Royal Urchin – Mespilia globulus

About this invertebrate

Royal Urchin – Mespilia globulus is a saltwater urchin (Mespilia globulus) commonly kept in reef aquariums as an algae grazer and rock-cleaning invertebrate. In practice, it uses its spines and mouthparts to browse on biofilm and algae that build up on live rock and surfaces, helping you maintain a tidier-looking tank when mature food sources are available. It’s typically most useful in established systems where natural grazing and stable conditions support long-term keeping.

Features:

• Algae and biofilm grazing helps keep live rock and hard surfaces cleaner between feedings
• A spiny, reef-invertebrate display animal that adds texture and movement to your aquascape
• Works best when introduced to an established aquarium with ongoing natural growth on rocks
• Provides steady “cleanup” activity, especially in tanks where nuisance algae and film are managed by multiple methods
• Generally considered compatible with many reef setups, but it is still a living grazer—ensure adequate food availability

Specifications:

• Scientific name: Mespilia globulus
• Care level (general guidance): Moderate; most successful in established tanks with consistent food/algae availability
• Diet (general guidance): Primarily algae/biofilm and other plant-based grazing foods
• Tank type: Saltwater aquarium (reef or fish-only systems with appropriate stability)
• Water temperature (general guidance): About 72–78°F (22–26°C)
• Salinity (general guidance): About 1.020–1.025 specific gravity
• pH (general guidance): About 8.1–8.4
• Water parameters (general guidance): Aim for stable, reef-like conditions; maintain calcium and alkalinity targets appropriate for your system