Four-line Wrasse

Geographical Origin and Habitat: This species is native to the coral reefs of the Indo-Pacific Ocean, ranging from the Ryukyu Islands to Hawaii, the Marshall Islands, and the Tuamotu Archipelago. It typically lives among coral branches at depths between 6 and 44 meters.

Taxonomy and Morphology: Belongs to the family Labridae, genus Pseudocheilinus. The body is elongated and laterally compressed, reaching a maximum size of about 7.5 cm (3 inches). It features distinctive red eyes split by a white stripe.

Social Behavior: Solitary and markedly territorial towards conspecifics or similar wrasses. Swims actively through rockwork in search of small crustaceans.

Coloration and Sexual Dimorphism: Features four bright horizontal neon-blue stripes over a red-orange body that fades to olive green on the belly. Sexual dimorphism is not prominent, though dominant males may display brighter colors during courtship.

Aquarium Setup: Requires a tank of at least 100 liters with abundant live rock providing numerous caves and crevices for shelter. A tight-fitting lid is essential to prevent jumping.

Diet and Feeding: Active carnivore. In captivity, it consumes mysis, frozen brine shrimp, small pellet foods, and naturally controls small pests like flatworms and parasitic snails.

Water Quality: Requires stable marine parameters: temperature of 24-27°C (75-81°F), stable pH between 8.1 and 8.4, specific gravity between 1.022 and 1.025, GH 15-25, and KH 8-12.

Compatibility and Cohabitation: Reef-safe. May harass small ornamental crustaceans like shrimp and target similar small wrasses, but is completely ignored by corals.

Aquarium Breeding: Extremely rare in the aquarium hobby. Releases pelagic eggs into the water column; larval rearing is highly technical and requires specialized live food cultures.

Risks and Diseases: Robust fish once acclimated. Can suffer from ectoparasites like Cryptocaryon irritans under stressful conditions. High risk of jumping when startled.