Sixline Wrasse
Pseudocheilinus hexataenia
Active, jewel-toned hunter of reef pestsBeginner
- Lifespan
- 4-7 years
- Size
- 7-8cm (3in)
- Social needs
- One per tank in most systems
- Time
- Low
- Cost
- Medium
- Diet
- Carnivore, micro-invertebrates
Overview
What is this animal?
- The Sixline Wrasse is a small, fast, jewel-toned fish striped orange and blue, popular for its hardiness and appetite for reef pests.
- It is constantly active, darting through rockwork in search of food.
- It is reef-safe and helps control pyramidellid snails and some flatworms.
- Easy to keep, it suits beginners, though its bold temperament can grow more aggressive as it matures.
Temperament
- Active and bold, it becomes increasingly territorial and aggressive with age, sometimes harassing newly added or timid fish.
- Add it last to a community so existing fish are established, and keep only one per tank.
- Reef-safe with corals and most invertebrates, it leaves desirable inverts alone while hunting pests.
- Its assertive nature means careful tankmate selection in smaller or peaceful systems.
A good fit for
- Beginners wanting a hardy, active fish
- Reef tanks needing pest control
- Mature tanks with healthy pod populations
- Keepers wanting colour and movement
Common mistakes to avoid
- Grows territorial and aggressive with age
- Add last so it cannot dominate
- Known jumper; needs a secure lid
- May bully timid or newly added fish
Enclosure
Minimum 110 litres (29 US gallons)
Must be housed alone. One per tank in most systems
- House in an established reef of at least 110L (30 gallons) with abundant live rock full of crevices to hunt and shelter in.
- A mature tank with a good population of micro-invertebrates provides natural foraging.
- Keep temperature 24-27C (75-81F), salinity 1.024-1.026, pH 8.1-8.4, and ammonia and nitrite at zero.
- Plenty of rockwork lets this active fish exercise its natural hunting behaviour.
Supplies
Setup
- Tank, stand and sump
- Return pump and powerheads
- Protein skimmer
- Reef lighting
- Rock and sand
- Salt mix, refractometer and test kits
- Quarantine tank
Ongoing
- Frozen mysis shrimp
- Frozen enriched brine shrimp
- Marine flake or small pellet
- Copepod bottle for periodic top-ups
- Refugium media or a pod hotel (optional)
- Vitamin or HUFA soaking supplement
- Small thawing cup and strainer
Safe substrate: Aragonite sand · Dry or cured live rock · Bare bottom
Care routine
Daily
- Check salinity, temperature and flow
- Check the lid and sand bed
- Feed
- Head-count and look everyone over
- Top up evaporation with fresh water
Weekly
- Service the skimmer and filter socksevery 3 days
- Clean the glass
- Test the water
Monthly
- Water changeevery 2 weeks
- Calibrate the refractometer
- Check salt, RO/DI and reagents
Less often
- Deep-clean pumps and powerheadsevery 3 months
- Replace RO/DI filter mediaevery 6 months
Vet: Quarterly review with lid and sand-bed check — every 3 months
Top resources for more info
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Diet
- A carnivore that hunts copepods, amphipods, small worms, and other micro-invertebrates among the rocks.
- Supplement with frozen mysis and brine shrimp, marine flakes, and pellets once or twice daily.
- A mature tank with a healthy pod population supports natural grazing between feedings.
- It readily accepts prepared foods, making it simple to keep well-fed and active.
Health
- Hardy and disease-resistant, one of the more forgiving marine fish, though quarantine remains best practice.
- Stable water and a varied diet keep it healthy and well coloured.
- Watch for hiding, faded colour, or reduced appetite as signs of stress or poor conditions.
- It can also jump, so a secure lid prevents the most common cause of accidental loss.
Is your enclosure big enough?
Is this urgent?
In a reef, stability matters more than any single target number. A parameter moving fast does more damage than a parameter sitting slightly off.
Go now
Today
Quarantine every new animal, including corals and inverts. It is the single practice that separates a reef that lasts from a reef that restarts.
This is general guidance for a healthy adult, not a diagnosis. An exotics vet who knows your animal always overrides it — and the time to find one is before you need one.
What it really costs
Setup, monthly, first year and across a whole life, itemised and with the electricity worked out from the actual wattage. Published figures for the same animal disagree by a factor of four, so the calculator shows ranges rather than picking one.
Bedding and substrate
In a marine system the rock and the sand are life support, and how you start them decides the first six months.
Safe
With a caveat
Never
This is our general list for saltwater fish. We have not built one specific to Wrasses yet.
My kit says 0.25 ppm. Is that dangerous?
A liquid kit measures total ammonia, but only the un-ionised fraction is really toxic, and that fraction is governed by pH and temperature — each whole pH unit multiplies it roughly tenfold. So the same reading can be nearly harmless in one tank and lethal in another; this works out which one you are in.
Compare with other animals
The same axes for every animal, side by side — the way the guides are written makes that a fair comparison rather than two articles.
Other Saltwater Fish worth knowing
Same axes, same care guides — the honest way to compare them.
Browse all Saltwater Fish →
