Description

Orange Spine Sea Urchin – Tripneustes gratilla

Overview:
The Orange Spine Sea Urchin, also called the Collector Urchin, is a medium-to-large echinoderm known for its short, dense spines tipped in bright orange. It’s highly effective at algae control and is widely used in reef tanks as part of a clean-up crew.

Origin:
Native to the Indo-Pacific, including the Philippines, Fiji, Hawaii, and the Great Barrier Reef, where it grazes on seagrass beds, rubble zones, and reef flats.

Feeding:

Primarily an herbivore, grazing on film algae, macroalgae, and coralline algae.
May accept dried seaweed (nori), spirulina, and sinking algae wafers when natural food is low.

Tank Mates:

Reef-safe, does not eat corals.
Avoid predatory species like triggerfish, puffers, and large wrasses, which may nip at or eat urchins.

Aggression Level:
Peaceful. Non-aggressive, though it may accidentally dislodge small frags or unsecured rockwork while grazing.

Experience Level:
Intermediate. Hardy but requires a mature tank with established algae growth. Needs careful acclimation to avoid stress from salinity or pH shifts.

Water Parameters:

Temperature: 74–80°F (23–27°C)
pH: 8.1–8.4
Salinity: 1.023–1.025
Tank Size: 50+ gallons

Unique Features:

Dense, short spines tipped with orange give it a striking appearance.
Like other collector urchins, it may carry shells, rubble, or algae on its back for camouflage.
Plays a key role as an algae controller in reef aquariums.

✨ The Orange Spine Sea Urchin is a vibrant, hardy algae grazer and an excellent addition to well-established reef tanks, provided the aquarium is large enough and rockwork is secure.