Zebra Dartfish

The zebra dartfish is recognized by the many thin orange-pink vertical lines crossing its slender, torpedo-shaped pale green body from head to tail. The bluish markings on its face and its long, low dorsal and anal fins give it an elegant look. It belongs to the same group as dartfish such as the firefish; it hovers in the water column picking plankton and, when in danger, darts instantly into a rock crevice or its burrow.

Its most important trait is its sociability: while many dartfish species are intolerant of their own kind, the zebra dartfish lives in groups in the wild and can also be kept as a group in the aquarium. The specimens sold are wild-caught. Once settled in it is hardy, but because of its timid nature it needs a calm aquarium.

It lives over a wide range from the Red Sea to the Marquesas Islands in the eastern Pacific, on hard-bottomed parts of seaward reefs. It is usually found in shallow water with current, around 2–4 meters. It forms small or large groups; many individuals share the same shelter and hunt zooplankton just above the bottom.

• Volume: At least 250 liters for a small group; a single specimen can live in 150 liters.
• Water: Salinity specific gravity 1.023–1.026, pH 8.1–8.4, temperature 24–27°C.
• Layout: A rock structure with plenty of crevices and caves, a sand substrate and open swimming space at the front.
• Lid: Dartfish are among the fish most likely to jump out of the aquarium; a gap-free lid or a mesh lid is essential.
• Flow: It is used to moderate to strong flow.
• Reef compatibility: Reef-safe; it leaves corals and invertebrates alone.

Carnivorous; in the wild it feeds on zooplankton. Offer frozen mysis, enriched brine shrimp, copepods and fine granules. Small portions 2–3 times a day maintain color and condition. The lines of underfed specimens fade.

Peaceful, timid and fast. There are small pecking-order squabbles within the group, but serious injuries are rare. In a crowded, noisy aquarium it hides and does not come out to feed.

Good companions: Clownfish, cardinalfish, gobies, blennies, royal gramma, fairy and flasher wrasses, calm dwarf angelfish.

Avoid: Triggerfish, lionfish, hawkfish; tough damselfish and large, territorial fish keep it constantly in hiding.

Keeping it as a group is recommended: 4–5 or more individuals should be added at the same time. Adding a single individual to the group later leads to fighting. In a large aquarium a pair or a single specimen also does fine, but in a group it behaves more boldly and is seen more often.

Dartfish lay their eggs inside a burrow or rock cavity. Breeding of the zebra dartfish in the aquarium is observed very rarely; raising the planktonic fry is not a known, established practice.

• New specimens are sensitive to shipping stress; carry out quarantine in a calm, dimly lit container.
• Marine white spot and velvet: 3–4 weeks of quarantine.
• A significant share of deaths are caused by jumping.

There is no reliable external difference. During the breeding season the female's belly becomes fuller.