Spotted Parrotfish (Cetoscarus ocellatus)
• Small fish safe: ✅ Yes (primarily herbivorous; generally peaceful towards other fish)
• Small invert safe: ✅ Yes (feeds mainly on algae; poses minimal threat to invertebrates)
• Coral safe: ⚠️ With caution (may inadvertently damage corals while grazing on algae)
• Minimum tank size: 1,000 liters (265 gallons)
• Adult size: Up to 80 cm (31 inches)
• Diet: Herbivorous, feeding primarily on benthic algae
• Be aware of: Requires ample grazing areas; undergoes significant color changes throughout life stages; needs stable water conditions
Appearance and Coloration
The Spotted Parrotfish exhibits remarkable color variations across its life stages:
• Juveniles: Predominantly white with a broad orange band encircling the head, excluding the snout and chin. A distinctive black spot (ocellus) adorns the dorsal fin, and the tail features a prominent orange band.
• Initial Phase (Females): Display a dark purplish to reddish-brown head with fine black spots ventrally. The body showcases a broad, pale yellowish area below the dorsal fin, transitioning to a bluish-gray hue ventrally. Scales are edged and spotted with black.
• Terminal Phase (Males): Exhibit a vibrant green body with pink-rimmed scales. The head and anterior body are adorned with numerous small pink spots above an orange line that extends from the mouth to the anal fin.
These color transformations are indicative of the species’ complex life cycle and social structure.
Natural Habitat and Behavior
Cetoscarus ocellatus is widespread throughout the Indo-Pacific region, inhabiting seaward reefs and clear lagoons at depths ranging from 1 to 30 meters. Juveniles are typically solitary, residing in dense coral and algal habitats, while adults often form harems consisting of a dominant male and multiple females. Males are territorial and play a crucial role in maintaining social hierarchies within these groups.
Tank Requirements and Water Parameters
• Minimum Tank Size: 1,000 liters (265 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 abundant live rock to support natural grazing behaviors.
• Ensure stable rock structures to accommodate their burrowing and foraging activities.
• Maintain open swimming spaces to suit their active nature.
• Lighting: Moderate to high, promoting algal growth for grazing.
• Water Movement: Moderate, replicating natural reef environments.
Diet and Feeding
As herbivores, Spotted Parrotfish primarily consume benthic algae, playing a vital role in reef ecosystems by preventing algal overgrowth. In captivity, it’s essential to replicate their natural diet to maintain health and vibrant coloration.
• Natural Diet: Benthic algae scraped from coral and rocky substrates.
• Captive Diet:
• Offer a variety of marine algae, such as nori or seaweed sheets.
• Provide high-quality herbivore pellets or flakes enriched with spirulina.
• Supplement with fresh vegetables like blanched spinach or lettuce.
Feeding Frequency: Multiple small feedings throughout the day to mimic their constant grazing behavior.
Compatibility and Social Structure
• Temperament:
• Generally peaceful and can coexist with a variety of tank mates.
• Males may exhibit territorial behavior, especially during breeding seasons.
• Tank Mates:
• Compatible with other non-aggressive species such as tangs, wrasses, and dwarf angelfish.
• Avoid housing with overly aggressive species that may harass or outcompete them.
• Reef Compatibility: ⚠️ With caution—while they primarily feed on algae, their grazing may inadvertently damage delicate coral structures.
Important Considerations
• Sexual Dimorphism and Hermaphroditism: Spotted Parrotfish are protogynous hermaphrodites, starting life as females and potentially transitioning to males, accompanied by significant color changes.
• Contribution to Sand Production: Their feeding behavior involves scraping algae and ingesting calcareous material, which is later excreted as sand, contributing to reef sediment production.
• Active Lifestyle: Provide ample space and environmental enrichment to accommodate their need for constant grazing and exploration.