The Four Line Wrasse is a beautiful fish but is quite secretive, shy and quick… making it a difficult fish to collect!

Being active small colorful fish, the lined wrasses are popular for a small marine aquarium. They are quite hardy, disease resistant, and long lived. The aquarium care and behavior of the Four Line Wrasse is very similar to that of the Six Line Wrasse. Once acclimated both these fish will even take care of a few pests in the aquarium, like the pyramidellid snails and commensal flatworms some coral keeping aquarists have to deal with at times. They are considered reef safe as they will not harm corals or coral anemones.

Though they are shy secretive fish in the wild, once they become acclimated to the home aquarium they become quite boisterous. They are fine in a community tank but will become aggressive towards shy timid species in the same aquarium, and sometimes even larger fish. To prevent confrontations it is best to keep it with similar sized or larger semi-aggressive fish and to make a single lined wrasse the last addition to the aquarium. They do not co-habitat well with other lined wrasses.

The Four Line Wrasses are excellent hiders and love to have live rock with plenty of retreats. They are diurnal, which means they are active by day and sleeping at night. As with all fish in this genus they sleep in a mucus cocoon, which fortunately does not seem degrade the water quality. It is thought that the cocoon protects them from predators as they sleep by masking their scent. In nature they are found with a coral called Pocillopora meandrina.

For more Information on keeping this fish see:
Guide to a Happy, Healthy Marine Aquarium

Four Line Wrasse, Pseudocheilinus tetrataenia

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FourLine Wrasse in a holding tank with several Flame Wrasses

This Fourline Wrasse seems to be displaying aggression towards a few pairs of peaceful Hawaiian Fairy Flame Wrasses (C. jordani). Fourline Wrasses and others in their genus are aggressive toward slower moving or peaceful fish like fairy and flasher wrasses,leopard wrasses, and shy gobies. These are probably the least aggressive of their genus, but still need to be kept with fish that are larger and will not take their bossiness. They can do well in a reef tank as they will get rid of pyramidellid snails and flatworms, but they will attack ornamental shrimp. An interesting behavior is that they spin a cocoon at night within the rock work to sleep in.

  • Kingdom: Animalia
  • Phylum: Chordata
  • Class: Actinopterygii
  • Order: Perciformes
  • Family: Labridae
  • Genus: Pseudocheilinus
  • Species: tetrataenia
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Habitat: Natural geographic location:

The Four Line Wrasse is found in the tropical North and South Pacific; from Indonesia to Australia, Japan to Hawaii, the Marshall Islands and adjoining areas. They inhabit seaward reefs at depths of 20 feet to 145 feet (6 – 44 meters), dwelling close to the bottom among corals and rubble.


These fish are not listed on the IUCN Red List.


The Four Line Wrasse is a small beautifully colored fish. The body is dark blue with four orange lines outlined in black running horizontally across the upper part, and the eyes are red. The white lines through the red eye is similar to that of the Six Line Wrasse, but with four lines instead of six and a white chin you will quickly be able to differentiate the two. They are slightly smaller as well.

Length/Diameter of fish:

Four Line Wrasse adults will reach only 2.9 inches (7.3 cm).

Maintenance difficulty:

Being hardy and disease resistant, these fish are easy to maintain once they are established in the aquarium. They are poor shippers however, so make sure the individual you choose is eating and active.


The Four Line Wrasses are carnivores, provide a diet rich in all kinds of protein foods, formulas and flakes with an emphasis on small crustaceans. They are very active and need to be fed twice a day at least if not more. As with other lined wrasses they benefit from productive live rock. Picking on the rock is a particular love of theirs and they will eat the copepods, amphipods, and other micro fauna it provides.
In the wild they feed on many small organisms such as various crustaceans, molluscs, all kinds of worms, and fish eggs. In one article it was noted that during autopsy of 3 different four lines, one had remains of pistol shrimp, one had crab and a third only shrimp and gastropod larvae.


These fish are generally very easy to care for and are hardy. Provide basic marine aquarium care with a 20% water change monthly or 10% twice a month.
For more information see, Marine Aquarium Basics: Maintenance

Aquarium Parameters:

This timid fish needs to have plenty of good quality live rock with holes for hiding to feel comfortable especially in a smaller aquarium.
Minimum Tank Length/Size:
A minimum 20 gallon (75.7 liters) aquarium.,
Light: Recommended light levels
Prefers sunlight to moderate light. They don’t mind the bright light that most coral reef owners have due to their shallow water preferences.
No special requirements. Normal temperatures for marine fish is between 74° and 79° Fahrenheit.
Water Movement: Weak, Moderate, Strong
No special requirements.
Water Region: Top, Middle, Bottom
In the wild they are not found far from the bottom, in fact no more than a foot above the substrate. They will spend time in the bottom of the aquarium, but usually spending most of the time in the rockwork.

Social Behaviors:

The Four Lined Wrasse should be kept singly as they do not co-habitat well with other lined wrasses. They are basically reef safe with more semi-aggressive fish such as tangs, angels, and butterflies. They will not harm corals or coral anemones. They can also be kept in a non-reef setting with goatfish, puffers, and squirrelfish.
Do not keep with invertebrates such as small shrimp, or fish that are smaller than they are as they will become a quick meal. They have been known to go after small snails as well. It is feasible to keep the lined wrasses with larger crustacea however, as they reportedly are more amiable towards larger cleaner, marble and coral shrimp. Shy fish such as firefish, gobies, grammas, fairy wrasses, flasher wrasses, leopard wrasses, and others will be pestered to death. The mandarins may or may not be picked on, but most likely will be. They will also out compete the mandarins and other fish for food. Slow-moving feeders such as pipefish and seahorses will starve in their presence. Predators such as groupers, lionfish, and scorpion fish will eat the lined wrasses in a heartbeat.

Sex: Sexual differences:

It seems there is a direct correlation between size and sex for the Four Line Wrasse. The males are generally the largest, with females coming in second and immature fish being the smallest.
The males will show off a more intense coloring during mating.


Has not been bred in captivity.


The Four Line Wrasse, generally imported from Hawaii, is available most of the year. Usually it can be acquired by request from your pet store or found on the internet.