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Matted Filefish
Filefish

Matted Filefish

Acreichthys tomentosus

Also sold as the Bristletail or Aiptasia-Eating Filefish — a small, slow, mottled green-to-brown fish that changes shade to match its surroundings and hovers among rock and macroalgae rather than swimming in the open. It is bought almost entirely for aiptasia control, and many individuals do clear a tank of them, but this is not guaranteed: some ignore aiptasia completely and instead learn to pick at zoanthids, soft corals, LPS flesh and clam mantles. Treat it as a fish that may cost you corals, not as a reliable pest-control tool — keeping it well fed reduces but does not remove the risk. Its slow, deliberate swimming also means it is easily out-competed at feeding time and should not be housed with fast or boisterous fish.

Temperament
Peaceful
Max size
4.7"
Min tank
30 gal
Reef-safe
Reef safe with caution
Diet
Omnivore
Zone
Mid-water, Rockwork, Bottom
Keep one or a bonded pair.
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Tankmates

How Matted Filefish gets on with the rest of the reef, checked pair by pair by the same engine as the live pre-flight.

Best kept apart

A real clash — aggression, predation or a same-genus fight.

Purple TangPurple Tang (aggressive) is much larger than the peaceful Matted Filefish and may harass it.Red Coris WrasseLarge wrasses are named as tankmates that intimidate the matted filefish into constant hiding and poor feeding. The red coris grows to over a foot, feeds aggressively and becomes the dominant fish in the tank.Picasso TriggerfishPicasso Triggerfish (aggressive) is much larger than the peaceful Matted Filefish and may harass it.Neon DottybackAggressive dottybacks are named as tankmates to use caution with for the matted filefish. Its slow, cautious feeding style means it loses every race to a bold dottyback and ends up hiding.Royal DottybackThe matted filefish is a slow, deliberate swimmer that hides and stops feeding when a pushy fish is around. Royal dottybacks harass shy species relentlessly, so the filefish never settles in to hunt aiptasia.Dragon WrasseDragon Wrasse has a big enough mouth to eat the much smaller Matted Filefish.Volitans LionfishVolitans Lionfish has a big enough mouth to eat the much smaller Matted Filefish.Snowflake MoraySnowflake Moray has a big enough mouth to eat the much smaller Matted Filefish.Zebra MorayZebra Moray has a big enough mouth to eat the much smaller Matted Filefish.Chainlink MorayChainlink Moray has a big enough mouth to eat the much smaller Matted Filefish.Golden Dwarf MorayGolden Dwarf Moray has a big enough mouth to eat the much smaller Matted Filefish.Rectangle TriggerfishRectangle Triggerfish (aggressive) is much larger than the peaceful Matted Filefish and may harass it.Clown TriggerfishClown Triggerfish (aggressive) is much larger than the peaceful Matted Filefish and may harass it.Miniata GrouperMiniata Grouper (aggressive) is much larger than the peaceful Matted Filefish and may harass it.Panther GrouperPanther Grouper (aggressive) is much larger than the peaceful Matted Filefish and may harass it.Six-Line SoapfishSix-Line Soapfish has a big enough mouth to eat the much smaller Matted Filefish.Painted FrogfishPainted Frogfish has a big enough mouth to eat the much smaller Matted Filefish.Tiger Pistol ShrimpMatted Filefish hunts ornamental shrimp — your Tiger Pistol Shrimp is on the menu.Dogface PufferDogface Puffer has a big enough mouth to eat the much smaller Matted Filefish.Porcupine PufferPorcupine Puffer has a big enough mouth to eat the much smaller Matted Filefish.

Keep an eye on these

Usually fine, but worth watching in a smaller tank.

Maroon ClownfishMatted Filefish and Maroon Clownfish both claim the same part of the tank and may squabble.Blue DamselMatted Filefish and Blue Damsel both claim the same part of the tank and may squabble.Yellowtail DamselMatted Filefish and Yellowtail Damsel both claim the same part of the tank and may squabble.Flame AngelfishMatted Filefish and Flame Angelfish both claim the same part of the tank and may squabble.Coral Beauty AngelfishMatted Filefish and Coral Beauty Angelfish both claim the same part of the tank and may squabble.Lemonpeel AngelfishMatted Filefish and Lemonpeel Angelfish both claim the same part of the tank and may squabble.Bicolor AngelfishMatted Filefish and Bicolor Angelfish both claim the same part of the tank and may squabble.Red Saddleback ClownfishMatted Filefish and Red Saddleback Clownfish both claim the same part of the tank and may squabble.Yellow TangMatted Filefish and Yellow Tang both claim the same part of the tank and may squabble.Red Sea ClownfishMatted Filefish and Red Sea Clownfish both claim the same part of the tank and may squabble.Sailfin TangSailfin Tang (semi-aggressive) is much larger than the peaceful Matted Filefish and may harass it.Powder Blue TangAggressive tangs are listed among the boisterous tankmates that make the matted filefish hide and feed badly. A powder blue's constant fast movement is exactly the kind of pressure this slow, wary fish avoids.Purple DottybackAggressive dottybacks are on the caution list for the matted filefish. A purple dottyback claiming the rockwork will keep this timid, deliberate fish hiding instead of grazing.Convict TangMatted Filefish and Convict Tang both claim the same part of the tank and may squabble.Clark's ClownfishMatted Filefish and Clark's Clownfish both claim the same part of the tank and may squabble.Tomato ClownfishMatted Filefish and Tomato Clownfish both claim the same part of the tank and may squabble.Canary BlennyMatted Filefish and Canary Blenny both claim the same part of the tank and may squabble.Forktail BlennyMatted Filefish and Forktail Blenny both claim the same part of the tank and may squabble.Emperor AngelfishEmperor Angelfish (semi-aggressive) is much larger than the peaceful Matted Filefish and may harass it.Achilles TangMatted Filefish and Achilles Tang both claim the same part of the tank and may squabble.