Six Line Wrasse (Pest Patrol)

The Six Line Wrasse (Pseudocheilinus hexataenia) is a small, hyper‑active, semi‑aggressive reef wrasse known for its bold striping, relentless movement, and reputation as both a helpful pest‑hunter and a potential terror in smaller tanks. It’s hardy, beautiful, and useful — but absolutely not a “beginner‑peaceful” wrasse. Appearance Six Lines are unmistakable: a purple‑blue body with six bright orange horizontal stripes, a greenish face, and a neon‑blue tail edge. They stay small — about 3 inches — but their personality is anything but. Natural Habitat They come from Indo‑Pacific coral reefs, weaving through dense rockwork and rubble in search of tiny prey. Their natural environment is tight, complex structure — which explains their constant darting and investigative behavior in aquariums. Behavior & Temperament This is where the Six Line becomes controversial. They are: • Extremely active • Highly territorial, especially as they mature • Known to bully peaceful wrasses, gobies, blennies, and new additions • Often model citizens for months… then suddenly become dominant In larger, rock‑heavy systems they behave better. In smaller tanks, they can become the “tiny tyrant” of the reef. Aquarium Requirements Six Lines are hardy and adaptable, but they need the right environment to avoid aggression problems. They do best with: • 40+ gallons (more space = less aggression) • Lots of rockwork for weaving and hunting • A tight lid — they jump • Established systems with microfauna They are excellent at navigating tight spaces, so complex aquascapes help diffuse territorial behavior. Diet In the wild, they hunt constantly for: • Copepods • Amphipods • Flatworms • Small crustaceans In captivity they readily accept: • Frozen mysis • Brine shrimp • Small pellets • Reef plankton blends They are also valued for eating pest flatworms and pyramidellid snails, though this is not guaranteed. Compatibility This is the most important consideration. Six Lines are best kept with: • Semi‑aggressive fish • Larger wrasses • Tangs • Damsels • Angels They often harass: • Fairy and flasher wrasses • Gobies • Blennies • Firefish • New tankmates added after them They should be added last in most stocking plans. Hardiness Six Lines are very hardy, disease‑resistant, and long‑lived. Their only real downside is their temperament — which can be a deal‑breaker in peaceful community reefs.