Fourline Cardinalfish

Ostorhinchus doederleini

The Fourline Cardinalfish is a small reef fish found in subtropical regions of the western Pacific Ocean, from Japan to Taiwan, and extending south to Australia and New Caledonia. It is easily identified by its pinkish to brownish body adorned with four distinct brown stripes running nearly the full length from head to tail. A notable feature is the black spot at the base of its tail. These fish reach a maximum length of about 14 centimeters. This species inhabits rocky coastal areas, often found near ledges and caves, where it is most active at night. During the day, it seeks shelter in rock crevices or caves. The Fourline Cardinalfish feeds primarily on invertebrates, with a preference for gammarid amphipods. Breeding behavior is quite unique, as the fish are solitary except during the breeding season when they form short-lived pairs. The male is responsible for mouthbrooding the eggs, which involves carrying them in his mouth until they hatch. This species is assessed as Least Concern by the IUCN.