Radial Filefish

Acreichthys radiatus

Also known as Radial Leatherjacket, Monacanthus radiatus

SaltwaterFish

Radial Filefish (Acreichthys radiatus) — Georgina Jones · CC BY-SA 4.0

Care at a glance

Temperature: 72–79°F (22–26°C)
pH: 8.1–8.4
Adult size: 3 in (7.6 cm)
Minimum tank: 20 gal (76 L)
Temperament: Peaceful
Social behavior: Social
Tankmates: Tankmates with caution
Swim level: Middle
Difficulty: Medium
Breeding: Medium
Rarity: Rare
Reef safe: Reef safe with caution
Origin: Western Pacific, southern Japan to Indonesia and New Guinea
Family: Monacanthidae

Overview

A peaceful, slow-moving fish that wants gentle flow, plenty of cover and small meaty foods a few times a day. Some individuals do pick at Aiptasia like their better-known cousin, but it is not a dependable cure, and pulsing Xenia and fleshy polyps may get nipped instead.

In the wild

Lives on western Pacific reefs from southern Japan down to Indonesia and New Guinea, almost always tucked among soft corals such as Xenia. Its radiating stripes and habit of drifting nose-down make it hard to pick out of the polyps.

Good to know

It is a close relative of the aiptasia-eating filefish, Acreichthys tomentosus, but stays smaller, topping out under 8 cm. In the wild, soft coral polyps and tissue form a regular part of its diet, which is worth knowing before it goes in a tank full of prized corals.

Did you know

Radial filefish even sleep attached to their host coral, biting gently onto a polyp at night and hanging there like a drifting leaf, usually without doing the colony any harm.