Ctenochaetus tominiensis (Tomini Tang / Tomini Bristletooth Tang)
• Small fish safe: ✅ Yes
• Small invert safe: ✅ Yes
• Coral safe: ✅ Yes
• Minimum tank size: 250L+
• Adult size: ~15 cm
• Diet: Herbivorous (marine algae, seaweed, spirulina-based flakes/pellets, occasional meaty foods)
• Be aware of: Generally peaceful but may show territorial behaviour towards other tangs, especially bristletooth species. Requires a diet rich in marine algae to prevent nutritional deficiencies.
Tomini Tang (Ctenochaetus tominiensis) – A Hardy and Algae-Grazing Reef Fish
The Tomini Tang, also known as the Tomini Bristletooth Tang, is a small but highly efficient algae grazer from the Ctenochaetus genus, which includes the bristletooth tangs. These fish are excellent for controlling algae growth in reef tanks, making them a popular choice for marine aquarists. Their compact size, adaptability, and peaceful nature make them an ideal tang species for mid-sized reef aquariums.
Appearance and Coloration
Tomini Tangs have a subtle yet striking appearance. Their body is typically brown to olive in colour, with a slightly lighter belly. The fins, however, offer a beautiful contrast:
• Dorsal and caudal fins often have a bright yellow hue, especially in juveniles.
• Pectoral fins are typically orange or reddish, adding to their unique colour pattern.
• As they mature, their body may develop a deeper bronze or grey tone.
Unlike many other tang species, Tomini Tangs lack dramatic colour shifts between juvenile and adult stages, but their fin highlights remain vibrant throughout their life.
Natural Habitat and Behaviour
Tomini Tangs are native to the Indo-Pacific region, commonly found in coral reefs, lagoons, and reef slopes at depths ranging from 5 to 40 metres. They are active grazers, feeding on algae-covered rocks and sandy substrates.
In the aquarium, they spend most of their time:
• Grazing on algae growing on rocks and tank surfaces.
• Exploring rock crevices for food.
• Swimming in open water, though they prefer areas with plenty of hiding spaces.
Unlike some of the larger tang species, Tomini Tangs are not highly aggressive but can be territorial towards other bristletooth tangs. They generally coexist well with a wide range of reef-safe fish.
Tank Requirements and Water Parameters
The Tomini Tang is one of the smallest tang species, making it suitable for medium-sized marine aquariums. However, they still require ample swimming space and rockwork for grazing and shelter.
• Minimum tank size: 250L+ (larger preferred for long-term care)
• Temperature: 23–26°C
• pH: 8.1–8.4
• Salinity: 1.020–1.025
• Water movement: Moderate to strong
• Filtration: High-capacity filtration and protein skimming recommended due to their constant grazing behaviour
Because they are active algae eaters, having live rock with natural algae growth can help replicate their natural diet and environment.
Diet and Feeding
Tomini Tangs are herbivores, specifically detritivores that use their specialized bristle-like teeth to scrape algae off surfaces. Their diet should be rich in marine algae and vegetable matter, with occasional protein supplementation.
Recommended foods include:
• Dried seaweed (Nori) – Essential for digestive health
• Spirulina-based flakes and pellets – Helps maintain their colour and vitality
• Fresh macroalgae – Such as chaetomorpha or gracilaria
• Occasional meaty foods – Enriched mysis shrimp, brine shrimp (as a supplement only)
They should be fed multiple times per day, as they naturally graze throughout the day in the wild. A lack of algae in their diet can lead to nutritional deficiencies and stress.
Compatibility and Tank Mates
Tomini Tangs are one of the more peaceful tang species, making them an excellent choice for community and reef tanks. However, they may become territorial towards other bristletooth tangs or similar herbivorous fish.
Good tank mates include:
✔ Clownfish
✔ Gobies and blennies
✔ Peaceful wrasses
✔ Angelfish (dwarf and larger species)
✔ Other small to medium-sized reef-safe fish
Avoid housing with:
❌ Other bristletooth tangs (unless in a large system)
❌ Very aggressive tang species (e.g., Sohal Tang, Clown Tang)
❌ Slow-moving or timid fish that may struggle to compete for food
Health and Disease Considerations
Tomini Tangs are relatively hardy, but they can still be affected by common marine fish diseases, such as:
• Marine ich (Cryptocaryon irritans) – Often caused by stress or poor water conditions. Quarantining new fish before introducing them into the main tank is recommended.
• Head and Lateral Line Erosion (HLLE) – Often linked to poor diet, lack of algae, or water quality issues.
• Nutritional deficiencies – If not provided with enough marine algae, they may become weak or develop digestive problems.
Maintaining stable water parameters, a varied diet, and stress-free conditions will help keep them healthy.
Lifespan and Long-Term Care
With proper care, Tomini Tangs can live up to 10 years or more in captivity. They are one of the best tang species for home aquariums due to their manageable size, peaceful nature, and algae-eating habits.
Why Choose a Tomini Tang?
✔ Great for mid-sized reef tanks – Requires less space than larger tangs.
✔ Excellent algae grazer – Helps control nuisance algae in the aquarium.
✔ Generally peaceful – Can coexist with a variety of tank mates.
✔ Hardy and adaptable – Easier to care for compared to larger, more aggressive tang species.