Blue-Spotted Spinefoot (Siganus corallinus)
The Blue-Spotted Spinefoot (Siganus corallinus), also known as the Coral Rabbitfish, is a vibrant and peaceful species native to the Indo-West Pacific. Its bright yellow body covered in blue spots makes it an eye-catching addition to marine aquariums. Like other rabbitfish, it plays an important role in controlling algae growth, but its venomous spinesrequire careful handling.
Key Information
• Small fish safe ✅ Yes (generally peaceful)
• Small invertebrate safe ✅ Yes (primarily herbivorous)
• Coral safe ⚠️ With caution (may nip at soft and large polyp stony corals if underfed)
• Minimum tank size 380 litres (100 gallons)
• Adult size Up to 35 cm (14 inches)
• Diet Herbivorous, feeding predominantly on benthic algae
• Be aware of Venomous dorsal, anal, and pelvic fin spines; handle with caution
Appearance and Colouration
The Blue-Spotted Spinefoot is easily recognisable due to its vibrant colouration and patterning:
• Body Colouration
The body is bright yellow to orange, covered in small iridescent blue spots across the head, body, and fins.
• Head Markings
A dark patch surrounds the eye, blending into the yellow body.
• Juvenile vs. Adult
Juveniles have thin vertical blue lines, which transform into spots as they mature.
Natural Habitat and Behaviour
In the wild, Siganus corallinus inhabits coral-rich lagoons and shallow reefs, at depths of 3 to 30 metres. Juveniles form schools among seagrass beds and coral formations, particularly Acropora corals, while adults are typically found in pairs.
• Habitat
Often seen grazing on benthic algae, helping to maintain a healthy reef ecosystem.
• Camouflage Ability
Can darken its colours when stressed or at night.
Tank Requirements and Water Parameters
• Minimum Tank Size 380 litres (100 gallons)
• Water Parameters
• Temperature 24°C – 28°C (75°F – 82°F)
• pH 8.1 – 8.4
• Specific Gravity 1.020 – 1.025
• Aquascaping
• Provide ample live rock for grazing and hiding.
• Allow open swimming areas to accommodate its active nature.
• Lighting Moderate to high to encourage algal growth for grazing.
• Water Movement Moderate, mimicking reef conditions.
Diet and Feeding
As herbivores, Blue-Spotted Spinefoots require a plant-based diet to stay healthy and reduce the risk of coral nipping.
• Primary Diet
• Marine macroalgae and algae sheets (e.g., nori).
• Blanched spinach, romaine lettuce, and seaweed.
• High-quality herbivore pellets and flakes.
• Supplementary Foods
• Occasional mysis shrimp or brine shrimp.
• Feeding Frequency
2–3 times per day, ensuring continuous access to algae for grazing.
Compatibility and Social Structure
• Temperament
• Peaceful, making it suitable for community aquariums.
• May become territorial with other rabbitfish species.
• Suitable Tank Mates
• Compatible with tangs, angelfish, clownfish, and wrasses.
• Avoid housing with aggressive species that may bully or stress it.
Important Considerations
• Venomous Spines
• The dorsal, anal, and pelvic spines contain venom that can cause painful stings.
• Always be aware of their location during tank maintenance.
• Reef Compatibility
• Mostly reef-safe, but may nip at corals if underfed.
• Algae Control Role
• Helps maintain low algae levels in large aquariums.
Summary
The Blue-Spotted Spinefoot (Siganus corallinus) is a striking, algae-grazing species that thrives in large, well-maintained marine aquariums. With proper diet and stable water conditions, it serves as both a beautiful and functional addition, helping to prevent algae overgrowth. However, its venomous spines and potential for coral nipping require careful management.