Scribbled Filefish

The Scribbled Filefish (Aluterus scriptus), also known as the Scrawled or Broomtail Filefish, has an elongated, laterally flattened body marked with blue lines and spots over an olive-brown to gray background. Darker markings and a long tail contribute to an outline very different from the smaller, compact filefish commonly sold for home aquariums.

This circumtropical species occurs around reefs and other coastal structure, feeding on algae, seagrass, and a range of attached animal foods. It moves deliberately through its environment, inspecting and browsing surfaces rather than pursuing prey with rapid swimming.

Adult size is the defining husbandry concern. Although many individuals are smaller, the species has been documented to 43.3 inches (110 cm). It is an expert-care choice for a genuinely large, permanent display, not a small aquarium fish that can be accommodated by simply removing a few pieces of rock later.

Quick Care Guide

Care Level: Expert
Minimum Tank Size: 500 Gallons
Adult Size: Up to 43.3 inches (110 cm)
Temperament: Peaceful
Diet: Omnivore
Reef Safe: No
Region: Circumtropical
Scientific Name: Aluterus scriptus

Tank Requirements

Provide a mature aquarium of at least 500 gallons for adult housing. Allow for an adult reaching 43.3 inches (110 cm), and consider the usable footprint rather than the gallon rating alone. The fish needs room to turn, reach shelter, and feed without repeated close encounters with tankmates.

Plan at least 500 gallons as an adult starting point, with substantially larger custom housing potentially necessary for a maximum-sized fish. Evaluate actual swimming length, turning width, and the space remaining after equipment and rockwork are installed.

Use broad, securely supported structures around extensive open water. Small caves, narrow channels, and crowded rock towers are inappropriate for an adult of this length. Permanent housing must be arranged before purchase rather than relying on an uncertain future upgrade.

Arrange stable rockwork with protected retreats and clear routes between them. Maintain access for inspecting the fish and removing food fragments. Support heavy structures securely and avoid sharp projections along frequently used swimming paths.

Provide good oxygenation and effective biological and mechanical filtration while retaining calm areas. Gentle to moderate, distributed circulation is preferable to directing a powerful jet through its only resting or feeding location.

Fit a secure cover and protect equipment intakes. Close gaps around plumbing and overflows. Establish a calm introduction routine and avoid repeatedly chasing the fish out of shelter to make it visible.

Diet and Feeding

This omnivore consumes substantial plant material as well as attached animal foods. Make marine algae-based preparations a meaningful part of the menu rather than offering only meaty foods because the fish has a strong feeding response.

Provide seaweed and balanced omnivore foods in accessible browsing areas, together with suitable small marine animal foods. Scale the total ration and maintenance capacity as the fish grows, but retain manageable food pieces for its relatively small mouth.

Rotate foods with appropriate size and texture. Practical options include:

• Mysis shrimp

• Enriched brine shrimp as part of a varied diet

• Finely chopped marine shrimp, clam, or mussel

• Small pieces of squid

• Quality frozen marine omnivore preparations

• Marine algae-based foods and accepted pellets

Offer small portions two or three times daily, adjusting the total amount to body condition and observed intake. Distribute food across more than one location if companions intercept it, and give a new arrival time to feed close to cover.

Watch for actual swallowing rather than assuming that movement toward food means a successful meal. A fish that repeatedly mouths and rejects food may still be underfed. Maintain accepted foods while introducing variety gradually.

Remove leftovers before they break down among the rocks. Mature grazing surfaces add opportunities to explore, but they do not replace a deliberate feeding routine or regular checks of body condition.

Temperament and Tankmates

This filefish is generally peaceful toward unrelated fish, but can become territorial toward its own kind or other filefish sharing the same shelter. Calm behavior does not make it immune to harassment or prevent occasional investigative nipping.

A dedicated display is the most practical way to manage its exceptional adult space and feeding needs. If companions are considered, choose calm fish whose own permanent housing requirements can also be met, and avoid forcing a very large filefish into a crowded predator community.

Avoid highly aggressive triggers, persistent fin nippers, and unusually competitive feeders. A fish that remains confined to one corner, misses meals, or hides continuously to avoid pursuit is not successfully coexisting simply because serious injuries are absent.

Keep one specimen in a typical aquarium. Multiple filefish can compete for the same feeding surfaces and retreats, and an untested pair should not be assumed compatible because the individuals are small or appear quiet.

Observe introductions and reassess behavior as the fish settles in. Separated feeding locations and visual barriers can reduce mild competition, but persistent chasing, fin damage, or exclusion from food requires separation.

Reef Compatibility

Not reef safe. Coral and invertebrate compatibility must be assessed separately from its temperament toward other fish.

Its natural diet includes organisms such as gorgonians, colonial anemones, and other attached reef animals. Corals and ornamental invertebrates should therefore be regarded as potential food rather than decorative companions.

A dedicated large fish-only system is the appropriate long-term plan. The combination of adult size and browsing behavior makes a conventional home reef aquarium unsuitable even if a juvenile appears manageable.

Plan the display around the animals that need protection before introducing the filefish. A brief period without visible damage is not evidence that feeding preferences will remain unchanged, and frequent meals cannot guarantee the safety of ornamental livestock.

Water Parameters

Temperature: 72–78°F
Specific Gravity: 1.024–1.026
pH: 8.1–8.4
Alkalinity: 8–12 dKH

Maintain stable, well-oxygenated marine water with an established biological filter. Ammonia and nitrite should remain undetectable, and routine testing should guide water changes and nutrient export.

Check salinity with a calibrated instrument, replace evaporated water with freshwater, and match replacement saltwater carefully. Avoid abrupt changes in temperature, salinity, or pH during maintenance or transfers.

Frequent small meals require reliable cleanup of uneaten food. Observe appetite, respiration, and body condition alongside test results; clear water alone does not demonstrate that the fish is receiving suitable care.

Common Considerations

• Permanent Large-Display Housing: A possible 43.3-inch adult requires exceptional swimming and turning room; 500 gallons is a starting point, not a guarantee of suitability.

• Adult Space: Allow for 43.3 inches (110 cm) and at least 500 gallons, with appropriate swimming and turning room.

• Feeding Verification: Confirm food is swallowed and monitor body condition, particularly during acclimation.

• Compatible Companions: Protect this deliberate feeder from repeated chasing, fin nipping, and competition at meals.

• Reef Risk: Corals and exposed invertebrates may be eaten or damaged; regular feeding does not guarantee their protection.

• Careful Handling: The dorsal spine and textured skin can snag in fine mesh. Use a suitable container for transfers when practical, avoid chasing, and never pull an entangled fish forcibly free.