Adding to a Brand-New Tank

Trochus Snails require algae and biofilm to graze. Sterile tanks may not provide enough food initially.

Starving Them in Ultra-Clean Systems

Low nutrient systems can remove natural algae sources, requiring supplemental feeding.

Not Securing Coral Frags

Decorator Urchins frequently carry loose objects on their body and may pick up unsecured coral frags, rubble, or decorations.

Why is my Decorator Urchin carrying shells, rubble, or coral frags?

This is completely normal behaviour. Decorator Urchins intentionally place shells, rubble, macroalgae, and other objects on their body as camouflage and protection from predators and bright light.

Will a Decorator Urchin pick up coral frags?

Yes. Unsecured coral frags are commonly carried around the aquarium by Decorator Urchins. This is one of the main reasons reef keepers should ensure frags are properly glued or secured.

Is the Decorator Urchin good for controlling hair algae?

Absolutely. Decorator Urchins are among the most effective algae grazers available and can consume significant amounts of hair algae, turf algae, and film algae in established reef aquariums.

Why has my Decorator Urchin stopped decorating itself?

Newly introduced specimens, recently stressed individuals, or urchins that lack suitable materials may temporarily stop carrying objects. Most healthy Decorator Urchins eventually resume this natural behaviour.

Will a Decorator Urchin eat coralline algae?

Yes. Like many sea urchins, Decorator Urchins commonly graze coralline algae along with nuisance algae. Hobbyists aiming to maximise coralline growth should consider this before adding one.

How do I know if my Decorator Urchin is healthy?

Healthy Decorator Urchins actively move around the aquarium, maintain strong attachment to surfaces, respond to touch, and display intact spines and tube feet.

Sold out

Aquamarine Aquaristic

Decorator Urchin (Tripneustes gratilla)

Name: Decorator Urchin (Tripneustes gratilla)
Brand: Aquamarine Aquaristic
SKU: 45858037432566
Price: 45.0 AUD
Availability: OutOfStock

$45.00 each

Out of stock

Decorator Urchin (Tripneustes gratilla) Description The Decorator Urchin is one of the most popular and entertaining sea urchins in the marine aquarium hobby. Famous for its habit of carrying shells,...

Read full description →

Arrive Alive guarantee Replacement or store credit

Door-to-door delivery Australia-wide options

Secure checkout

Description

Decorator Urchin (Tripneustes gratilla) Description

The Decorator Urchin is one of the most popular and entertaining sea urchins in the marine aquarium hobby. Famous for its habit of carrying shells, coral rubble, macroalgae, and other objects on its body, this species constantly decorates itself for camouflage and protection. In addition to its unique behaviour, the Decorator Urchin is an excellent algae grazer, helping to control nuisance algae and keep rockwork clean. Its relatively reef-safe nature and hardworking grazing habits make it a favourite among reef keepers looking for both functionality and personality in their clean-up crew.

Shipping To Tasmania	YES
Shipping To Western Australia	NO

Husbandry

Care guide

Care difficulty

BeginnerModerateExpert

Beginner

Temperament

SkittishPeacefulSemi-agg.Aggressive

Peaceful

Maximum size 15cm

0 cm 15 cm 30 cm

Recommended Stocking

100 litres

Reef safe

With caution

Diet

Herbivore – Decorator Urchins primarily feed on film algae, hair algae, turf algae, macroalgae, coralline algae, and biofilm found on live rock and aquarium surfaces. They are active grazers capable of consuming large amounts of algae and are often used to help manage nuisance algae outbreaks. In very clean aquariums, supplemental feeding with seaweed sheets (nori), macroalgae, or algae wafers may be required.

Avoid these pitfalls

Common mistakes to avoid

Learn from these common pitfalls when caring for marine livestock.

Trochus Snails require algae and biofilm to graze. Sterile tanks may not provide enough food initially.
Low nutrient systems can remove natural algae sources, requiring supplemental feeding.
Decorator Urchins frequently carry loose objects on their body and may pick up unsecured coral frags, rubble, or decorations.

Help centre

Frequently asked questions

Find answers to common questions about our products and shipping.

This is completely normal behaviour. Decorator Urchins intentionally place shells, rubble, macroalgae, and other objects on their body as camouflage and protection from predators and bright light.
Yes. Unsecured coral frags are commonly carried around the aquarium by Decorator Urchins. This is one of the main reasons reef keepers should ensure frags are properly glued or secured.
Absolutely. Decorator Urchins are among the most effective algae grazers available and can consume significant amounts of hair algae, turf algae, and film algae in established reef aquariums.
Newly introduced specimens, recently stressed individuals, or urchins that lack suitable materials may temporarily stop carrying objects. Most healthy Decorator Urchins eventually resume this natural behaviour.
Yes. Like many sea urchins, Decorator Urchins commonly graze coralline algae along with nuisance algae. Hobbyists aiming to maximise coralline growth should consider this before adding one.
Healthy Decorator Urchins actively move around the aquarium, maintain strong attachment to surfaces, respond to touch, and display intact spines and tube feet.