Sunset Wrasse

Sunset Wrasse

The Sunset Wrasse (Thalassoma lutescens), also called the yellow-brown or green moon wrasse, is a dazzling, energetic fish — males glow in green and yellow with a pink-streaked face, while females and juveniles are a warmer yellow. A close relative of the moon wrasse, it is hardy and always on the move, but like its cousins it grows large, becomes increasingly aggressive with age, and has an appetite for small invertebrates.

It is a superb fish for a robust fish-only or fish-with-hardy-coral system, less so for a delicate reef.

Natural Habitat & Origin

Thalassoma lutescens is widespread across the Indo-Pacific, where it ranges actively over coral and rocky reefs and reef flats, hunting small invertebrates with restless energy. Like many wrasses it dives into the sand to sleep and to escape danger.

In the aquarium it wants open swimming space and live rock with crevices, plus a fine sand bed it can bury into.

Care Requirements

Maintain stable marine conditions: salinity around 1.024–1.026, pH 8.1–8.4, and a temperature of about 24–26°C (75–79°F). Reaching about 25 cm (10 inches) and extremely active, it needs a roomy tank of around 340 litres (about 90 US gallons) or more with plenty of swimming room and a sand bed. A secure, gap-free lid is essential — it is an accomplished jumper. It is exceptionally hardy once settled.

Diet & Feeding

The Sunset Wrasse is a carnivore, feeding on small invertebrates and zooplankton in the wild. It eagerly accepts aquarium foods: offer frozen mysis and enriched brine shrimp, finely chopped seafood and quality marine pellets, fed once or twice a day. It is a voracious, reliable feeder.

Behavior & Temperament

This is a semi-aggressive fish that becomes noticeably more territorial and assertive as it grows, often dominating tankmates in a smaller system. It is best added later to a community of robust fish, and only one should be kept per tank. Its boundless energy means it is rarely still.

Tank Mates

House it with other robust marine fish — tangs, larger wrasses, angelfish, triggers (with care) and similar — that can hold their own. Avoid small, timid fish that may be harassed or eaten. It is not reef-safe with mobile invertebrates: it will hunt ornamental shrimp, small crabs, snails and worms, and may disturb corals as it crashes around, so it is best in fish-only or fish-with-hardy-coral setups.

Breeding

Thalassoma lutescens is a protogynous hermaphrodite and pelagic spawner; rearing the larvae is beyond the home aquarium, so trade specimens are wild-collected.

Common Health Issues

The Sunset Wrasse is among the hardier marine fish, but it can still contract marine ich (Cryptocaryon irritans) or marine velvet (Amyloodinium ocellatum) under stress. Quarantine new arrivals, keep water quality stable, provide a sand bed for sleeping, and secure the lid against jumping. Mindful of its growth, aggression and appetite for invertebrates, it is otherwise an easy, brilliantly coloured and active fish for a robust marine community.