Siamese Blenny

Aquarium Requirements

Minimum Tank Size: 75 litres (20 US gallons)

Temperature: 24–28 °C (75–82 °F)

pH: 8.1–8.4

Specific Gravity (Salinity): 1.020–1.025

Alkalinity: 8–12 dKH

Ammonia & Nitrite: 0 ppm

Nitrate:< 10 ppm

Aquascape:
Provide plenty of live rock with natural crevices and overhangs for perching and shelter. The Siamese Blenny enjoys both resting within rockwork and swimming freely in open water. Moderate water flow and stable, mature water conditions promote health and natural behaviour. A secure lid or mesh top is recommended, as blennies may jump if startled.

Diet and Feeding

The Siamese Blenny is omnivorous, feeding on a variety of small planktonic animals and benthic algae in the wild. In captivity, it accepts a broad range of prepared foods with ease.

Recommended Foods:

• Frozen mysis shrimp, enriched brine shrimp, and finely chopped seafood

• High-quality marine omnivore pellets or flakes

• Spirulina- or algae-based foods for balanced nutrition

• Occasional live or frozen copepods and small crustaceans

Feed 2–3 times daily in small portions. A varied diet rich in both meaty and plant-based foods helps maintain colour and vitality.

Temperament and Compatibility

The Siamese Blenny is peaceful and social, making it well-suited to community reef aquariums. It generally ignores other fish, relying on its bright warning colours and mild venom for self-defence rather than aggression.

Suitable Tankmates:

• Clownfish, gobies, firefish, cardinalfish, and small wrasses

• Peaceful invertebrates and reef-safe species

Avoid:

• Large or aggressive fish (dottybacks, triggers, groupers, large wrasses) that may harass or intimidate it

• Other Meiacanthus species in small tanks unless sufficient space and rockwork are provided for individual territories

Reef Compatibility

✅ Reef Safe

The Siamese Blenny poses no threat to corals, clams, or invertebrates, making it entirely reef safe. Its grazing and planktivorous feeding habits integrate well into reef ecosystems. Unlike many blennies, it rarely disturbs substrate or corals.

Additional Information

Maximum Size: 10–11 cm (4–4.5 inches)

Lifespan: 4–6 years in captivity

Difficulty Level: Easy (hardy and adaptable)

Natural Behaviour: Free-swimming, perching, curious, peaceful

Origin: Indo-Pacific – Indonesia, Philippines, Malaysia region

Colouration: Distinctive black-and-white horizontal stripes with a silver sheen; translucent fins; juveniles and adults share similar patterns

Venom: Mild and used defensively; harmless to humans under normal aquarium conditions

Summary

The Siamese Blenny (Meiacanthus smithi) is a hardy, peaceful, and visually striking species ideal for reef and community aquariums. Its clean, contrasting coloration, gentle temperament, and active swimming behaviour make it a standout addition. With stable water conditions, plentiful rockwork, and a varied omnivorous diet, this fang blenny thrives as a resilient and rewarding aquarium resident.