---

title: "Six-Line Wrasse: The Complete Reef Care & Pest-Control Guide" description: "The definitive six-line wrasse (Pseudocheilinus hexataenia) care guide: reef pest control of bristleworms and parasitic snails, managing its aggression, diet, and tank mates." slug: six-line-wrasse commonName: Six-Line Wrasse scientificName: Pseudocheilinus hexataenia family: Labridae order: Labriformes difficulty: Beginner minTankSize: 30 temperature: "75–82°F (24–28°C)" ph: "8.0–8.4" hardness: "Marine — SG 1.020–1.026" lifespan: "4–6 years" maxSize: "3 inches (8 cm)" origin: "Indo-Pacific" publishedAt: "2026-06-05"

Six-Line Wrasse: The Complete Reef Care & Pest-Control Guide

The six-line wrasse is the busy little workhorse of the reef tank — a jewel-toned, fast-darting wrasse striped electric blue over orange that hunts reef pests like bristleworms and parasitic snails while adding constant colour and activity. Pseudocheilinus hexataenia is hardy, reef-safe, and inexpensive, making it a popular nano-reef fish. The catch is temperament: it's assertive for its size and can harass peaceful tank mates, so it needs to be stocked thoughtfully — usually added last, with plenty of rock to patrol.

This guide is the complete reference: six-line wrasse biology, its pest-control value, managing its aggression, diet, and tank mates.

---

Species Overview

The six-line wrasse (Pseudocheilinus hexataenia) is a small, active wrasse reaching about 8 cm (3 inches). It's beautifully marked with six horizontal electric-blue lines running along an orange-to-purple body, with a small false eyespot near the tail. It's a fast, constantly-moving fish that darts through rockwork all day.

The six-line is hardy, reef-safe, colourful, and a useful pest-hunter — it actively hunts copepods, bristleworms, and pyramidellid (parasitic) snails through the rockwork, providing genuine reef pest control. But it's semi-aggressive/assertive for its size, and in smaller tanks it may harass shy, slow, or peaceful tank mates — so it's "reef-safe but not always fish-safe." It's rated beginner-friendly on care, with the main consideration being its temperament and stocking. With good care it lives 4–6 years. For a reef with a pest problem and robust enough tank mates, it's an attractive, hardworking, hardy addition.

---

Natural History and Origin

Pseudocheilinus hexataenia ranges across the Indo-Pacific, living in coral-rich reefs where it darts through branching coral and rockwork hunting small invertebrates. It's a constantly-active fish that patrols its territory, picking copepods, worms, and tiny crustaceans from the reef structure, and it shelters in crevices, even spinning a mucus cocoon at night like some other wrasses.

This active, hunting, territorial lifestyle defines both its value and its drawbacks in the aquarium. Its appetite for bristleworms and pyramidellid snails (which parasitise clams and snails) makes it a useful biological pest controller, and its constant copepod-hunting reflects a healthy appetite. But its territoriality and assertiveness — natural traits for defending a reef patch — translate into aggression toward shy or similar fish in the confines of a tank, especially smaller ones. Its energy, hunting, and feistiness all stem from this active reef-patrolling natural history.

---

Water Parameters

Six-line wrasses are hardy and adapt well to stable reef conditions. Mix salt with RO/DI water, target salinity with a refractometer, and add them to a fully cycled, mature tank (a mature reef also supplies the copepods and pests they hunt) — confirm with the nitrogen cycle tracker and the water parameters reference.

---

Tank Setup Guide

Tank size

A six-line wrasse is comfortable in a 30-gallon (115-litre) reef, with more space helping to dilute its aggression toward tank mates. While small, its assertiveness means a too-small or sparse tank concentrates conflict.

Aquascape — plenty of rock

Provide abundant live rock with caves and crevices for the wrasse to patrol, hunt through, shelter in, and sleep in. This rockwork is essential both for its hunting/pest-control behaviour and for managing aggression (broken sightlines and territory let other fish stay clear). A mature reef with plenty of structure suits it best.

Filtration, flow, lid

Run a standard reef system with moderate-to-good flow. A lid is recommended — wrasses are jumpers. A mature, rock-rich reef brings out its hunting behaviour and gives tank mates refuge from its assertiveness.

---

Feeding Guide

Six-line wrasses are carnivores that hunt continuously and also take prepared foods.

What to feed

• Reef pests — bristleworms, pyramidellid (parasitic) snails, and other small invertebrates it hunts naturally.
• Copepods and amphipods from a mature reef — a natural food source.
• Frozen mysis and enriched brine shrimp — readily taken staples.
• Marine pellets/flake — most six-lines accept prepared foods.

How often

Feed once or twice daily with prepared/frozen foods, supplementing the pests and pods it hunts. A mature reef provides natural prey, but always offer proper food too. A healthy six-line is constantly active, brightly coloured, and full-bodied. Note that as it controls the tank's pest/pod population, supplemental feeding becomes more important.

---

Behaviour, Aggression and Tank Mates

The six-line wrasse is active, hardy, reef-safe, and a useful pest-hunter — but assertive and territorial for its size, which is the defining husbandry consideration. As it settles in, it establishes a territory and can harass shy, slow, or peaceful fish, and it's especially likely to bully smaller newcomers or similar small wrasses. This makes it "reef-safe" (no harm to corals/inverts) but not always "fish-safe" in a smaller or peaceful community.

Management strategies: add the six-line last (so it doesn't establish dominance before tank mates settle), provide ample rockwork to break sightlines, choose robust tank mates that can hold their own, and avoid keeping it with very shy/slow fish (like firefish or mandarins) in smaller tanks. Good tank mates include percula clownfish, yellow tang, flame angelfish, foxface rabbitfish, and other robust reef fish. Keep only one six-line per tank (they fight their own kind). Use the compatibility checker and stock thoughtfully around its temperament.

---

Breeding Guide

Six-line wrasses are not bred in home aquaria — like most wrasses, they're pelagic spawners whose tiny larvae are extremely difficult to rear, requiring specialised larval systems and foods beyond practical home setups. They're protogynous (can change sex), as many wrasses are, but home breeding isn't achievable for hobbyists.

For keepers, the six-line is a hardy display and utility fish to enjoy for its colour, activity, and pest control rather than a breeding project. Its ready availability comes from wild collection; choosing healthy specimens and quarantining them is the practical focus.

---

Health and Disease

Six-line wrasses are hardy, with the usual marine concerns reduced by quarantine and stability.

Marine ich (Cryptocaryon) and velvet (Amyloodinium) can affect them — treat in quarantine with appropriate therapy (note wrasses can be sensitive to copper, so research dosing). Bacterial infections follow poor water or injury. Jumping is a real risk — keep a lid. Otherwise they're robust; their constant activity and hunting are signs of good health, while hiding or lethargy signal a problem.

Prevention: quarantine new fish, keep parameters stable, feed a varied diet, provide ample rockwork, and use a lid against jumping. Given those, the six-line wrasse is a hardy, active, long-lived reef fish.

---

Interesting Facts

• A reef pest-hunter. Six-line wrasses hunt bristleworms and parasitic pyramidellid snails, providing useful biological pest control.
• Reef-safe but feisty. Harmless to corals and inverts, but assertive enough to harass peaceful fish — reef-safe, not always fish-safe.
• Six electric lines. Its six horizontal blue stripes over an orange body make it a jewel of the nano reef.
• Jumpers. Like many wrasses, they jump — a lid is important.
• Add it last. Introducing the six-line after other fish helps prevent it from dominating the tank.

---

Bringing It Together

The six-line wrasse is a colourful, hardy, hardworking reef fish that earns its place by hunting bristleworms, parasitic snails, and copepods — useful pest control wrapped in jewel-toned activity. The key to keeping it well is managing its assertive, territorial temperament: add it last, provide plenty of live rock to patrol and to break sightlines, choose robust tank mates (not shy, slow fish like firefish or mandarins in small tanks), and keep only one per tank. Feed it frozen and prepared foods alongside the pests and pods it hunts, and use a lid against jumping. Reef-safe but feisty, it's an excellent choice for a reef with a pest problem and sturdy companions like the yellow tang, flame angelfish, and percula clownfish. Plan the build with the AI Tank Blueprint generator and the compatibility checker.