sacred, and are mentioned in ancient chants.  The Hawaiian word kīkākapu (kīkā means strong, kapu means forbidden and/or sacred) refers to fish in the genera Cheilodactylus as well as Chaetodon, and specific varieties are referred to with the qualifying terms ko‘a and lua. 

Lauwiliwili is the term for Chaetodon milaris, while lau hau refers to the brightly colored Chaetodon umimaculatus and Chaetodon quadrimaculatus.  To refer to specific varieties, the term lauwiliwili may be qualified with other terms, such as kīkākapu, kapuhili, nuku ‘i‘wi, wiliwili, or maha uli.  The term kapuhili refers to Chaetodon trifasciatus.

Not included here are the extremely rare double-saddle butterflyfish (Chaetodon ulietensis), and the Chevron butterflyfish (Chaetodon trifascialis), which is seen only in the Northwestern Hawaiian Islands.



[Photograph: Bluehead butterflyfish]     

Blacklip Butterflyfish (Chaetodon kleinii)

Also called: Bluehead Butterflyfish; Klein’s Butterflyfish


Length: Up to 5 inches (13 cm).

The bluehead butterflyfish is a speckled, golden, yellow-brown in color and feeds on soft corals and zooplankton.  The fish has dark (black) colored lips and dark vertical bar running through the eye region, which is brown to black below the eye and blue above the eye. 

Each scale also has a bluish spot.  The bluehead butterflyfish is a relatively common reef fish around the Hawaiian Islands, usually seen at depths below 40 feet (12 m).



[Photograph: Bluestripe butterflyfish]

Bluestripe Butterflyfish (Chaetodon fremblii)

Hawaiian name: Kīkākapu


Length: Up to 6 inches (15 cm).

The bluestripe butterflyfish is common among the shallow nearshore reefs and also seen in deeper waters.  Bright blue bands run diagonally to obliquely along the fish’s yellow body, which becomes a darker yellow when the fish is alarmed. 

The fish also has a black spot above and behind the eye (on the forehead, or nape), and a black spot at the rear (posterior) of the fish, extending onto the base of the tail and the dorsal fin.  Found only in Hawaiian waters and often seen alone, the bluestripe butterflyfish feeds on algae, tubeworm tentacles, and other invertebrates.

Known as a relic species, the bluestripe butterflyfish has no obvious close relatives (which means that it has likely been in Hawaiian waters a very long time).  The bluestripe butterflyfish may be seen in shallow water reef areas as well as deeper waters up to about 600 feet (183 m).



[Photograph: Forceps butterflyfish]       

Forceps Butterflyfish (Forcipiger flavissimus)

Hawaiian Name: Lauwiliwili Nukunuku ‘Oi‘oi

Also called: Forcepfish; Common Longnose Butterflyfish


Length: Up to 7 inches (18 cm).

A mostly yellow fish with a long, slender snout, the longnose butterflyfish is commonly seen probing the crevices of coral reefs, and is sometimes seen swimming upside down near the roofs of caves. 

Also notable for its large, bristling dorsal spines, the longnose butterflyfish has a black upper head region and a black spot on its anal fin.  The lower half of the fish’s head is white.

The longnose butterflyfish is probably the most widely found butterflyfish, inhabiting areas from the East Africa to the Red Sea, to Mexico and the Americas.  The fish inhabits depths ranging from the shallows down to about 100 feet (30 m), using their long snout to feed on small crustaceans, fish eggs, tubeworms, and the tubefeet of sea urchins.

The common longnose butterflyfish (forcepfish) has a smaller mouth opening than the rare longnose butterflyfish, but is otherwise very similar.  The Hawaiian name of the common longnose butterflyfish, lauwiliwili nukunuku ‘oi‘oi, means “sharp beaked wiliwili leaf,” referring to the native wiliwili tree (Erythrina sandwicensis, Hawaiian coral tree). (See Wiliwili in Native Plants and Ferns of the Hawaiian Islands, Chapter 8.)



[Photograph: Fourspot butterflyfish]     

Fourspot Butterflyfish (Chaetodon quadrimaculatus)

Hawaiian Name: Lauhau


Length: Up to 6 inches (15 cm).

The upper portion of the fourspot butterflyfish’s body is dark brown with two large white spots (on each side of the fish).  The lower portion of the fish’s body is orange-yellow in color.  The scales of this orange-yellow region each have a small brown spot. 

The head and tail of the fourspot fish is yellow, and a darker stripe (ocular bar) runs over the eye region.  This ocular bar is orangish below the eye but darker above, and narrowly edged with blue and black.  The dorsal and anal fins also have a line of blue.

Fourspot butterflyfish often rest beneath ledges and feed mostly on coral polyps.  They may be seen in relatively shallow waters, and down to about 50 feet (15 m).



[Photograph: Lined butterflyfish]           

Lined Butterflyfish (Chaetodon lineolatus)

Hawaiian Name: Kīkākapu


Length: Up to 12 inches (30 cm).

Usually seen in pairs on shallow reefs as well as deeper areas, the lined butterflyfish is not a particularly common Hawaiian reef fish, but is Hawai‘i’s largest butterflyfish.  They may be seen in shallow reef areas but also have been spotted at depths of more than 500 feet (152 m).

More than a dozen dark lines run vertically on the sides of the lined butterflyfish’s white body.  A dark vertical bar runs over eye region, and above the eye within this dark bar is a white spot.  The dorsal, anal, and tail fins are yellow. 

The general appearance of the lined butterflyfish is somewhat similar to the threadfin butterflyfish, but the lined butterflyfish has a wide, black marking that arcs below the dorsal fin and in front of its yellowish tail region. 

The lined butterflyfish also has only one set of vertical dark lines, unlike the two diagonal sets of dark lines on the threadfin butterflyfish.

The lined butterflyfish feeds on algae and small invertebrates, such as anemones and coral polyps.



[Photograph: Milletseed butterflyfish]    

Milletseed Butterflyfish (Chaetodon miliaris)

Hawaiian Name: Lauwiliwili


Length: Up to 6½ inches (16.5 cm).

Also known as the lemon butterflyfish, the milletseed butterflyfish is a friendly, bright yellow fish.  Vertical rows of dark spots (resembling millet seeds) line the sides of the fish.  There is a dark bar over the eye region and a dark spot at the base of the tail (caudal peduncle).  The dark spots, said to resemble millet seeds, are arranged in vertical or diagonal rows.

Milletseed butterflyfish are seen in shallow waters as well as at depths of more than 800 feet (244 m).  Their diet is primarily zooplankton but also includes the eggs of the Sergeant Major fish.  Milletseed butterflyfish also occasionally clean other fish. 



[Photograph: Ornate butterflyfish]         

Ornate Butterflyfish (Chaetodon ornatissimus)

Hawaiian Name: Kīkākapu


Length: Up to 8 inches (20 cm).

An attractive and relatively common reef fish, the ornate butterflyfish has six orange bands that run diagonally on the side of the ornate butterflyfish’s white body, which is rimmed with black. 

Six vertical black bars, with yellow between, cover the face and head.  One of the black bars continues along the length of the dorsal area and onto the fins and tail.

The ornate butterflyfish is found in shallow waters as well as at depths to about 90 feet (27 m).  Adults are usually seen in pairs, though they may be seen singly among coral branches feeding on live coral polyps.

[Photograph: Ornate Butterflyfish]


[Photograph: Oval butterflyfish]

Oval Butterflyfish (Chaetodon lunulatus)

Hawaiian Name: Kapuhili

Also called: Redfin Butterflyfish


Length: Up to 5.5 inches (14 cm).

A black eye bar is prominent on the oval butterflyfish’s orange-yellow head.  Also known as the redfin butterflyfish, the oval butterflyfish’s body is orangish-yellow with nearly horizontal purple-gray lines, and a reddish anal fin. 

The oval butterflyfish feeds on live coral polyps, and inhabits reef areas, particularly in calm bay and lagoon areas.  Not particularly common, they are usually seen in pairs in shallow waters or at depths to about 60 feet (18 m). 



[Photograph: Pebbled butterflyfish]       

Pebbled Butterflyfish (Chaetodon multicinctus)

Hawaiian Name: Kīkākapu

Also called: Multiband Butterflyfish


Length: Up to 4½ inches (11 cm).

Fairly common in Hawaiian waters but found nowhere else, the pebbled butterflyfish has a cream to tan-colored body with many small brownish-olive spots, and four or five vertical beige-brown bars that sometimes are barely visible.   A black bar covers the eye region, and there is black at the outer edge and the base of the tail.

Usually seen pairs or larger groupings, the pebbled butterflyfish feeds on coral polyps.  The fish may be seen in shallow reef areas as well as at depths to about 90 feet (27 m).



[Photograph: Pennant butterflyfish]       

Pennant Butterflyfish (Heniochus diphreutes)

Also called: Bannerfish; Pennantfish


Length: Up to 8 inches (20 cm).

Two prominent, diagonal black bars on a white body, along with a white pennant (rarely a double pennant), make the pennant butterflyfish easily recognizable.  The white banner is actually the fourth dorsal spine and membrane, and this filament grows longer as the fish matures.  The pennant butterflyfish’s tail, dorsal fin, and pectoral fin are yellow.

Pennant butterflyfish are sometimes seen in shallow waters but usually at depths below 40 feet (12 m), often near steep dropoffs, feeding on zooplankton.  They are often seen in schools.

Pennant butterflyfish are also known to clean other fish.  Aquarium lovers appreciate the adaptability of the pennant butterflyfish, and sometimes refer to it as the “poor man’s Moorish idol,” another fish with similar ‘cleaning’ behavior (See Moorish idol section.) 

The Moorish idol is somewhat similar in appearance, but has a much longer snout than the pennant butterflyfish.



[Photograph: Pyramid butterflyfish]       

Pyramid Butterflyfish (Hemitaurichthys polylepis)

Also called: Brownface Butterflyfish


Length: Up to 7 inches (18 cm).

A large white triangle (pyramid) in the center of the body of the pyramid butterflyfish is surrounded by yellow.  The head is dark brown while the dorsal and anal fins are yellow. 

The pyramid butterflyfish feeds on zooplankton and is often seen in large schools.  The fish may be seen in shallow waters (e.g., Hōnaunau on Hawai‘i Island’s Kona coast), but is more commonly seen in deeper waters from about 20 to 100 feet (6 to 30 m), preferring steep dropoff zones.



[Photograph: Raccoon butterflyfish]      

Raccoon Butterflyfish (Chaetodon lunula)

Hawaiian Name: Kīkākapu


Length: Up to 8 inches (20 cm).

The raccoon butterflyfish has an orange-yellow body (dusky on the top half), with three reddish, diagonal stripes.  The black bar over the eye region of this fish bears a resemblance to the raccoon, a small mammal native to North America. 

Behind the black eye bar is a white crescent (lunula means “crescent”), and then a black bar extending onto the body and upward.  At the base of the tail there is a black spot, extending upward into a narrowing black band.  Juveniles have a relatively large false eyespot and are brighter than adults.

Large resident schools of the fish may inhabit particular locations year after year, resting relatively motionless during the day.  The raccoon butterflyfish may be seen in the shallows or down to about 50 feet (15 m), feeding on various small invertebrates as well as coral polyps, fish eggs, and algae. 

The fish’s body turns brownish at night.  The raccoon butterflyfish is not shy, and is commonly seen by snorkelers and divers.



[Photograph: Longnose butterflyfish]    

Longnose Butterflyfish (Forcipiger longirostris)

Hawaiian Name: Lau-wiliwili-nukunuku-‘oi‘oi

Also called Big Longnose Butterflyfish; Rare Longnose Butterflyfish


Length: Up to 8 inches (20 cm).

With a long snout but a small mouth opening, this fish is well adapted to feeding among the coral reefs.  Its body is yellow with rows of blackish spots on the chest area. 

The longnose butterflyfish has a longer snout than the forceps butterflyfish (Forcipiger flavissimus), but otherwise is almost identical in appearance.  A black color phase sometimes occurs, particularly in longnose butterflyfish populations along the island of Hawai‘i’s Kona Coast.

Longnose butterflyfish may be seen in relatively shallow waters or to depths of about 100 feet (30 m).  They feed primarily on crustaceans but also eat fish eggs, tube feet of urchins, and tube worms.



[Photograph: Reticulated butterflyfish]  

Reticulated Butterflyfish (Chaetodon reticulatus)


Length: Up to 7 inches (18 cm).

This beautiful fish is quite uncommon throughout the Hawaiian Islands, though is often seen (usually in pairs) along the island of Hawai‘i’s Kona Coast, and sometimes in O‘ahu’s Hanauma Bay.  The head and eye of the fish are covered by a black bar that is lined at the front with yellow. 

Behind the black eye bar, the fish is gray and black, with a pattern of creamy white to yellow markings (a spot on each scale).  There is also a red area on the anal fin.  The outer edge of the tail and anal fin are lined with yellow. 

Feeding on coral polyps as well as algae, the reticulated butterflyfish may be seen in relatively shallow waters and to depths of about 90 feet (27 m).



[Photograph: Teardrop butterflyfish]     

Teardrop Butterflyfish (Chaetodon unimaculatus)

Hawaiian Name: Lauhau; Kīkākapu.


Length: Up to 7½ inches (19 cm).

The teardrop butterflyfish’s most distinctive feature is the large, black, upside-down teardrop-shaped mark on the upper center portion of its body (unimaculatus means “one spot”).  The white body is yellow toward the top, and a wide, black bar covers the eye region.

Not a particularly common fish, the teardrop butterflyfish is usually seen in pairs at depths between 20 and 100 feet (6 to 30 m), feeding on coral polyps, worms, crustaceans, and algae.  The fish’s blunt mouth is well adapted for chewing hard pieces of coral off the reef.



[Photograph: Thompson’s Butterflyfish]

Thompson’s Butterflyfish (Hemitaurichthys thompsoni)

Also called: Businessman Butterflyfish


Length: Up to 6 inches (15 cm).

The Thompson’s butterflyfish is recognized by its short, upturned snout and gray to black-brown color, which is quite unlike the showy, bright colors of all other butterflyfish species.  Thompson’s butterflyfish are quite friendly but relatively rare, often congregating in schools with pyramid butterflyfish. 

The species’ scientific name, thompsoni, honors John W. Thompson who worked for the Bishop Museum from 1901 to 1928, and was known for his colorful casts of Hawaiian fish.  Thompson’s butterflyfish are usually seen at depths of 33 feet (10 m) or more, feeding on zooplankton.



[Photograph: Threadfin butterflyfish]

Threadfin Butterflyfish (Chaetodon auriga)

Hawaiian name: Kīkākapu


Length: Up to 8 inches (20 cm).

A relatively common reef fish, the threadfin butterflyfish is yellow-orange or goldish toward the back, and white at the front with a broad, black bar over the eye region.  On the body of the fish are two groupings of dark, diagonal lines that are at right angles to each other.

Above the black spot at the top rear of the fish (on the dorsal fin) is a thread-like filament that is actually an extension of one of the dorsal spines.  Threadfin butterflyfish are territorial in pairs, driving away other threadfin butterflyfish but tolerating different species (including other species of butterflyfish).

Threadfin butterflyfish are often seen in pairs in shallow waters at depths to about 50 feet (15 m).  They feed primarily on worms, algae, and coral polyps.



[Photograph: Tinker’s butterflyfish]       

Tinker’s Butterflyfish (Chaetodon tinkeri)


Length: Up to 7 inches (18 cm).

The body of the tinker’s butterflyfish is black on the top toward the back but white with black spots toward the front.  A bar over the eye region is golden yellow, as is the tail.  There is also a gold marking on the snout and at the base of the pectoral fins. 

Not a shy fish, the tinker’s butterflyfish is easily caught by collectors who export the fish for sale in the aquarium trade.  This had made the tinker’s butterflyfish quite rare at depths above 100 feet (30 m), where it feeds on planktonic invertebrates.

The tinker’s butterflyfish is named after marine biologist Spencer Wilkie Tinker, who directed the O‘ahu’s Waikīkī Aquarium for more than three decades.




Family: Scaridae

Parrotfishes (Scaridae) are among the largest and most beautifully colored fish inhabiting Hawaiian coral reefs.  Of the seven known species of parrotfish native to Hawaiian waters, three are endemic to the Hawaiian Islands (found nowhere else).

Parrotfishes use their pectoral fins for propulsion.  The tail is also used for propulsion, especially when a burst of speed is required.  Parrotfishes may secrete a mucous cocoon around themselves at night as protection from predators, such as eels.  The mucous cocoon may also protect the parrotfish from crustacean parasites.


‘A‘ohe e loa‘a, he uhu pakelo.

He will not be caught, for he is a parrotfish, slippery with slime.

Said of a person too wily and wise to be caught.

                                                                        (Pukui: 131-17)


Parrotfishes are herbivorous, and feed by scraping algae off the surface of coral reefs.  They bite into the live coral using their fused teeth (which resemble a parrot’s beak), and ingest the coral along with the algae. 

The digestive system of the parrotfish includes bony, grinding plates in the back of the throat that help the fish break down the bits of coral into fine sand.  With no true stomach, but with an exceptionally long intestine, they grind the coral into sand, and then expel the sand. 

A single adult parrotfish may produce up to 1 ton (.9 mton) of sand per year, making it a major contributor to the sand supply around the Hawaiian Islands.

The parrotfish’s bright colors (in most species) and beak-like teeth are responsible for the fish’s common name, parrotfish.  The most colorful parrotfish are the terminal phase males (also called dominant males, or supermales), which are females that have changed sex to become males.  Juvenile parrotfish appear very different than adults.  These color and sex changes are similar to what occurs in wrasse species, the group from which parrotfish are believed to have evolved.

Initial phase adult parrotfish may be male or female, and are generally modestly colored (drab gray or reddish-brown) and often gather in schools.  Terminal phase parrotfish are females that have become males, and these are the largest and most colorful of the parrotfish. 

They are often bright green or blue-green.  Terminal phase fish stake out specific territories and mate with particular females, which may be part of a harem.

The colors of the parrotfish are so beautiful that the fish is sometimes compared to a beautiful person, as in the Hawaiian saying: “Momomi wale ku‘u ‘ono i ka uhu mā‘alo i ku‘u maka, which means,” “My craving makes my mouth water for the parrotfish passing before my eyes.” (Pukui and Elbert, 1986.)

Hawaiian names for the growth stages of the uhu (parrotfish) include ‘ōhua for very young fish, and pānuhu for medium sized fish, while uhu refers to mature parrotfish. 

Some parrotfish species have specific Hawaiian names for different phases.  For example, an initial phase spectacled parrotfish is known as uhu ‘ahu ‘ula, which is a reference to the colorful royal feather cloaks known as ‘ahu ‘ula.  A terminal phase spectacled parrotfish is referred to as uhu uliuli, referring to the fish’s dark, blue-green colors.



[Photographs: Bullethead parrotfish (initial phase; terminal phase)]

Bullethead Parrotfish (Chlorurus sordidus)

Hawaiian Name: Uhu


Length: Up to 15 inches (38 cm).

The body of the male bullethead parrotfish is pastel blue-green with an orange-yellow blush on the side (toward the back), and small, vertical, pink lines on the fish’s scales.  The female is reddish-black/brown with a double row of white spots toward the back, and with a white tail that has a black spot on it.

The bullethead parrotfish get its common name from the symmetrical shape of its head.  A relatively common reef fish, it may be seen in shallow as well as deeper waters, feeding on coral and algae.  At night the fish may be seen sleeping in a cocoon of mucous (see Parrotfishes above).



[Photograph: Spectacled parrotfish]

Spectacled Parrotfish (Chlorurus perspicillatus)

Hawaiian Name: Uhu ‘Ahu‘ula (initial phase); Uhu Uliuli (terminal phase).


Length: Up to 24 inches (61 cm).

Spectacled parrotfish are grayish-brown to reddish-brown in the initial phase, with red fins and a broad white area at the base of the tail.  Terminal phase males are blue-green with a lavender colored head.  The upper snout has a purple bar lined with blue. 

The terminal male spectacled parrotfish also has orange-pink spots at the front, orange-pink edged scales at the rear, and yellow at the base of the pectoral fins.  Spectacled parrotfish feed on coral and algae.

The Hawaiian name for the initial phase, uhu ‘ahu‘ula, is a reference to the royal feather capes (‘ahu ‘ula), which perhaps were compared to the reddish colors on the fish.  The term for the terminal phase fish, uhu uliuli, means “dark-colored uhu,” referring to the striking blue-green colors of the fish.



Surgeonfishes (Tangs)

Family: Acanthuridae

Surgeonfishes are among the most abundant Hawaiian reef fish.  Also called tangs, surgeonfishes are mostly herbivorous, feeding on algae.  The surgeonfish is named for the sharp scalpel-like spines at the base of its tail fin, with one or two of the spines on each side of the fish.  These spines are sometimes brightly colored. 

The scientific family name of surgeonfish, Acanthuridae, derives from the Greek “akanthos,” which means “thorn.”  Sometimes brightly colored, the sharp spines normally lie flat against the body, but in an instant may point outward to ward off predators. 

Some surgeonfish species have venom in their scalpels as well as in their fin spines.  With a rapid swipe of its tail the surgeonfish is able to slice into predators (and careless humans).

Most surgeonfish prefer relatively shallow water, where they use their specially adapted mouths to scrape algae off coral or rock.  Some surgeonfish also eat seaweed. 

Large schools of surgeonfish are often seen grazing over shallow reef areas and will readily swarm in large schools near groups of humans intent on feeding them.  Hanauma Bay is a common location to observe this fish-human behavior.

At least 24 species of surgeonfish may be seen in Hawaiian waters, though one (Acanthurus lineatus) is extremely rare, with only two of the fish having been spotted. 

The Acanthuridae family also includes unicornfish (Naso species), referred to by ancient Hawaiians as kala, which also means “rough,” a reference to the skin of the fish. 

The abrasive skin of kala was sometimes used for sanding by ancient Hawaiians. (See Kukui in Seed Lei, Chapter 3), and was used for the drum head of the pūniu, or coconut knee drum. 

The pūniu, which is unique to the Hawaiian Islands, was made by stretching the skin of the kala (favored for its tiny scales) over the shell of the coconut (Cocos nucifera). (See Niu in Polynesian-Introduced Plants, Chapter 9.)

Fish in the Naso genus have two spines on each side, and they are fixed in place, while fish in the genera Zebrasoma, Ctenochaetus, and Acanthurus have only one spine per side, and they may fold down almost flush into a groove on the side of the fish.

Surgeonfishes are similar to parrotfishes and wrasses in that they primarily use their pectoral fins for propulsion.  The closely related Moorish Idol, the lone member of the Zanclidae family, also uses its pectoral fins for propulsion though it lacks the spines of the surgeonfish.



[Photograph: Achilles tang]

Achilles Tang (Acanthurus achilles)

Hawaiian name: Pāku‘iku‘i


Length: Up to 10 inches (25 cm).

The Achilles tang is mostly black with some white around the margins, and a distinguishing bright orange-red, elliptical (teardrop-shaped) mark near the base of the tail around the scalpel region (in adult fish).  The tail fin is mostly orange-red, with a thin black line and then a wider white area at the back of the tail.

Named after the legendary Greek warrior Achilles who was known for his strength and bravery, the Achilles tang is a very territorial fish. 

A common Achilles tang behavior is an aggressive burst of speed and a quick turn to display the sharp scalpel-like spine.  This is done to intimidate other fish.  An agitated Achilles tang may also flare its fins and show a reddish tint to its black body. 

The Achilles tang feeds on algae, and prefers relatively shallow reef areas and turbulent waters found near wave action.



[Photograph: Convict tang]

Convict Tang (Acanthurus triostegus sandvicensis)

Also called: Convict Surgeonfish     

Hawaiian Name: Manini      

Endemic subspecies

Length: Up to 10 inches (25 cm).

The convict tang is greenish-white to yellowish-white with six narrow, vertical black bars from the head to the tail, resembling the stripes of a convict’s jail uniform. 

Large schools of convict tangs may be seen grazing on algae in the surge zone near the reef.  The post larval stage occurs in tidepools, where juveniles emerge.  The adult fish are seen at depths to about 100 feet (30 m).



[Photograph: Orangeband surgeonfish]

Orangeband Surgeonfish (Acanthurus olivaceus)

Hawaiian Name: Na‘ena‘e


Length: Up to 12 inches (30 cm).

The juvenile orangeband surgeonfish is bright yellow and similar in appearance to the yellow tang (see below).  The color of the adult orangeband surgeonfish, however, is grayish-brown to light olive (thus the species name, “olivaceus”), usually with the front of the fish being lighter in color, and then abruptly becoming darker on the rear portion of the fish.

Prominently displayed on each side of the fish is a horizontal orange band broadly ringed with blue.  The orange band extends back from the gill opening.  The base of the dorsal fin is also lined with orange.  Near the rear of the tail fin is a crescent-shaped white mark.

The orangeband surgeonfish may be seen near coral reefs, sometimes in schools, feeding on filamentous algae and detritus.



[Photograph: Yellowfin surgeonfish]

Yellowfin Surgeonfish (Acanthurus xanthopterus)

Hawaiian Name: Pualu


Length: Up to 22 inches (56 cm).

Yellowfin surgeonfish are commonly seen on Hawaiian reefs, particularly in areas where humans feeding fish are common. 

Purplish-gray in color, the yellowfin surgeonfish has irregular blue lines on the body, a yellow band over the eye region, blue bands on the dorsal and anal fins, and a black spine at the base of the tail.  The outer pelvic fins are yellow, and the blue tail fin is lyre-shaped, sometimes with a white band at the base of the tail fin.

Yellowfin surgeonfish sometimes gather in small schools, feeding on algae near the coral reef as well as over sandy areas far from the reef.



[Photograph: Yellow tang]

Yellow Tang (Zebrasoma flavescens)

Hawaiian Name: Lau‘īpala


Length: Up to 8 inches (20 cm).

The yellow tang is a thin, delicate fish with a pointed snout.  The fish is completely golden yellow except for the white sheath of its small tail spine.  The bright color of the yellow tangs allows them to be identified from shore as they swim in the shallows, particularly along the Kona Coast.  The fish also inhabit deeper waters to about 100 feet (30 m).

Yellow tangs are often seen feeding and hiding among branches of finger coral or swimming in calm waters near shore and feeding on filamentous algae.  Adult yellow tangs congregate in schools, unlike the juveniles of the species.  Juveniles are also are notable for their elevated anal and dorsal fins. 

Large schools of yellow tangs are seen only in Hawaiian waters, though the fish is seen in smaller numbers as far away as Guam and southern Japan. 

The yellow tang is the most popular Hawaiian reef fish captured for export in the aquarium fish trade.  This has heavily impacted the populations of the fish around the Hawaiian Islands.

The yellow tang’s Hawaiian name, lau‘īpala or lā‘īpala, meaning “yellow ti leaf” (lā‘ī is a contraction of lau kī, or “leaf of kī.”  (Cordyline fruticosa, ti) is a Polynesian-introduced plant. (See in Polynesian-Introduced Plants, Chapter 9.)



[Photograph: Bluespine Unicornfish]

Bluespine Unicornfish (Naso unicornus)

Hawaiian Name: Kala


Length: Up to 27 inches (69 cm).

The bluespine unicornfish is probably the most likely unicornfish to be seen by snorkelers.  It is light olive to yellowish gray in color, but darker when feeding on algae in shallow waters (but retaining a light shoulder patch).  The tail spines are bright (even fluorescent) blue, with tail streamers on males. 

The dorsal and anal fins of the bluespine unicornfish have dark bands and are blue on the margin.  A bony horn extends from in front of the eye (though may not be present in small specimens). 

Ancient Hawaiians used the skin of the bluespine unicornfish (kala) to make drum heads.  A small drum known as a pūniu, or coconut knee drum (unique to the Hawaiian Islands) was made by stretching the skin of the kala (favored for its tiny scales) over the shell of the coconut (Cocos nucifera). (See Niu in Polynesian-Introduced Plants, Chapter 9.)

In ancient Hawai‘i, sanding was done using the skin of the kala fish as well as the skin of manō (Carcharhinus species, sharks), and pumice, or ‘ana (Leiodermatium, siliceous sponge).  Sea urchin spines were used for filing.



[Photograph: Orangespine unicornfish]

Orangespine Unicornfish (Naso lituratus)

Also called: Naso Tang

Hawaiian Name: Umaumalei


Length: Up to 18 inches (46 cm).

The orangespine unicornfish has a grayish-brown body with bright orange lips.  The fish’s Hawaiian name, umaumalei (“chest garland”), comes from the curved line of yellow extending from the eye to the corner of the mouth, resembling a lei.  The snout is black in front of the yellow. 

The orangespine unicornfish’s forehead has a dull yellow mark that brightens when the fish is excited (e.g., chasing another fish), and has been likened to a flashlight shining from the fish’s forehead. 

As its common name suggests, the orangespine unicornfish has exceptionally bright orange caudal spines (which curve forward), though the fish does not have a rostral horn like some other unicornfish.

Filaments (tail streamers) extends from the top and bottom of the caudal fin in adult males.  Subadult and juvenile orangespine unicornfish are popular as aquarium fish, though adults are usually more colorful (but require a larger tank).

The orangespine unicornfish is relatively common in Hawaiian waters, and is often seen feeding on seaweed in shallow water.



Family: Labridae

There are 43 native Hawaiian wrasse species, and 13 of these wrasse species are endemic to the Hawaiian Islands.  Most wrasses are less than 20 inches (51 cm) in length.

Most wrasses are slender, brightly colored fish, usually thick-lipped with sharp, protruding, front canine teeth, smooth-edged scales, and usually a single continuous (unnotched) dorsal fin.  Wrasses primarily use their pectoral fins for locomotion, also using their tail fin when rapid movement is needed.

The body colorations of wrasses often change markedly from the juvenile to the adult stage.  Females and males also differ significantly, as do ordinary male fish compared to terminal (dominant) males.  These age and sex color variations have historically caused much confusion in determining wrasse species classifications. 

In most (if not all) wrasse species, some adult females may change sexes, becoming terminal males.  These terminal males (also called dominant males, or supermales) are usually brightly colored.  Terminal males establish territories and then spawn with females in their harem.  Relatively few wrasses become terminal males, but the ones that do are always initially born female.

Wrasses are carnivorous fish.  Some wrasse species feed on small invertebrates (e.g., hermit crabs, sea urchins, mollusks) while others prefer feeding on small fish or plankton.  Cleaner wrasses eat skin parasites off other fish species, and often have specific “cleaning stations” where fish come to be serviced (see Cleaner Wrasse section below). 

Wrasses are diurnal (actively feeding during the day), and most smaller wrasse species bury themselves in the sand at night.  Others hide in cracks and crevices in the coral reef.  Some cleaner wrasses may enclose themselves in a cocoon of mucous, something that is also done by the parrotfish.

Most wrasses are referred to by the Hawaiian term hīnālea, though many smaller wrasse species have no known Hawaiian name.  Ancient Hawaiians prepared a relish with raw, slightly decomposed hīnālea, which was salted and mixed with nuts of kukui (Aleurites moluccana, candlenut) and other ingredients.

This method of preparation was known as i‘a ho‘omelu (i‘a means “fish” and ho‘omelu refers to the partial decomposition of the wrasse—melu means “soft”).  The hīnālea relish was used as an “aftertaste” of ‘awa (Piper methysticum, kava), meaning that it was consumed directly following the consumption ‘awa. 

A person with bad breath was sometimes referred to as ipu kai hīnālea (“dish of hīnālea sauce”), which was a reference to the pungent and somewhat offensive aroma of the relish.



[Photographs: Hawaiian cleaner wrasse adult; juvenile.]

Hawaiian Cleaner Wrasse (Labroides phthirophagus)

Hawaiian Name: Hīnālea


Length: Up to 4 inches (10 cm).

The Hawaiian cleaner wrasse is known for its propensity to eat ectoparasites and mucous off other fish, which come to the wrasse’s “cleaning station” and literally wait their turn to be cleaned.  The cleaner wrasse contentedly nibbles away at the body surface of its clients, which include sharks and eels

The adult Hawaiian cleaner wrasse is bright yellow in front, tapering to blue in the back with magenta/purplish markings.  A dark stripe runs the length of the fish and through the eye region.  The anal and dorsal fins are primarily blue.

The juvenile Hawaiian cleaner wrasse is black with a blue stripe and lacks the yellow color of the adult.  The cleaner wrasse sometimes encases itself in mucus at night (see Wrasses above), as do some parrotfish species. 



[Photograph: Saddle wrasse]

Saddle Wrasse (Thalassoma duperrey)

Hawaiian Name: Hīnālea lauwili


Length: Up to 10 inches (25 cm).

Probably the most common reef fish in Hawaiian waters (and definitely the most abundant wrasse), the saddle wrasse’s body is mostly green with vertical magenta-blue lines.  The fish has an orange band behind the head and, in terminal males, a light area behind the orange band.  The head of the saddle wrasse is blue to purplish-gray shading to greenish on the lower portion.

The juvenile saddle wrasse does not have the orange band but instead has a dark horizontal stripe (on each side) running for the length of the fish, through the eye area, and to the crescent-shaped tail fin.  Beneath this dark stripe is a white stripe, and beneath the white is an orange-yellow stripe.

The saddle wrasse is very curious, and not afraid to investigate snorkelers.  The terminal male may clamp shut his crescent-shaped tail fin and hold his dorsal fin erect as he patrols his territory.  The female saddle wrasse may change sex to male (see Wrasses above), and when this occurs it is revealed by a white stripe on the side of the fish behind the orange “saddle.” 

Often seen in schools, saddle wrasses feed on crustaceans, such as crabs, as well as mollusks, worms, brittle stars, heart urchins, and sea urchins.  The saddle wrasse may also clean other fish as well as honu (sea turtles). 

An ancient Hawaiian proverb states, “Naueue ka hi‘u o ka i‘a lewa i ke kai” (“The tails of the fish that move in the sea tremble,” which is “...said of fish, such as the hīnālea, in the cold month of Welehu.  The tails of the hīnālea bend as they seek hollows in the corals for hiding.”[i]

The scientific name of the fish, Thalassoma duperrey, honors a midshipman on the L’Uranie, which arrived in the Hawaiian Islands in 1819 under the command of French Navy captain Louis Claude Desaulces De Freycinet (1779—1842). 

Various species of Hawaiian fish were collected by two of the ship’s officers, Quoy and Gaimard. (See Chapter 11, Timeline: 1819, Aug. 8.)



Family: Monacanthidae

Filefish do not have pelvic fins, and they use their dorsal and anal fins to move backwards or forwards through the water.  Most filefish species are omnivorous, and some are more than 2 feet (61 cm) long.

The family name of the fishes, Monacanthidae, translates to “One spine,” and is a reference to the first dorsal spine of the fish, which is longer than the rest and may lock in its erect position. 

‘O‘ili, the Hawaiian name used to refer to many of the native species of filefish, means “to come up,” and is a reference to the fish’s locking spine.  Filefishes are close relatives of the triggerfishes. 

  The skin of the filefish is finely abrasive.  Some filefishes are able to rapidly change color to become camouflaged with their surroundings.  Filefishes are closely related to pufferfishes (Tetraodontidae) and boxfishes (Ostraciidae).

Eight filefish species may be seen in Hawaiian waters, though one species (Thamnaconus garretti) is only seen in deep waters, and the unicorn filefish (Aluterus monoceros) is only rarely seen.



[Photograph: Fantail filefish]

Fantail Filefish (Pervagor spilosoma)

Hawaiian Name: ‘Ō‘ili ‘Uwī‘uwī


Length: Up to 7 inches (18 cm).

The body of the fantail filefish is golden yellow to yellowish-brown, with black or brown spots.  The fish is blue around the mouth and throat and has diagonal brown stripes on its head.  The fish’s colorful fan-shaped tail is yellow at the front, orange in the middle and black at the back.

When removed from the water, the fantail filefish makes a slight sound.  This led to the fish’s Hawaiian name, which means “squealing ‘ō‘ili” (‘ō‘ili refers to filefish).

            Fantail filefish populations rise and fall in cycles that are not fully understood.  The fish are sometimes among the most common reef fish in Hawaiian waters, but population peaks may be followed by large die-offs that result in fish washing up on island beaches (as occurred in 1985-1986).  Some say the cycle repeats about every 40 years.

Fantail filefish are seen in shallow waters as well as at depths of more than 100 feet (30 m).  They sometimes align themselves head-to-tail, raise and lower their spines, and spread their bright orange tails.  These behaviors may be related to courtship or territorial claims. 

In ancient Hawai‘i, the fantail filefish was said to signal the coming death of ali‘i, or royalty.  The dried fish were also used as fuel.



[Photograph: Hawaiian filefish]

Hawaiian Filefish (Cantherhines sandwichiensis)

Also called: Squaretail Filefish

Hawaiian Name: ‘Ō‘ili Lepa


Length: Up to 7 inches (18 cm).

The Hawaiian filefish is dark gray to brownish or whitish-gray in color, and is quickly recognized by the white spot at the rear of its dorsal fin (atop the base of its tail fin). 

The fish may also show pale white spots, and the rays of the fins are usually yellowish.  While the back of the tail is rounded in other filefish, in the Hawaiian filefish the back of the tail is straight. 

The Hawaiian filefish feeds on algae as well as sponges, corals, and tunicates.  The fish’s Hawaiian name, ‘ō‘ili lepa, means “flag appearing,” referring to the appearance of its dorsal fin.



[Photograph: Scribbled filefish]

Scribbled Filefish (Aluterus scriptus)

Also called: Broomtail Filefish; Scrolled Filefish; Scrawled Filefish

Hawaiian Name: Loulu

Length: Up to 36 inches (91 cm).

The scribbled filefish is bluish-gray to brownish in color, with blue to blue-green or black spots, and short pastel blue lines that appear like scribbles on the fish’s body.  The scribbled filefish can quickly take on a darker, mottled look that aids in camouflage.  The first dorsal spine is hair-like (long and slender).  About one third of the length of the fish consists of its fan-like tail fin.

Scribbled filefish feed on algae and a variety of coelenterates (e.g., coral) as well as sponges and tunicates.  They are sometimes seen in large schools, and are quite noticeable as being one of the largest Hawaiian reef fish species.

The Hawaiian name for the scribbled filefish, scriptus, means “written upon,” referring to the markings on the fish.  The Hawaiian name for the scribbled filefish is loulu, which is also the name of the endemic Hawaiian fan palms (Pritchardia species), possibly referring to the similar color of the fish, or perhaps to the resemblance of the fish’s tail to the loulu’s fan-like fronds.



Hawaiian Name: Nohu

Family: Scorpaenidae

Scorpionfish are carnivorous ambush predators, yet generally they are quite slow moving, and often sedentary.  There are 25 species of scorpionfish native to the Hawaiian Islands.

Many scorpionfish are somewhat mottled in color, with an amazing ability to blend in with their surroundings.  In contrast, some scorpionfish are brightly colored and are particularly noticeable. 

The name of the scorpionfish comes from the venomous dorsal spines found in many scorpionfish species.  These venomous dorsal spines may inflict very painful stings to humans.  In severe cases, the stings may cause allergic reactions leading to anaphylactic shock. 

Fortunately, the scorpionfish does not attack swimmers and divers.  However, it does often lay camouflaged on the ocean bottom, where it may be accidentally stepped upon. 

The recommended remedy for stings from the venomous spines of scorpionfish is to immerse the wound in hot (but not scalding) water, denaturing the venom’s protein and nullifying its toxicity.  Hunting mostly in the evening or during the night, the scorpionfish usually lies in wait and then ambushes its prey. 

Scorpionfish (family Scorpaenidae) in the Pterois and Dendrochirus genera are often referred to as lionfishes, and in Hawaiian waters there is one species in each of the two genera.  Dendrochirus barberi is known as the Hawaiian lionfish, and Pterois sphex is known as the Hawaiian turkeyfish (also referred to as lionfish). 

The fan-like fins of the lionfish are not only majestically beautiful when the fish is swimming, the fins are also used by the fish to corner and capture prey, such as crustaceans and small fish. 

The general Hawaiian name for all scorpionfishes is nohu, while the turkeyfish (Pterois sphex) is known as nohu pinao (pinao is also the Hawaiian word for dragonfly).



[Photograph: Turkeyfish]

Hawaiian Turkeyfish (Pterois sphex)

Hawaiian Name: Nohu Pinao

Also called: Hawaiian Lionfish


Length: 8 inches (20 cm).

The body of the Hawaiian turkeyfish is vertically striped with narrow pinkish-white and broader reddish-brown bars.  The pectoral fins are graced with long white spine extensions, as are the venomous dorsal spines.

During the day, the turkeyfish likes to hide in caves and under ledges (sometimes upside down), emerging at night to feed on shrimp, small crabs, and fish that inhabit the coral reefs.

Relatively shy, the Hawaiian turkeyfish often won’t move when approached.  The turkeyfish is not a particularly common fish, though it is seen more often than the Hawaiian lionfish. 

One place the turkeyfish is seen quite readily is along the island of Hawai‘i’s Kona Coast.  Unfortunately, fish collectors have decimated this species in some areas to supply the aquarium trade. 

While all Hawaiian scorpionfish are known by the Hawaiian name “nohu,” the Hawaiian turkeyfish is also known as “nohu pinao,” a reference to the appearance of the fish’s colors, and perhaps also the pectoral fins, which resemble the wings of the pinao (dragonfly).



[Photograph: Hawaiian lionfish]

Hawaiian Lionfish (Dendrochirus barberi)

Also called: Green Lionfish

Hawaiian Name: Nohu


Length: Up to 6.5 inches (16.5 cm).

The Hawaiian lionfish is greenish-brown to orangish-brown in color, mottled with white, and lined with two fairly wide and dark horizontal bars.  The fish also has a large, red ring around each eye, and rows of spots adorn its large, fan-like pectoral fins and membrane-covered spines. 

The Hawaiian lionfish is duller and better camouflaged than the turkeyfish, and also lacks the showy spines (though caution is still advised when near this fish, as wounds from the spines may be extremely painful). 

The lionfish often rests on the ocean bottom during day, beneath reef ledges, under rocks, or in caves.  At night the lionfish is more likely to venture out in the open where it may be seen.



[Photograph: Moorish idol]

Moorish Idol (Zanclus cornutus)

Hawaiian Name: Kihikihi

Family: Zanclidae

Length: Up to 8 inches (20 cm).


The Moorish idol’s body has two wide, vertical, black bars with white and golden yellow between, and at the base of the black tail.  The fish’s long third dorsal spine extends into a graceful filament that trails behind the fish.

The snout of the Moorish idol is white, with a black-edged orange spot.  The fish’s long, pointed snout is well adapted to feeding in the cracks and crevices of the coral reef environment. 

Often seen in small schools or in pairs, moorish idols prefer shallow waters as well as depths to about 100 feet (30 m).  They feed primarily on sponges, but also eat algae. 

The Moorish idol is the only existing member of its scientific family, Zanclidae, named after the Greek word “zanclon,” likely referring to the shape of the fish and its trailing filament. 

The Moorish Idol is closely related to the surgeonfishes (Acanthuridae), and they both predominantly use their pectoral fins for propulsion.




Family: Balistidae

There are eleven species of triggerfish in Hawaiian waters.  These tough-skinned fish are known by the Hawaiian term, humuhumu, which means “to sew pieces together,” and is likely a reference to the geometric shapes and patterns that adorn some triggerfishes. 

The thick, strong, first dorsal spine of the triggerfish may become erect and lock in place with the shorter, second dorsal spine. 

To dislodge the fish from a crevice where it is hiding (wedged in with its erect dorsal spine and extended pelvic bone), the second spine may be depressed to release (“trigger”) the locking mechanism.  However, this practice is not recommended as the fish has a strong mouth and jaws, and may bite. 

Triggerfishes feed mostly during the day, and have chisel-like teeth that they use to break apart their prey, which are mostly invertebrates, including sea urchins, crabs, and mollusks.  Some triggerfishes feed on zooplankton.

Triggerfish locomotion is achieved primarily using the dorsal and anal fins, and the tail fin is used when rapid movement is needed.  Triggerfishes can maneuver backwards as easily as forwards, which is a helpful trait among the many small holes and crevices in the coral reefs.  The eyes of triggerfish are located noticeably far back on the head, which further assists maneuverability.

Mostly solitary, triggerfishes are aggressively territorial.  They are known to make a grunting noise when intercostal muscles are used to move two bones in the pectoral girdle, producing a sound that resonates in the fish’s swim bladder.

The triggerfish lays its eggs in a nest on the seafloor or reef.  Relatives of triggerfishes, also in the order Tetraodontiformes, include pufferfishes (Tetraodontidae), boxfishes (Ostraciidae), and filefishes (Monacanthidae).



[Photograph: Reef triggerfish]

Reef Triggerfish (Rhinecanthus rectangulus)

Also called: Picasso Triggerfish

Hawaiian Name: Humuhumunukunukuāpua‘a


Length: Up to 10 inches (25 cm).

The reef triggerfish is Hawai‘i’s state fish, and is commonly seen in nearshore, wave-swept, reef areas at depths to about 25 feet (7.6 m).  White on the bottom and light brown to greenish above, the reef triggerfish is recognized by the colorful, geometrically arranged lines on its body.

A wide black band runs vertically through the eye and then extends diagonally toward the back of the fish.  There is a spot of blue above the mouth, red at the base of the pectoral fin and golden, triangle-shaped lines across the side of the fish toward the back, bordering a black triangle.

Gradually, a solitary fish, the reef triggerfish feeds primarily on algae, but also eats small invertebrates including crustaceans, worms and mollusks.  The eyes of the reef triggerfish are positioned high and relatively far back on the body, allowing the fish to prey on long-spined sea urchins. 

The Hawaiian name of the fish means, “humhumu with a snout like a pig.”[ii]



[Photograph: Lagoon triggerfish]

Lagoon Triggerfish (Rhinecanthus aculeatus)

Hawaiian Name: Humuhumunukunukuāpua‘a


Length: Up to 12 inches (30 cm).

The lagoon triggerfish is white on the bottom shading to a greenish-gray color above with blue lines over the eye region and a large black area in the upper center region of the body. 

Yellow lips, a yellow-orange line extending back from the mouth, and diagonal white lines on the lower rear portion of the body distinguish the lagoon triggerfish from the reef triggerfish.  The lagoon triggerfish also has less black on its body, and there are three rows of spines at the base of the fish’s tail.

The lagoon triggerfish is seen in shallow reef areas to depths of about 25 feet (8 m), feeding on algae and invertebrates.  The lagoon triggerfish may be very territorial, particularly when protecting its eggs.



[Photographs: Trumpetfish: Yellow phase; gray-brown stage.]

Trumpetfish (Aulostomus chinensis)

Hawaiian Name: Nūnū

Family: Aulostomidae


Length: Up to 30 inches (76 cm).

Of the three trumpetfish known, only Aulostomus chinensis is found in Hawaiian waters, and it is fairly common along coastal reef areas.  The trumpetfish has an elongated, inflexible, stick-like body that is narrower than deep (unlike the cornetfish, which is more flattened in shape).  The trumpetfish propels itself with its dorsal and anal fins, which are set far back on the body.

The trumpetfish has two color phases: one is bright yellow; the other is gray-brown or orange-brown with longitudinal white stripes that become black toward the back.  Also distinguishing the trumpetfish from the cornetfish are the black marks on the trumpetfish’s upper jaw, at the base of the pelvic fins, and on its fan-shaped tail fin

Feeding primarily on shrimps and fish, the trumpetfish likes to ambush its prey in a puka (hole) in the reef by using the barbel on its chin as a lure to deceive its prey.

Orienting its body in a vertical position, the trumpetfish slowly stalks its prey, maneuvering closer until, with a quick burst of speed, it jumps forward and uses its expanding mouth and vacuum-like suction power to swallow the victim.  Prey is sometimes approached by jumping out from behind the cover of other species (e.g., parrotfish, pufferfish, and surgeonfish). 



[Photograph: Cornetfish]


Hawaiian Name: Nūnū Peke

Family: Fistulariidae


Length: Up to 5 feet (1.5 m) with caudal (tail) filament.

Of the four known species of cornetfishes, two are seen in Hawaiian waters, but only Fistularia commersonii is commonly seen in nearshore waters.  The cornetfish is much larger than the trumpetfish but not quite as common. 

The cornetfish has a long, thin (horizontally flattened) body, with a long, tubular snout but relatively small mouth and tiny teeth.  The dorsal and anal fins are located far back on the body, and the cornetfish’s whip-like tail is actually a thin filament extending from the tail. 

The body color of the cornetfish is greenish above to silver beneath.  The back of the fish may flash (rapidly show) light blue bars or spots (two rows) when camouflage is necessary.  A dark-barred pattern is also sometimes seen as the fish sits on the ocean bottom, or at night.

Cornetfishes sometimes gather in small groups (4 to 6 fish) that are seen in shallow reef and rocky areas and at depths to about 80 feet (24 m).  Like the trumpetfish, the cornetfish is an ambush predator, sucking small prey into its expanding mouth, and feeding mostly on small fish and crustaceans. 

Unlike the trumpetfish, the cornetfish is flexible and uses side-to-side movements of the back of its body to help propulsion.  Also distinguishing these two quite similar appearing species is the fact that the cornetfish has no fin spines. 

Trumpetfishes, cornetfishes, seahorses, and pipefishes are all known as tube-mouth fishes, and belong to the scientific order Syngnathiformes. 



[Photograph: Milkfish]

Milkfish (Chanos chanos)

Hawaiian Name: Awa

Family: Chanidae


Length: Length: Up to 5 feet (1.5 m), rarely longer.

The milkfish (Chanos chanos) is the only species in the family Chanidae.  Silver in color with a single prominent dorsal fin, the milkfish has small scales and a large, deeply-forked tail (caudal fin). 

The milkfish has a relatively small, pointed mouth, and the pectoral fins are low on each side of the body.  Further back on the body are the pelvic fins.  The dorsal fin is somewhat shark-like, and the fish is sometimes mistaken for a shark by inexperienced snorkelers and divers.

The milkfish frequents shallow waters around coral reefs, particularly near currents, where it feeds on seaweed, phytoplankton, and algae.  The milkfish also ventures into deeper waters around the reefs. 

In ancient Hawai‘i, milkfishes were an important source of food, and were raised in loko ‘ai (fishponds) along with ‘ama‘ama (Mugil cephalus, mullet).  Milkfishes are still raised in ponds in Asia, providing an important food source.

The milkfish’s Hawaiian name differs depending on the fish’s size.  Young milkfish are known as pua awa (or puawa), while medium size milkfish are called awa ‘aua.  When they are big enough to eat they are known as awa, and large size milkfish are known as awa kalamoho.




Family: Mugilidae

Mullets have flattened heads and blunt snouts, and are silvery to gray in color.  They inhabit shallow coastal areas, including brackish waters.  They are related to barracudas, which also have two widely separated dorsal fins, though mullets lack the prominent teeth of the barracuda.  Mullets also have relatively large scales, and the tail fin may be edged with black.

Mullets filter mud and sand thorugh their gills, sifting out the organic material.  In ancient Hawai‘i, ‘ama‘ama (Mugil cephalus, striped mullet) were raised in loko ‘ai (fishponds) along with awa (Chanos chanos, milkfish). 

Both fish species were an important source of food.  Another native mullet species is uouoa (Neomyxus leuciscus; acute-jawed mullet) also called the sharpnosed mullet.  There is also a non-native (introduced) mullet species, Moolgarda engeli, now inhabiting Hawaiian waters.



[Photograph: Striped mullet]

Striped Mullet (Mugil cephalus)

Also called: Gray Mullet

Hawaiian Name: ‘Ama‘ama


Length: Up to 20 inches (51 cm), rarely larger.

An herbivore, the striped mullet has a flattened head and blunt snout, and is silver-gray on the dorsal (upper) surface but more silvery in color on the sides.

Also on the sides are light gray-brown stripes along the center lines of the scale rows.  The back edge of the caudal (tail) fin is often edged in black.  Viewed from the front, the striped mullet’s mouth has somewhat of an inverted v-shape. 

An important food source in ancient Hawai‘i, the striped mullet’s Hawaiian name differs depending on the size of the fish.  Small juveniles (finger length), are known as pua ‘ama, while hand length striped mullet are known as kahaha.  When the fish reach 8 to 12 inches (20 to 30 cm) they are known as ‘ama‘ama.  Larger (full-sized) striped mullets are known as ‘anae.

The striped mullet feeds primarily on algae and detrital material by filtering organic material from the seafloor’s sand and mud through its gills, and then expelling the inorganic sediments.



[Photograph: Acute-jawed mullet]

Acute-Jawed Mullet (Neomyxus leuciscus)

Also Called: Sharpnose Mullet; False Mullet; False ‘Ama‘ama.

Hawaiian Name: Uouoa

Length: Up to 18 inches (46 cm); rarely longer than 12 inches (30 cm).

The acute-jawed mullet has a silver body with a yellow spot at the base of the pectoral fin. 

The acute-jawed mullet feeds on algae in shallow, nearshore waters, usually preferring rocky reef areas rather than areas with a sandy bottom.  The acute-jawed mullet’s snout is sharper than the snout of the striped mullet (Mugil cephalus), and the jaw is more steeply angled (acute).




Family: Tetraodontidae

Pufferfishes have no scales or pelvic fins, and are distinguished by their bristly skin and the ability to distend (“puff”) themselves up with water.  Hawaiian names for pufferfish include makimaki, kēkē (“enlarged”), and ‘o‘opu hue (“gourd ‘o‘Pu”).

The bristly skin of an alarmed (puffed up) pufferfish is a defensive mechanism that wards off attackers, and may also be used within a hole in the reef to prohibit the fish from being pulled out.  If taken out of the ocean, the pufferfish fill up with air and make “little croaking noises.” 

Though species in the Canthigaster jactator genus (e.g., the whitespotted toby) are not particularly adept at inflating, they are able to secrete a poison that deters predators. 

Most pufferfishes contain the extremely poisonous neurotoxin called tetrodotoxin, which can cause paralysis and death if ingested.  Specially trained “fugu” chefs in Japan prepare the fish, a delicacy, so it is safe for consumption.  Trace amounts of the poison give the diner a desired warm or “glowing” feeling.



[Photograph: Hawaiian whitespotted toby]

Hawaiian Whitespotted Toby (Canthigaster jactator)


Length: Up to 3½ inches (9 cm).

Usually seen in pairs, the Hawaiian whitespotted toby is yellow-brown to dark brown and covered with white to whitish-blue spots, except on the fins.  The eyes are green, and the body may show a green fluorescence.

Inhabiting shallow reef areas, the whitespotted toby is the most commonly seen toby in Hawaiian waters.   Not a shy fish, the whitespotted toby is often curious, allowing humans to approach.  The whitespotted toby feeds on sponges, algae, tunicates, and other invertebrates.



Damselfishes (Pomacentridae)

There are about 320 species in the damselfish family (Pomacentridae), and 17 of these species are found in Hawaiian waters.  Damselfishes are one of the most common reef fish in Hawaiian waters, usually inhabiting shallow reef areas. 

Damselfishes may be brightly colored (particularly juveniles) or dull.  Damselfish that feed on plankton tend to congregate in groups above the coral reef while damselfish that feed on algae tend to be more solitary (and territorial), inhabiting shallow, rocky areas where algae grows.



[Photograph: Hawaiian Sergeant]

Hawaiian Sergeant (Abudefduf abdominalis)

Also called: Sergeant Major

Hawaiian Name: Mamo


Length: Up to 10 inches (25 cm).

The Hawaiian sergeant is light blue-green on top, light yellow on the sides, and white on the lower (ventral) surface.  Five black stripes or bars are prominent on the Hawaiian sergeant’s dorsal area but become narrower and disappear toward the ventral surface. 

Juvenile Hawaiian sergeants, which are common in tidepools, are bright yellow in color, becoming more greenish as they mature and then enter the ocean.

The sergeant’s Hawaiian name, mamo, comes from ma‘oma‘o, which means “green.”  Hawaiian sergeants are sometimes aggressive towards people who threaten their territory, darting toward the diver or snorkeler, as if to scare them away.

The Hawaiian sergeant is omnivorous, feeding primarily on zooplankton but also algae.  The fish spawns year round, and the purplish groups of eggs the female Hawaiian sergeant deposits on the reef (e.g., on plate coral or on rocks are fertilized and guarded by the male. 

The eggs are nevertheless fed on by aggressive groups of butterflyfishes, wrasses, and other reef fish, including Hawaiian sergeants.



[Photograph: Hawaiian dascyllus]

Hawaiian Dascyllus (Dascyllus albisella)

Also called: Hawaiian Domino Damselfish; Onespot Damselfish

Hawaiian Name: ‘Alo‘ilo‘i


Length: Up to 5 inches (13 cm).

The Hawaiian dascyllus is gray to black in color with bluish-white in the center of the body scales.  The juvenile Hawaiian dascyllus is generally darker (more black than gray), with a bright blue spot on the forehead and an elongated porcelain-white area on each side of the body.  This white region becomes less prominent as the fish matures.

The Hawaiian dascyllus inhabits shallow reef areas, usually around coral branches.  Adults are often seen around antler coral, and juveniles around cauliflower coral, where they feed on zooplankton. 

Adult Hawaiian dascyllus often venture into deeper waters, down to about 100 feet (30 m).  Juvenile Hawaiian dascyllus sometimes seek shelter in sand anemones, like some non-Hawaiian damselfishes (e.g., clownfishes) that have an immunity to the sea-anemone’s stinging cells.

The Hawaiian dascyllus can change (lighten or darken) its color in different circumstances (e.g., whiter in day, darker at night), and becomes almost completely white while spawning.  When the Hawaiian dascyllus is surprised or agitated, it makes a chirping sound.

[i] p. 250, Pukui, Mary Kawena.  ‘Ōlelo No‘eau: Hawaiian Proverbs & Poetical Sayings.  Honolulu: Bishop Museum Press, 1983.  Proverb 2293.

[ii] Pukui, Mary Kawena, and Elbert, Samuel H.  Hawaiian Dictionary: Revised and Enlarged Edition.  Honolulu: University of Hawaii Press, 1986.