Mimic Filefish

Mimic Filefish

The Mimic Filefish (Paraluteres prionurus), also called the blacksaddle or false puffer, is one of the reef's great impostors. It has evolved to closely mimic the saddled toby pufferfish (Canthigaster valentini) — a fish whose flesh is toxic and which predators avoid. By copying the puffer's colours and even its swimming style, the harmless filefish gains protection it doesn't possess itself. It is a charming, characterful fish whose biology is as interesting as its looks.

Despite the disguise, it is a filefish, with a filefish's varied appetite that warrants some caution in a reef.

Natural Habitat & Origin

Paraluteres prionurus is found across the Indo-Pacific, where it lives on coral reefs, often in pairs, drifting among coral and rock as it forages. Its resemblance to the toxic toby lets it move about more openly than most small fish.

In the aquarium it appreciates live rock with crevices for shelter and grazing, in a calm community where its measured behaviour is not disturbed.

Care Requirements

Maintain stable marine conditions: salinity around 1.024–1.026, pH 8.1–8.4, and a temperature of about 24–26°C (75–79°F). Reaching about 11 cm (4.3 inches), it suits a tank of around 115 litres (30 US gallons) or more with plenty of rockwork. It is a relatively hardy fish that adapts well given a peaceful environment and a varied diet.

Diet & Feeding

The Mimic Filefish is an omnivore, feeding on a mix of algae, small invertebrates and coral polyps in the wild. In the aquarium it accepts a varied diet of frozen mysis and brine shrimp, finely chopped seafood, marine preparations and foods with marine algae content. Feed several small meals a day; a well-fed fish is less likely to sample corals.

Behavior & Temperament

This is a peaceful, deliberate fish that mixes well in a calm community and is often kept as a pair. It rarely troubles other fish and spends its time drifting and foraging among the rockwork. Avoid aggressive or fast tankmates that will outcompete or stress it.

Tank Mates

Good companions are peaceful reef fish — clownfish, gobies, smaller wrasses, cardinalfish and similar. In a reef, treat it with caution: like other filefish it may nip coral polyps, clam mantles and some ornamental invertebrates, so it is safest in fish-only systems or reefs with hardy corals. Notably, it should not be confused with — or expected to behave like — the toxic puffer it imitates.

Breeding

Paraluteres prionurus forms pairs and is a substrate spawner, but rearing the larvae is rarely accomplished in the home aquarium, so trade specimens are wild-collected.

Common Health Issues

The Mimic Filefish is reasonably hardy but, like all marine fish, can be affected by marine ich (Cryptocaryon irritans) and marine velvet (Amyloodinium ocellatum), particularly when stressed. As a slow, deliberate feeder it can also lose condition if outcompeted, so ensure it gets enough food. Quarantine new arrivals, keep water quality stable, and provide a calm tank — do that, and this fascinating mimic is an engaging and rewarding fish.