Yellow Longnose Butterflyfish (Forceps Fish)

The yellow longnose butterflyfish is a very common butterflyfish. It and its rather uncommon relative, the big longnose (Forcipiger longirostris) have one of the longest Hawaiian fish names, lau-wiliwili-nukunuku-'oi-'oi. Its meaning is "leaf of the wili-wili tree with a sharp nose." The hue of the fish is similar to the coloring of the big, billowy leaves of the Hawaiian wili-wili tree. This fish is prevalent in southern Hawaiian waters by Maui and Hawaii Island.

Characteristics

Origin and Distribution

This fish is found from Hawaii and the Revillagigedo Islands southward into eastern and central Polynesia and then westward across the tropical Pacific Ocean, through the East Indies, and across the Indian Ocean to the coast of Africa and the Red Sea.

These butterflyfish spend most of their time near exposed seaward reefs where there is lots of coral growth, rocky caves, and ledges, and they are also found in lagoon reefs. They inhabit depths from between 3 to 476 feet with environments that include everything from shallow flats to very deep walls. They are usually seen in pairs though sometimes seen in small groups of as many as five individuals, and occasionally they are seen alone.

Colors and Markings

The yellow longnose butterflyfish has a disc-like shaped body that is laterally compressed and it has a long protruding snout tipped with a small mouth. The dorsal fin is continuous and it has a rounded tail fin. This fish has a bright yellow body as well as yellow dorsal, anal, and pelvic fins. There is a black bar over the nape covering the upper half of the eyes, giving a mask-like appearance. The rear edge of the dorsal and anal fins can be edged in blue and there is a prominent eye-spot on the anal fin just below the caudal peduncle. The pectoral and caudal fins are transparent.

The yellow longnose species has a shorter snout with a larger mouth at the end than its big longnose butterflyfish counterpart. These fish are named forceps fish, which stems from Latin forcipiger, meaning "forceps bearing." The mouths of both types of fish resemble a pair of surgical forceps. These fish use their elongated mouths to pluck invertebrate prey out of coral reef crevices.

The two species can also be identified correctly by counting their dorsal spines. The yellow longnose butterflyfish usually has 12 spines and from 22 to 24 soft rays, while the big longnose usually has 12 spines and from 25 to 28 soft rays.

Tankmates

In general, it is a peaceful fish. Butterflyfish are usually best kept singly or in larger aquariums as a mated pair. It does better with other non-aggressive fish, but can be placed into a moderately-aggressive community if introduced into the aquarium first. Smaller non-aggressive fishes like cardinalfish, gobies, tilefish, fairy basslets, fairy and flasher wrasses are good candidates as tank mates. Also, larger and rather territorial angelfish can be kept together with this species. 

It can be kept with some of the other butterflyfish but will be aggressive towards other members of its own kind, as well as other butterflyfish in its same genus. Small but very territorial fishes like dottybacks should be avoided. Also, fish like bass or scorpionfish, even if they are small enough, should be avoided.

Habitat and Care

Yellow longnose butterflyfish need plenty of shelter and room to swim around. These fish prefer rockwork, preferably well developed live rock, that has caves or overhangs. They also need moderate water movement.

This fish is not recommended for reef-type aquariums since it is a known coral eater. They are best kept in "fish only" aquariums. It will need a well established, matured for at least six or more months, tank.

This fish is sensitive to even the lowest levels of ammonia and other changes in its environment that result in poor water quality. Sudden massive water changes can cause trouble. Consider water changes at 10 percent biweekly or 20 percent monthly. 

Yellow Longnose Butterflyfish Diet

Yellow longnose butterflyfish are omnivorous but are primarily meat eaters. In the wild, it is found in areas with abundant corals, picking in between coral heads with its long snout. It feeds on a wide variety of invertebrates including stony coral polyps and soft coral polyps as well as small animal prey including crustaceans.

In the aquarium, offer meaty foods, dried flakes, prepared frozen foods, shrimp, and tablets. It may enjoy eating live brine shrimp but should be fed as many different foods as it will eat, as it will not thrive on that diet alone. The yellow longnose can adapt to eating typical aquarium butterflyfish fare rather quickly. Several sponge-based frozen foods are now available and can also be fed to butterflyfish. Vegetables like Japanese nori seaweed may also be favored. Feed it at least twice a day. If it is a tiny juvenile, food should be provided frequently in small quantities three or four times every day. Because it is such as thin bodied fish, if this fish is not provided with an adequate and ample diet, it can easily starve in captivity.

Sexual Differences

No sexual difference is noted for this species. These fish are gonochoristic, meaning that each fish is either a male or a female (they do not morph into another sex at any point in their life).

Breeding the Yellow Longnose Butterflyfish

This species has not been successfully spawned or cultivated in captivity. In the wild, like many other marine organisms, butterflyfish reproduce by external fertilization. They are pelagic, or egg scatterers that release many tiny eggs into the planktonic water column where they float with the currents until they hatch. Once hatched, the fry are in a post-larval state. Their body, extending from the head, is covered with large bony plates.

More Pet Fish Breeds and Further Research

If yellow longnose butterflyfish appeal to you, and you are interested in similar fish for your aquarium, read up on:

• Angelfish
• Gobies
• Wrasses

Check out additional fish breed profiles for more information on other saltwater fish.