Yellow Assessor

The yellow assessor is a small, elegant cave fish with a bright yellow body from head to tail, long dorsal and anal fins and a deeply forked tail. It belongs to the same family, Plesiopidae, as the marine betta (Calloplesiops altivelis), which has its own page on the site. In the wild it lives on the Great Barrier Reef and in Papua New Guinea, in caves, crevices and beneath rock overhangs at depths of 5–20 meters, often in groups swimming upside down. In the aquarium it is a hardy species that is easy to feed; the male carrying the eggs in his mouth can be observed in the aquarium as well.

• At least 110 liters for a small group.
• Salinity specific gravity 1.023–1.026, pH 8.1–8.4, temperature 24–27°C.
• Reef-safe: it leaves corals, shrimp and snails alone.
• Plenty of caves and rock overhangs; shaded ceilings under which it can hang upside down.
• A covered aquarium is recommended.

Carnivorous. Offer frozen mysis, brine shrimp, copepods and fine granules. It likes catching food from the water column; feed small amounts twice a day.

Peaceful and somewhat shy; it stays around its cave. Individuals added at the same time get along as a group, while an unfamiliar individual added later may be chased.

Good companions: Clownfish, cardinalfish, gobies, blennies, fairy wrasses, blue assessor, ornamental shrimp.

Avoid: Cave-dwelling fish such as dottybacks and grammas (in a small aquarium), hawkfish, predators such as lionfish.