Four-Line WrassePseudocheilinus tetrataenia

About the Four-Line Wrasse

Four-line wrasse is the gentler cousin of six-line — same Pseudocheilinus genus, similar striped pattern, smaller (3") and less aggressive. Good alternative for keepers who want six-line behavior in a smaller package. Reef-safe with corals.

Native range: Indo-Pacific. Wrasses (family Labridae) are one of the most diverse and successful fish families on coral reefs — approximately 600 described species worldwide, of which 40-60 are commonly available in the marine aquarium trade. The Four-Line Wrasse is part of the Wrasse (Labridae) - Pseudocheilinus grouping, characterized by elongated body shape, terminal-phase sex change (most species), and active reef-grazing or pest-control behavior.

Tank requirements and aquascape

Tank size: 40 gallons. Sand substrate is non-negotiable for sand-sleeping wrasse genera (Halichoeres, Macropharyngodon, Anampses) — 2-3 inches of fine pool-filter sand minimum. Rockwork should provide multiple cave entrances and tight crevices the fish can wedge into for sleeping or escape. Lid: tight-fitting, gap-free. Wrasses are the second-most-common jumping casualties in reef tanks after gobies — a single 1cm gap is enough.

Flow: moderate to moderately strong is preferred by most wrasses — they evolved on current-swept reefs. Lighting: standard reef LED works for all wrasses; the fish itself does not require special spectrum.

Diet and feeding

Carnivore — mysis, brine, pellets. Most wrasses have very high metabolic rates and need 2-3 feedings daily. Skipping feedings during business travel or vacations leads to rapid condition loss — schedule automatic feeders or vendor-trusted tank-sitters for extended absences.

Compatible tank mates

Safe: Most reef-safe community.

Avoid: Other Pseudocheilinus, very small timid fish.

Breeding

Not captive bred. Most wrasses are protogynous hermaphrodites — born female, transition to male as they reach social dominance in a group. Tank breeding of wrasses is rare due to the complex behaviors and pelagic egg-laying that resists captive replication.

Common problems and solutions

Mild aggression to small additions.

Frequently asked questions

How is four-line wrasse different from six-line?

Four lines instead of six. Smaller adult size (3" vs 3.5"). Less aggressive.

Is four-line wrasse a good nano reef fish?

A 40-gallon tank is the practical minimum due to active swimming.

How much do four-line wrasses cost?

$40-80 in US trade.

Can I keep four-line and six-line together?

Generally no — they will treat each other as territorial rivals.

Related wrasses