What Bartlett's Anthias Are and Why They're Hard to Keep

Bartlett's anthias are small, brilliantly colored reef fish native to the Indo-Pacific, prized by aquarists for their vibrant orange and purple markings and active schooling behavior. They are also among the most difficult anthias species to maintain in captivity, with high mortality rates even in experienced hands. Most die within weeks or months because they refuse to eat prepared foods, require constant feeding on live prey, and are extremely sensitive to water quality swings and tank stress.

If you are drawn to their appearance, you should know upfront that success requires a mature, well-established tank, live food cultures running continuously, and the willingness to spend significantly more on feeding than on the fish itself. Many aquarists who buy them without this setup lose them quickly and expensively. The species is not a beginner fish, and it is not a fish for anyone who travels or cannot maintain daily feeding schedules.

Key Takeaways

  • Bartlett's anthias refuse frozen and pellet foods almost universally and will starve rather than eat them, so you must culture live copepods, amphipods, or rotifers continuously.
  • They require tanks of at least 75 gallons with strong water flow, excellent filtration, and stable parameters—any ammonia or nitrite spike will kill them within hours.
  • Males are highly territorial and will fight each other; females can sometimes coexist in groups, but aggression is common and unpredictable.
  • Even in ideal conditions, captive-bred specimens have a survival rate far below other reef fish, and wild-caught individuals often die within days of arrival.
  • Feeding costs and the time required to maintain live food cultures often exceed the cost of the fish within the first month.

Tank Size, Flow, and Water Conditions

Bartlett's anthias need a minimum of 75 gallons, though 100 gallons or more is safer for a small group. They are active swimmers that dart constantly through the water column and require strong, turbulent flow—aim for 10 to 20 times the tank volume per hour. Poor flow leads to dead zones where uneaten food decays, spiking ammonia and nitrite, which these fish cannot tolerate.

Water parameters must remain stable: pH 8.1 to 8.3, salinity 1.023 to 1.025, and temperature 74 to 78 degrees Fahrenheit. Nitrate should stay below 20 ppm, ideally below 10 ppm. Any deviation causes stress, reduced feeding, and rapid decline. Frequent water changes—20 to 30 percent weekly—are standard practice. Protein skimmers must run continuously, and many keepers add refugiums or separate live rock chambers to maintain copepod populations and reduce nitrate buildup.

Live Food: The Central Challenge

Bartlett's anthias will not eat frozen mysis shrimp, frozen copepods, or any pellet food. They feed on tiny crustaceans and zooplankton in the wild and will only accept live prey in captivity. The most reliable foods are live copepods (particularly Tigriopus and Acartia species), live amphipods, and rotifers. Many keepers maintain two or three live cultures running at all times to ensure a constant supply.

Culturing live food requires space, attention, and cost. A basic copepod culture needs a 5 to 10-gallon container, lighting, aeration, and weekly feeding with phytoplankton or specialized culture media. A rotifer culture requires similar setup. You will spend $20 to $50 per month on starter cultures, phytoplankton, and media, plus the electricity to run them. Feeding the fish itself—siphoning live copepods into the tank twice daily—becomes a daily ritual. If cultures crash or you miss a few days, the fish starve.

Behavior and Compatibility

In the wild, Bartlett's anthias form loose aggregations, but in captivity the dynamics are unpredictable. Males are extremely territorial and will fight to the death if confined together. A single male can be kept alone or, rarely, with a group of females, but even females will sometimes attack each other without warning. Aggression often escalates suddenly after weeks of apparent peace.

They are also prey-driven and will eat small shrimp, gobies, and other fish small enough to fit in their mouths. They can coexist with larger fish and most corals, but they are nervous and easily stressed by tank mates that chase or harass them. Sudden changes in tank mates, even the addition of a single new fish, can trigger a feeding strike that lasts days.

Sourcing and Acclimation

Wild-caught Bartlett's anthias arrive stressed and often already injured or diseased. Mortality in the first week is common. Captive-bred specimens, available from a few specialized breeders, have better survival odds but are expensive—often $80 to $150 per fish—and still require the same live food setup. Neither source is a may provide of survival.

Acclimation must be slow and careful. Use a drip line over 2 to 3 hours, not a bucket float. Place the fish in a dark acclimation box or quarantine tank for the first 24 to 48 hours before introducing it to the main tank. Even with perfect acclimation, some fish refuse to feed and die within a week. Have live copepods in the tank and ready before the fish arrives.

Health Problems and Common Causes of Death

Starvation is the leading cause of death. Fish that refuse live food or cannot find it in the tank will waste away over 1 to 2 weeks. Ammonia and nitrite spikes from uneaten food or inadequate filtration kill them within hours. Parasites and bacterial infections are common in wild-caught fish and spread rapidly in stressed populations.

Secondary infections often follow stress or poor feeding. Ich (white spot disease) and velvet are frequent in newly arrived fish. Treating these with copper or other medications is risky because anthias are sensitive to many common treatments. Prevention through quarantine, stable water conditions, and low stress is far more effective than treatment.

Is Bartlett's Anthias Right for Your Tank?

Bartlett's anthias should only be considered by experienced reef keepers with established tanks, running live food cultures, and the time and money to maintain them. If you are new to reef keeping, have a tank under 100 gallons, or cannot commit to daily live feeding, choose a different anthias species or a different fish entirely. The financial and emotional cost of repeated failures is high.

If you do decide to keep them, start with a single female or captive-bred specimen, not a wild-caught male. Have your live food cultures established and thriving for at least two weeks before the fish arrives. Expect the first month to be a learning curve with a real risk of loss. Many aquarists who succeed with Bartlett's anthias say the effort is rewarding, but only because they went in with realistic expectations and proper preparation.

Frequently Asked Questions

Can I feed Bartlett's anthias frozen copepods or any prepared food?

No. They will starve rather than eat frozen or pellet foods. Live copepods, amphipods, or rotifers are the only foods they will consistently accept. Some keepers report occasional success with live brine shrimp, but this is unreliable and nutritionally incomplete.

How many can I keep in one tank?

A single male or a small group of females in a 100+ gallon tank with excellent flow and hiding spaces. Males will fight each other to the death. Females may coexist but often turn aggressive without warning. Most keepers keep just one.

What is the lifespan of a Bartlett's anthias in captivity?

If it survives the first month, it can live 3 to 5 years. Most die within weeks. Captive-bred fish have better odds than wild-caught, but even they have high early mortality. Longevity depends entirely on your ability to maintain stable conditions and continuous live feeding.

Can I keep Bartlett's anthias with corals?

Yes, they are generally reef-safe and will not eat or damage most corals. They may pick at small zoanthids or polyps if hungry, but they pose no threat to large corals or anemones.

Why do so many Bartlett's anthias die in the first week?

Stress from shipping, inability to find or accept live food in a new tank, and ammonia spikes from uneaten food are the main killers. Wild-caught fish are especially vulnerable. Slow acclimation, established live food cultures, and a mature tank with excellent filtration reduce but do not eliminate early mortality.