The Orange-Spotted Spinefoot (Siganus guttatus), also known as the Goldlined Spinefoot or Golden Rabbitfish, is a marine species belonging to the family Siganidae. It is native to the eastern Indian Ocean and western Pacific Ocean, inhabiting turbid inshore reefs among mangroves and seagrass beds around river mouths.
Key Information
• Small fish safe: ⚠️ With caution (may exhibit territorial behavior)
• Small invertebrate safe: ✅ Yes (primarily herbivorous)
• Coral safe: ⚠️ With caution (may nip at soft and large polyp stony corals if underfed)
• Minimum tank size: 500 litres (130 gallons)
• Adult size: Up to 42 cm (16.5 inches)
• Diet: Herbivorous, feeding on benthic algae
• Be aware of: Venomous dorsal, anal, and pelvic fin spines; handle with care to avoid envenomation
Appearance and Colouration
The Orange-Spotted Spinefoot exhibits a distinctive appearance:
• Body: Oval-shaped and laterally compressed, with a base coloration ranging from bluish to brownish-grey.
• Markings: Covered with numerous orange or gold spots across the head, body, and fins. A notable large golden spot is present at the base of the last few dorsal fin rays near the caudal peduncle.
• Fins: Dorsal fin with 13 spines and 10 soft rays; anal fin with 7 spines and 9 soft rays.
Juveniles display fewer and larger spots compared to adults. When stressed or during nighttime, they can change coloration to darker patterns for camouflage.
Natural Habitat and Behaviour
In the wild, Siganus guttatus is found in shallow coastal waters, often among mangroves and seagrass beds. They tolerate or even prefer low salinities and are known to enter and leave rivers with the tide. Unlike other siganids, this species is reported to be active at night. They form schools throughout their lives, with adult groups typically comprising 10 to 15 individuals. Their diet primarily consists of benthic algae.
Tank Requirements and Water Parameters
• Minimum Tank Size: 500 litres (130 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 spots, along with open swimming areas.
• Lighting: Moderate to high, supporting algal growth for natural grazing.
• Water Movement: Moderate, replicating natural reef environments.
Ensure stable water conditions to promote optimal health.
Diet and Feeding
As herbivores, Orange-Spotted Spinefoots require a diet rich in plant matter:
• Primary Diet:
• Marine algae or algae sheets (e.g., nori)
• Blanched greens such as lettuce or spinach
• High-quality marine herbivore pellets or flakes
• Supplementary Foods:
• Occasional offerings of mysis or brine shrimp
• Feeding Frequency: Provide algae or algae sheets continuously for grazing; offer other foods 2–3 times daily, ensuring only what they can consume in a few minutes to prevent overfeeding.
Compatibility and Social Structure
• Temperament: Generally peaceful; may become territorial towards other rabbitfish species.
• Tank Mates: Compatible with a variety of peaceful to moderately aggressive species; caution advised when housing with other rabbitfish to prevent aggression.
Important Considerations
• Venomous Spines: Possess venomous dorsal, anal, and pelvic fin spines capable of inflicting painful wounds; exercise caution during tank maintenance and handling.
• Reef Compatibility: While generally reef-safe, underfed individuals may nip at certain soft and large polyp stony (LPS) corals; ensure adequate feeding to mitigate this risk.
• Dietary Needs: A diet rich in vegetable matter is essential; insufficient feeding may lead to undesirable behaviors, including coral nipping.
Summary
The Orange-Spotted Spinefoot (Siganus guttatus) is a vibrant and beneficial addition to large marine aquariums, particularly valued for its algae-grazing habits. Aquarists must exercise caution due to its venomous spines and ensure a diet rich in vegetable matter to maintain health and appropriate behavior. With proper care, this species can thrive and contribute positively to the aquarium ecosystem.