Common name: Blacktip cardinalfish

General information

The Half-lined Cardinalfish, scientifically known as Ostorhinchus semilineatus, is a small and attractive species popular among aquarists for its peaceful demeanor and striking appearance. This species is characterized by its silver body with a distinctive black lateral line that extends from the gill cover to the tail, punctuated by a series of vertical half-lines below.

Native to the Indo-Pacific region, these fish are nocturnal by nature and tend to be more active during the evening or at night. In the wild, they are often found in schools, hovering in and around coral reefs and rocky outcrops.

Care

In the aquarium, Half-lined Cardinalfish require a well-established tank with plenty of hiding places and a peaceful community. They thrive in a stable environment with consistent water quality. These fish are not overly demanding when it comes to diet and will accept a variety of foods, including small pellets, frozen or live brine shrimp, and mysis shrimp.

Reproduction

Like many cardinalfish, Ostorhinchus semilineatus exhibits mouthbrooding behavior. The male will carry the fertilized eggs in his mouth until they hatch, providing protection from potential predators. This fascinating reproductive strategy can sometimes be observed in the home aquarium, offering a unique spectacle for the hobbyist.

Habitat

Half-lined Cardinalfish are typically found in the warm, tropical waters of the Indo-Pacific, from the eastern coast of Africa to the western Pacific Ocean. They prefer shallow reef environments, often at depths ranging from just below the surface to about 20 meters.

Their natural habitat includes areas with abundant coral growth and rocky crevices, which provide shelter during the day. In the aquarium, replicating this environment with live rock arrangements and dim lighting can help mimic their natural conditions and encourage natural behaviors.