Matted Filefish

🟩 Matted Filefish Quick Stats

• Scientific Name: Acreichthys tomentosus

• Common Names: Matted Filefish, Bristletail Filefish, Aiptasia-Eating Filefish

• Adult Size: 3–4 inches (7.5–10 cm)

• Temperament: Peaceful to semi-aggressive (varies by individual)

• Lifespan: 3–5 years

• Tank Size: 30+ gallons

• Water Parameters:

  • Temperature: 72–78°F (22–26°C)

  • pH: 8.0–8.4

  • Salinity: 1.020–1.025 SG

  • Nitrates: <20 ppm

• Diet: Omnivore – meaty foods, sometimes picks at coral

• Difficulty: Moderate

🐡 Description

The Matted Filefish is a small, oddly shaped reef fish known for its camouflage ability and usefulness in pest control. Its mottled green and brown coloration helps it blend in with live rock and macroalgae. Most notably, this species is one of the few natural predators of Aiptasia anemones, making it popular among reef keepers struggling with pest infestations.

🧼 Care Guide

• Tank Setup: Provide plenty of live rock for grazing and hiding. A peaceful reef or fish-only tank works best.

• Behavior: Generally peaceful, but may nip at corals or sessile invertebrates—reef compatibility is hit or miss. Monitor closely.

• Feeding: Accepts a variety of frozen foods (mysis, brine, chopped seafood) and may take pellets over time. Needs frequent feeding.

• Aiptasia Control: Highly valued for this purpose, but not all individuals eat Aiptasia, and some may stop after acclimating to tank foods.

• Reef Safe? With caution – some individuals are completely reef safe, while others develop a taste for zoanthids, LPS, or softies.

• Breeding: No successful captive breeding; all are wild-caught. Sexing is difficult.