Banana Fish

The Banana Fish (Pentapodus emeryii, commonly traded as Pentapodus nemurus) is a sleek and colorful marine aquarium fish prized for its vivid blue-to-silvery coloration and contrasting yellow longitudinal stripes. The upper body may display rich blue or lavender tones while the underside is considerably lighter, creating a bright, streamlined appearance. Younger specimens are often particularly colorful, with some of that intensity becoming more subdued as the fish matures.

Native to the Western Pacific, including the Philippines, Indonesia, and northwestern Australia, this species inhabits clear coastal reef slopes and reef-associated areas. It spends much of its time swimming close to reef structure and the substrate while searching for small fish, crustaceans, worms, and other benthic prey.

Reaching approximately 14 inches as an adult, the Banana Fish is best suited to a spacious saltwater aquarium with substantial open swimming room. It can be maintained in a large reef aquarium or fish-only aquarium, but its predatory feeding habits require careful selection of smaller fish and ornamental invertebrates.

Quick Care Guide

Care Level: Moderate
Minimum Tank Size: 180 gallons
Temperament: Semi-aggressive
Diet: Carnivore
Reef Safe: With Caution
Region: Western Pacific – Philippines, Indonesia, and northwestern Australia
Scientific Name: Pentapodus emeryii
Trade Synonym: Pentapodus nemurus

Tank Requirements

Provide a large aquarium with generous open swimming space and a combination of established rockwork, caves, ledges, and sandy or rubble areas. This active species benefits from a long aquarium footprint that allows uninterrupted cruising while still providing secure retreats when startled.

An open sandbed is useful because the fish naturally investigates areas close to the substrate while searching for food. Rock structures should leave clear swimming lanes rather than creating an overly dense aquascape.

Moderate to strong water movement, good oxygenation, efficient biological filtration, and consistent maintenance are recommended. A secure lid is advisable, particularly during acclimation or when the fish is startled.

Diet and Feeding

The Banana Fish is a carnivore that naturally feeds on small fish, crustaceans, brittle stars, marine worms, and other benthic animals.

In captivity, offer a varied selection of mysis shrimp, enriched brine shrimp, krill, chopped shrimp, clam, scallop, squid, and appropriately sized pieces of marine fish. High-quality sinking marine pellets and frozen carnivore blends can also be incorporated once readily accepted.

Feed smaller portions once or twice daily. Newly introduced specimens may initially be hesitant feeders, so offering highly palatable frozen foods such as mysis or finely chopped marine seafood can help encourage a feeding response.

Temperament and Tankmates

The Banana Fish is generally not highly territorial toward unrelated species, but it is an opportunistic predator. Any fish small enough to be swallowed should be considered at risk as the Banana Fish grows.

Suitable tankmates include tangs, rabbitfish, medium to large angelfish, larger wrasses, and other peaceful to moderately assertive marine fish that are too large to be viewed as prey. Avoid very small gobies, dartfish, tiny cardinalfish, and similarly sized species.

This species may occur singly or in groups in the wild. A single specimen is the most practical choice for most home aquariums, while keeping multiple individuals requires considerably more swimming space and filtration capacity.

Reef Compatibility

Reef Safe: With Caution.

The Banana Fish does not normally feed on corals, making it compatible with many coral-dominated displays. Its main reef compatibility concern is predation on smaller animals rather than direct coral damage.

Ornamental shrimp, small crabs, brittle stars, worms, and other suitably sized benthic invertebrates may be eaten. Very small reef fish may also become prey as the Banana Fish matures. For this reason, it is best suited to reef systems where the livestock has been selected with its predatory nature in mind.

Water Parameters

Temperature: 75–80°F
Specific Gravity: 1.024–1.026
pH: 8.1–8.4
Alkalinity: 8–12 dKH

Stable water quality is more important than maintaining one exact value within these ranges. Consistent salinity, temperature, and pH, along with good oxygenation and filtration, will support successful acclimation and long-term health.

Common Considerations

• Can reach approximately 14 inches and requires substantial open swimming space as an adult.

• Small fish, ornamental shrimp, worms, and other benthic invertebrates may be viewed as prey.

• Juveniles may display brighter blue and yellow coloration than mature specimens.

• A secure aquarium lid is recommended, particularly during acclimation.

• Usually best maintained singly unless an exceptionally large aquarium can accommodate multiple adults.