Description
Red Pencil Sea Urchin – Heterocentrotus mammillatus
Overview:
The Red Pencil Sea Urchin is a striking and unique urchin, instantly recognizable by its thick, bright red spines resembling pencils. More ornamental than functional, it adds a bold splash of color and texture to aquariums.
Origin:
Native to the Indo-Pacific, often found in rocky reef areas exposed to strong surge zones.
Feeding:
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Feeds on algae, biofilm, and detritus.
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Supplement diet with dried seaweed, algae wafers, or fresh macroalgae if natural algae growth is limited.
Tank Mates:
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Reef-safe, but its size and strength mean it can dislodge corals or rockwork.
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Avoid with predatory fish such as puffers and triggers.
Aggression Level:
Peaceful. Will not bother tank mates but may inadvertently shift décor while moving.
Experience Level:
Intermediate. Requires stable, well-established aquariums with ample algae and strong rockwork.
Water Parameters:
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Temperature: 72–78°F (22–26°C)
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pH: 8.1–8.4
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Salinity: 1.023–1.025
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Tank Size: 75+ gallons
Unique Features:
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Iconic thick red spines for a dramatic display.
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Long-lived and hardy in stable reef systems.
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Excellent at helping control algae, though slower than other urchins.
✨ The Red Pencil Sea Urchin is both a conversation piece and functional grazer, perfect for large, established reef tanks.
