Hawaii’s Tropical Fish

Jun 25, 2022 | General Information

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There are few things that visitors to Hawaii enjoy more than putting on their fins and heading for the warm ocean waters surrounding Hawaii’s islands. In addition to water temperatures during the year that usually range between 74 and 80 degrees Fahrenheit, Hawaii’s waters generally are crystal clear with excellent visibility, especially in protected marine reserves on each island and Molokini. (See our article about Marine Life Conservation Districts MLCDs)

More than anything else, visitors are attracted to the colorful fish, beautiful coral formations and incredible marine life below the water’s surface. This article provides brief descriptions of just a small fraction of the species of fish that you’ll discover while snorkeling around Hawaii’s islands.In another article we will provide descriptions of
Hawaii’s coral reefs that actually are diverse ecological communities. Please remember that, although they look like rock, coral reefs actually are living animals that can be damaged or destroyed by careless snorkeling. Never walk or stand on coral or break off pieces of coral which is illegal in Hawaii.

All of the tropical fish described in this article are found in great snorkeling spots around the Hawaiian Islands. Some of the best snorkeling can be found in the state’s 11 MLCDs, some of which are located on each island. Others are found in some of the most scenic locations in Hawaii which makes snorkeling or diving in each of these locations a very different kind of experience.

In addition to snorkeling along the scenic Na Pali Coast, snorkeling tours of Kauai often are combined with visits to Ni’ihau and the turquoise waters of Lehua Crater. A small, crescent-shaped island just north of Ni’ihau, Lehua’s clear waters are home to a very large number and variety of reef-feeding fish and the island itself is a Hawaii State Seabird Sanctuary. As a sanctuary, Lehua provides habitat for at least 16 species of sea birds. In Lehua’s waters, snorkelers will commonly encounter large schools of brightly colored fish including Pyramid, Milletseed, Pennant Butterflyfish and many other Butterflyfish including Raccoon, Fourspot, Longnose and the Saddleback.

A stunning variety of tropical fish and coral diversity are found off portions of the Kona Coast of the Big Island and near the northern end of the island. Historic Kealakekua Bay is known for incredibly clear water and healthy coral reefs teeming with colorful fish. Kealakekua Bay is part of an MLCD that includes pristine waters and diverse marine life. Elsewhere in the Big Island, an abundance of tropical fish also is found near the Old Kona Airport and north from Kawaihae in the Waialea part of Kawaihae Bay and near Lapakahi State Historical Park.

Hanauma Bay on Oahu is home to hundreds of colorful fish species, sea turtles and a living coral reef with countless underwater passageways to explore. Countless visitors have confirmed that this stunning aquatic environment is unlike any other in Hawaii or even on the planet. Fortunately Hanauma Bay is one of Hawaii’s protected MLCD sites along with Pūpūkea and Waimea Bay Beach Parkson the north shore of Oahu.

Maui is unsurpassed in Hawaii for its abundance of tropical fish and variety of snorkeling sites. Honolua Bay is an MLCD located on the northwestern end of Maui. No fishing of any kind is allowed here making for a sea life density and diversity that is second to none on the Valley Isle. Night diving reveals otherwise hidden nocturnal sea creatures. In addition to snorkelers that flock to its colorful coral reefs, Honolua Bay also appeals to scuba divers, especially on the east side, looking for eagle rays and spinner dolphins.

AhihiKinau Natural Area Reserve located on the southern coast of Maui just past Makena is an MLCD a marine life conservation district with a coastline mostly made up of lava rock intermixed with coral. The abrupt contours of the sea floor make perfect homes and hiding places for aquatic life to flourish.

As for Molokini, owned by the federal government, a protected Hawaii State Seabird Sanctuary, and with its unique shape, you’ll see species of fish that you normally would not see by just snorkeling anywhere on the coastline of Maui or any other Hawaiian island. Home to about 250 species of fish and a variety of other marine life, on most days in the crystal clear water, with more than 150 feet of visibility, you’ll encounter one or another of the fish described below, including trigger fish, tangs, parrotfish, butterfly fish, trumpet fish, needle fish, wrasse, Puffer fish, angel fish, clown fish, Moorish idols and much more.

There are over 40 species of Trigger fish that inhabit tropical and subtropical oceans throughout the world. One of them, the Rectangular Triggerfish known as the Humu Humu Nuku Nuku Apua’a, became the official Hawaiian state fish in 2006. Unlike Hawaiian folks that you’ll encounter on your visit to the islands, give these fish some space when snorkeling. They can be quite territorial and don’t like to be bothered. Usually, however, they slip into holes in a reef when threatened or when resting at night.

The Pinktail Triggerfish grows up to 16″ making it one of the larger trigger fish in the family. Like other trigger fish, when threatened or upset it has unique vocalization capabilities and can be aggressive at times, for example, when protecting unhatched eggs during mating season.

With blue bands above their eyes, yellow lips and painted sides, it’s hard to mistake the Picasso Triggerfish (also known as the Humuhumu Triggerfish) for any other fish. These beautiful fish like sandy areas where they can be found along with turtles, perhaps a reef shark and octopuses.

There are 43 different fish in the Wrasse family and 13 of them are native to Hawaiian waters. Snorkelers will often see these fish following them. What are Wrasse looking for? Possibly feeding opportunities from disturbances caused by the motion of snorkelers.

The Saddle Wrasse, the most abundant reef fish in the Hawaiian Islands, gets its name from the red saddle right behind its pectoral fin. Interestingly this fish has the ability to change sexes and also has different color patterns for different stages of its life.

Snorkelers should have no problem identifying the Ornate Wrasse. Its head is red marked with borderline phosphorescent green lines; the bottom of the fish is blue, especially the belly; the scales are marked by a vertical, crescent-shaped stripe followed by blue; and if you still are puzzled, look for the black spots right behind its eyes.

Even easier to identify is the Yellow-Tail Wrasse with 3-4 four white spots surrounded in black spaced along the upper part of its body which is a rich red color. Like all other Wrasses, they live in small groups or as pairs and are able to change their sex as needed. This beautiful fish is known for being adept at rolling rocks and coral over to find its favorite prey: snails, hermit crabs, crabs, shrimps, mollusks, and sea urchins.

Small yellow and purple Hawaiian Cleaner Wrasses pick tiny animals, dead scales, parasites and diseased or damaged tissue from other fishes. They provide this service free of charge by setting up a cleaning station in a particular area of the reef where they stay quite busy cleaning other fish. For its services, the Cleaner Wrasse gets mucus and algae from fish needing its service. Easy to spot, it doesn’t need to advertise. A beautiful black stripe that runs the length of its body is outlined in a vibrant pink color.

The Bird Wrasse has a long beak-like snout which it uses to capture prey that it breaks into smaller bite-size pieces. Females are a brownish black and males are different variations of green. Part of the Wrasse family, the Hogfish gets its name from the way it uses its long snout to search out crustaceans on the sandy sea floor (think about a pig rooting through mud in search of a morsel).

The Christmas Wrasse, named for its red and green coloring, can be found primarily in shallow reefs and along rocky bottoms, going as deep as 30 feet. Growing to nearly a foot in length, it’s one of the larger Wrasse fish in Hawaiian waters.

Colorful Butterfly Fishes have deceptively small mouths that can eat lots of different coral or other small animals that float in the water. Adding to their deception, probably to confuse predators, they have a black stripe that hides its eye and even has a false eye spot near the back of its body. Which end of this fish is which?

The Ornate Butterfly Fish is easy to identify with six orange diagonal stipes on both sides of its comparatively small body that usually grows to 5-6 inches but can grow larger. A shy relative, the beautiful Threadfin Butterfly likes to hang out on inner and outer reef slopes behind rocks and coral. Another shy species is the Fourspot Butterfly that, when frightened, will dart from place to place. Two white spots surrounded in black are on the upper half of its body on each side.

The bright yellow Longnose Butterflyfish hangs out on reef flats when not in schools. A nocturnal species, the Raccoon Butterfish gets its name from black patches around its eyes that, with a good imagination, resemble a Raccoon. The Bluestripe Butterfly Fish, with 8 diagonal bright blue stripes, is a comparatively rare species found only in the Hawaiian Islands.

Many of Hawaii’s fish are social, sometimes traveling pairs or a male hanging out with several females, like the Potter’s Angelfish or the even more social Pennant Fish seen in schools of 30 or more. These fish are amicable by comparison with Lizard Fish that bury themselves in sand to wait for unsuspecting prey and then use their nasty teeth.

The most common of the Tang (or Surgeonfish) family, the Convict Tang can be found in tide pools and shallow reefs all the way down to depths of 150 feet. These distinctive fish really do look like convicts with their white bodies and black stripes. The Convict Tang averages about six inches in length and feeds on reef algae.

One of the easiest fishes to spot and identify along Maui’s reefs, the Yellow Tang’s bright yellow coloring really stands out. They can grow to eight inches and are normally found in shallow reefs.

The Achilles Tang have a distinctive orange patch near the tail and beautiful orange, white, and blue stripes that look like they were painted on. The Achilles Tang can be found in surge zones, along rocky shores and coral reefs. The tails of Achilles Tang consist of sharp spines that can cause deep wounds. Surgeonfishes (sometimes called Tangs) also have sharp spines near their tails that they use for protection.

With a horn-like growth out of the middle of its forehead, Bluespine Unicorn Tangs also have sharp spines in their tales that can cause injury if you touch them. They can grow to 24 inches and tend to feed near shallow reef surfaces.

Unlike the Bluespine Unicorn Tang, the Orangespine Unicorn Tang does not have a prominent “horn,” but an easy to way to identify these fish is by the orange band where its tail meets its body. They primarily feed in shallow reef surfaces and can grow up to 24 inches long.

Unless you look closely, this fish can be easily confused with the yellow Longnose Butterflyfish with the Forceps Butterflyfish. Both fish are bright yellow, with dark heads, and long noses. But the Forceps Butterflyfish has a slightly shorter nose and its jaw is roughly one-third shorter. The Forceps Butterflyfish feeds in shallower parts of the reef whereas the Yellow Longnose feeds in the deeper waters at the outer reef.

The black-spotted, yellow Milletseed Butterflyfish is one of the most common fish seen by snorkelers in Maui’s reefs. It has a unique, vertical black eye mask. They tend to swim in schools in both shallow and deep reefs and grow to about 6.5 inches. Normally hanging out near the inner and outer reef slopes, Threadfin Butterflyfish grow to around eight inches.

The Moorish Idol is often confused for a butterflyfish, but it’s actually a member of its own species. These fish are commonly seen by snorkelers near the sea floor around shallow reefs. Besides its coloring, another characteristic of Moorish Idols is their extremely long dorsal fin that can double the length of the fish.

The Hawaiian Whitespotted Toby Pufferfish is yellowish to dark brown with white spots. Like all pufferfish, when alarmed these fish expand their size by upwards of 2x to 3x by sucking in and holding water. They also have poisonous toxins in their skin that makes them dangerous for both predators and humans.

Long and narrow with needle-like pointy beaks, Needlefish swim near the ocean’s surface and often leap from the water. Needlefish can range from a couple of inches all the way to three feet or more.

Generally, between 6 to 14 inches long, the Orangeband Surgeonfish can be identified by a thick orange strip just above its pectoral fin. Another fairly easy identifier is their two-toned body, normally white (or lighter) in the front half of their body and grey in the back. They tend to swim in schools near the sandy ocean floor.

The list of fish that you’ll find while snorkeling around Maui goes on and on. Some of the easiest to spot include:
Parrotfishes that scrape small plants off the coral rock with their sharp beak-like teeth; Goatfishes that use a pair of feelers on their chin for searching in the sand and around rocks for small animals to eat; the White-Spotted Damsel that displays a distinctive white spot on each side of its body with the rest of its coloration a blackish blue; named for the five black stripes running vertically against its blue coloring, the Sergeant Major fish can live in waters up to 130 feet deep; and named for the spots that cover their bodies, Hawaii’s Boxfish swim mostly in shallow waters.
A marine creature that you’ll have no trouble recognizing, that’s not dangerous but can be scary, is the Yellow margin Moray Eel that often is seen in the reefs of Maui. Staying hidden in the reef during the day, they are sometimes difficult to spot even though they can grow to four feet in length. As with everything under the sea, simply stay back a respectable distance and don’t antagonize them.