Squaretail Bristletooth Tang

Squaretail Bristletooth Tang (Ctenochaetus truncatus)

Appearance & Behavior

Fine spots and a squared tail distinguish this compact bristletooth. This active surgeonfish needs room to cruise between established grazing areas and sheltered resting places. Sale-size and juvenile designations do not reduce permanent adult housing requirements.

Quick Care Guide

• Care level: moderate; requires an established marine aquarium and sustained nutrition.
• Temperament: semi-aggressive, particularly toward similar surgeonfish.
• Adult size: approximately 6.5 inches.
• Minimum aquarium: 70 gallons, with a long, wide footprint and open swimming lanes.
• Diet: surface grazer; microalgae, detrital films, and suitable prepared foods.
• Reef compatibility: generally reef-safe; individual coral nipping is possible.
• Temperature: 72–78°F.
• Specific gravity: approximately 1.023–1.025; maintain stable salinity suited to all inhabitants.
• pH: 8.1–8.4.
• Alkalinity: 8–12 dKH; prioritize stability and the needs of the aquarium.

Aquarium Setup & Compatibility

Provide a mature, fully cycled aquarium with secure rockwork for grazing, spacious retreats, and broad swimming lanes. Length and turning space matter as much as nominal volume. Maintain effective filtration, vigorous oxygenation, varied circulation, and regular water changes. Provide calmer resting areas and use a secure lid.

Leave mature grazing surfaces available without packing the aquarium so densely that swimming space is lost.

Choose appropriately sized companions that neither bully the new tang nor become targets of territorial behavior. One tang is the safest starting point for most home setups. Mixing surgeonfish requires substantially more space, multiple feeding areas, careful introductions, and a practical separation plan. Different colors or genera do not guarantee compatibility.

Introduce less assertive fish first where practical and monitor chasing, feeding access, and injuries after every stocking change. Tangs have sharp tail-base defensive spines; use suitable transfer equipment and avoid handling the fish or cornering it with bare hands.

Reef & Invertebrate Compatibility

Most individuals coexist with corals and typical ornamental invertebrates, but occasional coral or clam-mantle picking can occur. Monitor tissue condition rather than assuming reef safety is absolute. Tiny animal life may be consumed during natural foraging, and large fish can disturb unsecured frags. Algae grazing does not replace aquarium maintenance or guarantee control of a particular nuisance algae.

Feeding

Offer mature surfaces with fine algal and detrital films alongside algae-containing marine preparations, suitable pellets, and finely sized frozen foods. Bristletooth mouthparts brush surfaces; they should not be expected to remove every type of long filamentous algae.

Provide small meals two or three times daily and regular opportunities to graze. Use multiple food locations if a dominant resident monopolizes the clip. Growing juveniles may need extra small feeding opportunities with appropriately sized particles. Established rockwork supplements the diet but must not be assumed to sustain the fish indefinitely.

Verify swallowing and monitor body fullness, especially behind the head. A thin fish that constantly searches surfaces may still be underfed. Vary the diet, remove uneaten seaweed and leftovers promptly, and maintain water quality rather than compensating with excessive portions.

Introduction & Long-Term Care

Quarantine new arrivals when possible and establish reliable feeding before introduction to the display. Tangs are susceptible to external parasites, including marine ich, and a fish eating well is not proof that it is disease-free. Captive-bred or tank-raised designations do not eliminate the need for appropriate observation and disease prevention.

Acclimate to temperature and salinity, reduce lighting during introduction, and provide access to shelter. Monitor breathing, skin, fins, body condition, and social interactions daily. Seek experienced aquatic-veterinary guidance for persistent rapid breathing, lesions, weight loss, or food refusal. Maintain stable conditions and arrange dependable grazing and feeding during absences.