Lyretail Anthias Care Guide: The Ultimate Reef Schooling Fish

Species Overview#

The Lyretail Anthias (Pseudanthias squamipinnis) is the fish that turns a competent reef tank into something cinematic. Drop a harem of six into a 90-gallon mixed reef and the entire room reorganizes around them — orange females cruising the upper third of the water column, a single purple-red male flaring at the edges, the whole group reading currents and light the way a flock of starlings reads wind. They are the closest thing the reef hobby has to a guarantee that something interesting is always happening on the glass.

They are also the species most likely to be sold dead within 30 days of purchase by hobbyists who didn't understand what they were committing to. Anthias are not difficult fish in the technical sense — water parameters are standard, disease pressure is manageable, and they coexist with almost everything you'd want in a reef. The trap is metabolic. A Lyretail Anthias eats six to eight times per day in the wild, picking zooplankton out of the water column above the reef slope. In a home aquarium fed twice daily, they slowly starve while looking healthy, until one morning a female is dead on the sandbed for no apparent reason. The "no apparent reason" was three months of mild caloric deficit.

This guide treats that metabolic reality as the central fact of Anthias keeping. Get the feeding right and the rest of the husbandry — tank size, flow, harem ratios, quarantine — falls into place around it.

Adult size

5 in (12.5 cm) male, 3.5 in female

Lifespan

5-7 years

Min tank

75 gallons

Temperament

Peaceful (intra-species hierarchy)

Difficulty

Intermediate

Diet

Carnivore (zooplanktivore)

Reef safe

Yes, 100%

Sexual Dimorphism: Identifying Orange Females vs. Purple/Red Males#

Lyretail Anthias are one of the easier marine species to sex visually, which is fortunate because correct sex ratios are non-negotiable for long-term success. Females are a uniform tangerine to peach orange, slightly smaller, with relatively short fins and a single dark eye-line stripe running back from the upper jaw. Males are noticeably larger, deeper-bodied, and shift toward magenta, fuchsia, or red-violet depending on lineage and lighting. The defining male feature is the elongated third dorsal spine — a flag-like extension that they raise during courtship and territorial displays — and the deeply forked, lyre-shaped tail that gives the species its common name.

The species is a protogynous hermaphrodite, meaning every individual hatches female and the dominant fish in a group converts to male if no male is present or if the existing male dies. The transition takes roughly two to four weeks and is irreversible. You'll see the dominant female darken first around the dorsal fin, then develop the magenta wash across the flanks, then finally elongate the third dorsal spine. By the time the conversion is complete, she is functionally and behaviorally male.

Natural Habitat: The Coral Slopes of the Indo-Pacific#

Wild Lyretail Anthias inhabit the seaward faces of coral reefs across the Indo-Pacific, from the Red Sea and East African coast through the Maldives, Indonesia, Philippines, and out to Fiji and the Great Barrier Reef. They occupy the top 30 meters of the water column above outer reef slopes, drop-offs, and channel walls — anywhere current sweeps zooplankton up the reef face into a feedable cloud above the corals.

This is the single most important biogeographic detail for keepers. Anthias evolved in moving water. They feed in moving water. They breed in moving water. A reef tank with sluggish, stagnant zones simulates the wrong half of their habitat — the corals get the right environment, the Anthias get the wrong one. Plan for high turnover (15-20x display volume per hour) and you've solved a problem most keepers don't realize they have until their fish stop eating.

Lifespan and Maximum Size#

Captive Lyretail Anthias reach about 5 inches for males and 3 to 3.5 inches for females. Lifespan in a properly fed harem runs 5 to 7 years; underfed specimens rarely make it past 18 months. Wild fish are reported to live 8 to 10 years, but those numbers reflect a continuous food supply that home aquariums struggle to match without automation.

Water Parameters & Tank Requirements#

Lyretail Anthias don't tolerate the parameter swings that more forgiving species shrug off. They want the same stable, reef-quality water that your corals want — the species effectively works as a canary for SPS-grade husbandry. If your tank can keep an Acropora frag colored up, it can keep Anthias.

Minimum Tank Size: Why 75+ Gallons is Essential for Swimming Space#

The published minimum for a Lyretail Anthias harem is 75 gallons, and that number is honest — not the inflated "minimum" some species get saddled with. A six-foot 75-gallon tank gives a harem of one male and four females the horizontal swimming length they need to hold position at different points in the current without crowding the dominant male's territory.

A 90 or 125 is better, and a 180 is where Anthias start to look like the reef-flat schools you see in Red Sea diving footage. Vertical height matters less than horizontal length — Anthias hover and hold rather than dart up and down, so a six-foot footprint trumps a tall, narrow column every time. If you're planning the build from scratch, see our aquarium dimensions guide for the actual swimming-length differences across common reef sizes.

Flow and Oxygenation: Mimicking High-Energy Reef Slopes#

Aim for 15-20x display turnover from a combination of return pump and powerheads, with at least one gyre-style flow source creating laminar movement across the upper third of the tank where Anthias spend their time. Surface agitation matters as much as raw flow — Anthias have high oxygen demands and are among the first fish to show distress (gasping, surface-hugging) when dissolved oxygen drops at night.

A protein skimmer rated for double your tank volume helps both with O2 saturation and with handling the additional bioload that frequent feedings create. If you're running a covered tank, ensure adequate gas exchange through mesh tops or active gas exchange via a sump.

Specific Parameters: Temp, pH, and Specific Gravity#

Lyretail Anthias prefer the cooler end of the tropical range — 75°F is ideal, 78°F is the practical ceiling, and anything above 80°F sustained will accelerate metabolism past what your feeding schedule can support. Cooler tanks also hold more dissolved oxygen, which compounds in your favor.

pH should sit between 8.1 and 8.4, with daily swing under 0.2. Specific gravity of 1.024-1.025 mimics natural Indo-Pacific reef salinity. The species does not tolerate hyposalinity treatment well, which complicates ich treatment options — make quarantine protocols your first line of disease defense rather than relying on therapeutic salinity drops.

Diet & Feeding#

This is where Anthias keeping succeeds or fails. Read this section twice.

High Metabolism: The Necessity of 3+ Feedings Per Day#

A Lyretail Anthias in the wild eats more or less continuously during daylight, picking individual zooplankters from the water column. Estimates from reef studies put intake at 6-8 discrete feeding bouts per day, totaling perhaps 5-7% of body weight in food. A captive Anthias fed twice a day on flakes is operating at maybe 30% of natural caloric intake, and the deficit shows as gradual hollowing of the belly behind the pelvic fins, then darkening of color, then sudden death.

The realistic minimum schedule is three feedings per day — morning, midday, evening. Five feedings is closer to ideal. This is the single hardest constraint of the species and the reason most Anthias don't survive their first year.

Best Foods: Mysis, Calanus, and Vitamin-Enriched Brine Shrimp#

The dietary backbone for healthy Anthias is frozen Mysis shrimp and frozen Calanus copepods, both of which closely match the size and nutritional profile of natural prey. PE Mysis (Piscine Energetics) is the gold-standard product — larger, fattier, and cleaner than competing brands. Rotate in vitamin-enriched brine shrimp, oyster eggs, and Cyclop-eeze for variety.

Soak frozen foods in a vitamin supplement (Selcon or Vita-Chem) two to three times per week. The added HUFAs and vitamin C dramatically improve color retention and immune function in a species that's prone to stress-induced infections.

Avoid relying on freeze-dried foods or large pellets as primary diet items. Anthias have small mouths and digestive systems calibrated for small, soft, lipid-rich prey. Big pellets pass through partially digested.

Training to Accept High-Quality Pellets and Flakes#

Once your harem is established and feeding aggressively on frozen, start mixing in small high-quality pellets — Hikari Marine S, Reef Nutrition TDO Chroma Boost, or New Life Spectrum Marine Pellet. The training method is simple: introduce pellets at the same time as a frozen feeding so the Anthias hit them in the feeding frenzy. Within a week or two most fish will accept pellets eagerly, which lets you use the auto-feeder for the midday slot without sacrificing nutrition.

Tank Mates & Compatibility#

The Harem Dynamic: One Male to Multiple Females#

Lyretail Anthias are obligate group fish with a strict social structure. The functional minimum is a harem of one male and four females in a 75-gallon tank; six to eight females per male is better in larger systems. A single Anthias kept alone will pace the glass, refuse food, and decline within weeks. Two females without a male will fight until one converts, which is fine; two males in anything under 250 gallons will fight until one is dead.

When buying, source the entire harem from the same supplier on the same shipment if possible. Adding fish to an established harem weeks later triggers aggression as the existing male defends his group from the newcomer. If you must add fish later, redecorate the rockwork the night before introduction to disrupt established territory lines, and add at least two new females simultaneously to dilute aggression.

Reef Safety: Interaction with Corals and Invertebrates#

Lyretail Anthias are 100% reef safe in the strict sense — they do not nip at hard corals, soft corals, polyps, or ornamental invertebrates. They ignore cleaner shrimp, peppermint shrimp, tridacnid clams, anemones, and feather dusters. Their constant swimming above the rockwork actually improves coral health by sweeping detritus and improving micro-circulation around colonies.

The one minor caveat is feeding competition with corals. Anthias are voracious zooplankton predators, and in a tank with NPS corals like Tubastrea or Dendronephthya, the Anthias will outcompete the corals for any free-swimming food added. Target-feed your NPS corals after lights-out when Anthias are settled.

Suitable Neighbors: Blennies, Tangs, and Peaceful Wrasses#

The best Anthias tankmates are species that occupy different parts of the tank and have different feeding habits. Peaceful tangs like the yellow tang, tomini tang, or kole tang graze algae on the rockwork while Anthias feed in the open water — zero overlap.

Bicolor blennies, tailspot blennies, and lawnmower blennies take the bottom-rock niche without competing for food. Peaceful wrasses like six-line wrasse, melanurus wrasse, or yellow coris wrasse work well; avoid hyper-aggressive wrasses that may bully Anthias during settling. Banggai cardinalfish, pajama cardinalfish, and royal grammas are also reliable.

Avoid: large angelfish that may compete for water-column real estate, aggressive dottybacks in undersized tanks, triggerfish, and most damselfish other than blue-green chromis. Any fish with a "type A" personality will dominate feeding events and starve your Anthias by proxy.

Common Health Issues#

Uronema marinum: A Common Threat to New Anthias#

Uronema marinum is a parasitic ciliate that targets stressed, immunocompromised fish — and Anthias straight from the importer are the textbook case. Symptoms include bloody patches or open ulcers on the flanks, rapid breathing, and isolation from the harem. Mortality is high once symptoms appear, sometimes within 48 hours.

Prevention is the only reliable approach. Quarantine every new Anthias for a minimum of four weeks in a dedicated QT, ideally with a prophylactic course of metronidazole-soaked food and observation for ulcer development. Stress-management during transit and acclimation matters as much as medication — a fish that arrives well-fed and unstressed rarely contracts Uronema.

Decompression Issues and Swim Bladder Disorders#

Wild-caught Anthias are pulled from depths of 30-100 feet, and improper decompression during collection causes swim bladder injuries that present as positive buoyancy (the fish floats and can't dive) or, less commonly, negative buoyancy. Reputable importers and quality LFS holding tanks should rest fish for several days post-arrival to allow gas equilibration.

If you receive a Lyretail Anthias with swim bladder issues, mild cases often resolve over 7-14 days in a calm, low-flow QT. Severe cases — fish floating at the surface, unable to descend at all — usually don't recover and indicate cyanide collection or improper handling.

Stress-Induced Bacterial Infections During Acclimation#

The first 14 days post-introduction are the highest-risk window. Watch for clamped fins, color fading, gill flaring, and any white patches or fin erosion. Treat early with broad-spectrum antibiotics (Furan-2 or kanamycin) in QT if symptoms appear; a minor infection caught at day three is curable, the same infection at day ten is often fatal.

For broader marine quarantine protocol — including tank setup, copper dosing, and observation timeline — most experienced reefers run a 76-day QT cycle that catches both Cryptocaryon irritans (marine ich) and brooklynella before fish enter the display.

Where to Buy & What to Look For#

Lyretail Anthias come from the Red Sea, Maldives, Sri Lanka, and the Philippines/Indonesia. Source matters enormously: Red Sea and Maldivian fish are net-caught, well-acclimated, and command premium prices but justify them with survival rates north of 90%. Philippine and Indonesian imports are cheaper but carry historical concerns about cyanide collection that have improved but not disappeared.

Selecting Active Feeders at Your Local Fish Store (LFS)#

This is where the species' unique angle lives. Before you commit to buying a Lyretail Anthias — or, ideally, a harem — run the following inspection at the store. Treat any "no" as a deal-breaker, not a compromise.

Signs of Cyanide Fishing vs. Sustainably Caught Specimens#

Cyanide-collected fish often look fine for the first week or two, then crash inexplicably. Warning signs include: lethargy combined with normal appearance on day one (the fish swims poorly but isn't visually injured), unexplained bleeding from gills under stress, and a tendency to "give up" — fish that refuse food after a few days for no obvious environmental reason.

Net-caught Indonesian and Philippine fish are increasingly available — ask your supplier or LFS specifically about source country and collection method. Red Sea, Maldivian, and Vanuatu sources are essentially zero-risk for cyanide. Pay the premium; the survival math justifies it.

For broader context on building the system that will house your Anthias, see our saltwater aquarium guide and the larger saltwater fish overview.

Quick-Reference Cheat Sheet#

A correctly stocked, properly fed harem of Lyretail Anthias is one of the most rewarding sights in the marine hobby — color, motion, and genuine social complexity packed into a fish you can actually keep in a home-sized reef. Get the feeding schedule right, source from a reputable LFS that demonstrates active feeding, and quarantine without compromise. Do those three things and a good Anthias harem will outlive most of your other livestock.