Eight Lined Wrasse (Pseudocheilinus Octotaenia) saltwater aquarium fish

Overview:

The Eight Lined Wrasse is a hardy, active marine fish that does best in a mature, stable reef or fish-only aquarium with plenty of live rock and open swimming space. Despite its small size, it is highly energetic and needs a tank with secure lid coverage, as it may jump when startled. Provide strong water quality, high oxygenation, and consistent reef-appropriate conditions: temperature 74–80°F, salinity 1.023–1.026, and low ammonia, nitrite, and nitrate. This species appreciates a sandbed and rockwork that offers crevices for shelter and sleeping. Because it is constantly moving and exploring, a cramped or sparse environment can lead to stress and aggression.

Diet and Feeding:

Eight Lined Wrasses are carnivorous and should be fed a varied, protein-rich diet. Offer frequent small meals rather than one large feeding, especially for younger or newly introduced fish. Suitable foods include enriched frozen mysis shrimp, chopped seafood, brine shrimp, copepods, and other finely sized meaty marine foods. High-quality pellets or small marine flakes may be accepted once the fish is settled, but meaty foods should remain the core of the diet. Feeding 2–3 times daily helps maintain good body condition and supports their high metabolism. To promote health and color, vary the diet and soak foods in vitamins or omega-3 supplements occasionally. Avoid overfeeding, since uneaten food can quickly degrade water quality.

Compatibility:

This wrasse is usually peaceful with non-aggressive tankmates but may become assertive toward similarly shaped or similarly sized wrasses, especially in smaller tanks. It is best kept with calm community reef fish such as gobies, blennies, clownfish, tangs, and other nonterritorial species. Avoid housing it with large predatory fish that may view it as prey, and avoid highly aggressive species that may outcompete or harass it. In mixed wrasse communities, careful planning is important because some wrasses can be territorial or incompatible. In a reef aquarium, it is generally considered coral-safe, but it may hunt very small ornamental crustaceans such as tiny shrimp or small worms, depending on the individual. Provide enough rockwork and visual barriers to reduce conflict and allow each fish to establish space.

Health and Quarantine:

Common health concerns include stress from poor water quality, starvation in new arrivals, parasite exposure, and injuries from jumping or aggression. Quarantine is strongly recommended for 2–4 weeks before adding the fish to the display tank. During quarantine, observe for rapid breathing, flashing, loss of appetite, torn fins, or spots that may indicate parasites. A refugium or established pod population can help support feeding if the fish is picky at first. Because wrasses are sensitive to unstable conditions, keep quarantine water clean and well-oxygenated and offer frequent small meals. Good husbandry, gradual acclimation, and a secure environment are the best preventive measures for long-term success.

mysis shrimp brine shrimp high-quality marine flakes/pellets
The Eight Lined Wrasse is a highly active, constant swimmer that uses the full water column and benefits from a spacious aquarium with abundant rockwork and hiding places for retreat and display. It is generally bold and semi-aggressive to aggressive, becoming notably territorial toward conspecifics and other similarly shaped or brightly colored wrasses. A minimum tank size of 75 gallons is recommended, with a layout that includes visual barriers and broken sight lines to reduce chasing and help disperse aggression. In mixed systems it can coexist with other robust, fast-moving tank mates, but it is only conditionally reef-safe because it may harass or consume small crustaceans and ornamental invertebrates. Its diet is carnivorous to omnivorous, centered on active hunting of small benthic prey such as worms, snails, crustaceans, and other meaty foods, supplemented by prepared marine fare. Strong water movement, secure rockwork, and ample open swimming space are key to keeping this species healthy and behaviorally stable.

FAQ

Frequently Asked Questions

About the Eight Lined Wrasse

  • How do I reliably tell an Eight Lined Wrasse (Pseudocheilinus octotaenia) apart from a Sixline Wrasse before buying?
    An Eight Lined Wrasse typically shows more numerous, finer horizontal stripes and a more elongated look than a Sixline. The body is usually orange-brown to reddish with thin pale/blue-green lines, and the tail often has a brighter, more contrasting pattern. The biggest practical difference for hobbyists is behavior: Eight Lines are usually calmer and less hyper-aggressive than Sixlines, but still can be territorial. Buy from a dealer that can confirm the scientific name, because many “striped wrasses” are mislabeled.
  • Will an Eight Lined Wrasse eat flatworms, pyramid snails, and other pests like a Sixline?
    Yes, they are opportunistic micro-predators and may pick at flatworms, small worms, tiny crustaceans, and nuisance pods, but they are not as consistently “pest-exterminator” famous as Sixlines. Individual appetite varies a lot. Some become excellent hunters; others mostly graze on tiny meaty foods and ignore pests once established. Don’t buy one solely as a guaranteed pest-control solution.
  • What tank size and aquascape is best for an Eight Lined Wrasse?
    A mature aquarium of at least 30 gallons is the practical minimum, with more space preferred if you want to keep it with peaceful tankmates. They do best in a tank with lots of rockwork, caves, ledges, and tight crevices for escape routes and sleeping spots. A secure lid is essential; Eight Lined Wrasses can launch themselves when startled, especially during acclimation or at night.
  • Can an Eight Lined Wrasse be kept with shrimp, snails, and small ornamental crustaceans?
    Caution is needed. They are more likely than many “reef-safe” fish to bother tiny shrimp, very small crabs, and ornamental crustaceans, especially if the fish is hungry or larger. Cleaner shrimp and larger peppermint shrimp may be left alone in some tanks, but small sexy shrimp, very small cleaners, and delicate crustaceans are at higher risk. Snails are usually less at risk, though very small ones can be picked at.
  • Why is my Eight Lined Wrasse hiding all day, and how do I get it to eat in a new aquarium?
    New Eight Lined Wrasses often stay hidden for days because they are wary, easily stressed, and strongly tied to rock shelter. This is normal. Feed small, frequent meals of finely chopped meaty foods, frozen mysis, brine enriched with vitamins, and high-quality pellets if accepted. Turn off strong flow briefly during feeding and make sure no aggressive tankmates are bullying it. If it refuses food for several days but is still active and breathing normally, keep conditions stable and give it time to settle in.