Yellow Cardinalfish

Ostorhinchus luteus

Also known as Apogon luteus, Yellow Cardinal

SaltwaterFish

Yellow Cardinalfish (Ostorhinchus luteus) — Debra Baker · CC BY 4.0

Care at a glance

Temperature: 73–79°F (23–26°C)
pH: 8.1–8.4
Adult size: 2 in (5 cm)
Minimum tank: 20 gal (75 L)
Temperament: Peaceful
Social behavior: Social
Swim level: Middle
Difficulty: Easy
Breeding: Medium
Rarity: Rare
Reef safe: Reef safe
Origin: Western Pacific (Micronesia to Fiji)
Family: Apogonidae

Overview

Keep this tiny cardinalfish in a group of three or more with peaceful tankmates, since singles tend to hide. It rests under cover by day and grows bolder toward evening, so a feeding after the lights dim is appreciated. Small meaty frozen foods and fine pellets suit its mouth size.

In the wild

The yellow cardinalfish clusters under ledges, in holes and among the spines of sea urchins on Western Pacific reefs from Micronesia to Fiji, from the shallows down to about 49 meters. It was first collected in the lagoon at Enewetak Atoll in the Marshall Islands. In the aquarium a group wants 75 liters or more with plenty of overhangs to gather beneath.

Good to know

Ostorhinchus luteus was described in 1998 and is one of the smallest cardinalfish in the hobby at about 5 cm. The body is a plain golden yellow without stripes or spots. As in the rest of the family, the male carries the fertilized eggs in his mouth until they hatch.

Did you know

Wild yellow cardinalfish almost never reach the aquarium trade, so nearly every fish offered comes from hatchery lines that began with ORA's first captive breeding in 2017.