Aiptasia-Eating Filefish — Acreichthys tomentosus

Effective pest control with risks. Reef-safe with caution.

Quick facts

• Size: 7–9 cm

• Temperament: Generally peaceful; can nip

• Reef-safe: With caution (zoas, LPS, clams at risk)

• Minimum tank: 120+ l / 30+ gal

• Role: Potential Aiptasia predator

Aquarium

• Aquascape: Live rock with hiding spots and open water for cruising.

• Water: pH 8.1–8.4, salinity 1.025–1.026, temp 24–26 °C; NH3/NO2 0, NO3 <20 ppm.

• Flow: Low–moderate.

• Cover: Advisable; can jump when startled.

Diet

• Primary: Meaty marine foods. Train to accept frozen mysis, chopped shrimp/clam, quality marine pellets.

• Aiptasia: Often eats Aiptasia but not guaranteed; appetite can vary by individual.

• Schedule: Small feedings 1–2× daily to reduce coral nipping once pests are gone.

Behavior and compatibility

• Coral risk: May nip zoanthids, fleshy LPS, SPS polyps, anemones, feather dusters, and clam mantles.

• Tankmates: Peaceful community fish; avoid fin-nippers and large predators.

• Social: Keep singly; pairs only in large tanks and introduced together.

Acclimation and care

• Acclimate: 30–45 min drip; dim lights.

• Observation: Camouflages and may hide at first; feeding response is the best health indicator.

• After pest control: Be ready to rehome if coral nipping starts.

Buyer’s checklist

• Eating frozen or pellets at the store.

• Rounded belly, alert, no frayed mouth or pinched look.

• Accept that Aiptasia control is not guaranteed and coral nipping is possible.