Assuming They Won't Touch Corals

Decorator Crabs may remove pieces of soft corals, zoanthids, sponges, or macroalgae to use as camouflage.

Keeping Them in Frag Tanks

Their habit of climbing and decorating themselves can result in unsecured coral frags being moved or damaged.

Underestimating Their Nocturnal Activity

Many Decorator Crabs are most active after lights out, when they spend hours foraging and collecting new camouflage materials.

Why is my Decorator Crab ripping pieces off my corals?

This is one of the most common behaviours seen in Decorator Crabs. They often collect pieces of soft corals, zoanthids, sponges, macroalgae, and other materials to attach to their shell as camouflage. This is why they are classified as reef safe with caution.

What does a Decorator Crab stick to its shell?

Decorator Crabs use specialised hooked hairs on their exoskeleton to attach materials such as macroalgae, sponge, coral fragments, hydroids, and even small pieces of detritus. Every crab develops its own unique appearance.

Are Decorator Crabs safe with zoanthids and soft corals?

Not always. While they rarely eat healthy corals outright, they may remove polyps or tissue to use as camouflage. Reef keepers with prized zoanthid collections should monitor them carefully.

Can a Decorator Crab change its decorations?

Yes. Decorator Crabs frequently remove old camouflage and replace it with new materials as they grow, moult, or encounter more desirable decorations within the aquarium.

Do Decorator Crabs eat nuisance algae?

Many species will graze on algae and detritus while foraging, although they should not be considered dedicated algae-control animals like Sea Hares, Urchins, or certain snails.

Why has my Decorator Crab suddenly become bare?

This often happens after moulting. Following a moult, the crab must collect and attach new camouflage materials, which can take several days or weeks.

Sold out

Aquamarine Aquaristic

Spider Decorator Crab (Paranaxia serpulifera)

Name: Spider Decorator Crab (Paranaxia serpulifera)
Brand: Aquamarine Aquaristic
SKU: 47495540113654
Price: 45.0 AUD
Availability: OutOfStock

$45.00 each

Out of stock

Spider Decorator Crab (Paranaxia serpulifera) Description The Spider Decorator Crab is one of the most extraordinary marine invertebrates available to reef hobbyists. Native to Australian waters, this species is renowned...

Read full description →

Arrive Alive guarantee Replacement or store credit

Door-to-door delivery Australia-wide options

Secure checkout

Description

Spider Decorator Crab (Paranaxia serpulifera) Description

The Spider Decorator Crab is one of the most extraordinary marine invertebrates available to reef hobbyists. Native to Australian waters, this species is renowned for its incredible camouflage abilities, attaching sponges, algae, tunicates, and other materials to its body to blend seamlessly into its surroundings. Its long legs, unusual body shape, and ever-changing appearance make it a true conversation piece. While generally peaceful, the Spider Decorator Crab's natural decorating behaviour means it may occasionally collect material from corals and other sessile invertebrates, making it best suited to carefully planned reef aquariums.

Shipping To Tasmania	NO
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

Decorator Crabs are omnivorous and feed on: Algae, Detritus, Uneaten fish food, Frozen marine foods, Small meaty foods, Organic matter

Avoid these pitfalls

Common mistakes to avoid

Learn from these common pitfalls when caring for marine livestock.

Decorator Crabs may remove pieces of soft corals, zoanthids, sponges, or macroalgae to use as camouflage.
Their habit of climbing and decorating themselves can result in unsecured coral frags being moved or damaged.
Many Decorator Crabs are most active after lights out, when they spend hours foraging and collecting new camouflage materials.

Help centre

Frequently asked questions

Find answers to common questions about our products and shipping.

This is one of the most common behaviours seen in Decorator Crabs. They often collect pieces of soft corals, zoanthids, sponges, macroalgae, and other materials to attach to their shell as camouflage. This is why they are classified as reef safe with caution.
Decorator Crabs use specialised hooked hairs on their exoskeleton to attach materials such as macroalgae, sponge, coral fragments, hydroids, and even small pieces of detritus. Every crab develops its own unique appearance.
Not always. While they rarely eat healthy corals outright, they may remove polyps or tissue to use as camouflage. Reef keepers with prized zoanthid collections should monitor them carefully.
Yes. Decorator Crabs frequently remove old camouflage and replace it with new materials as they grow, moult, or encounter more desirable decorations within the aquarium.
Many species will graze on algae and detritus while foraging, although they should not be considered dedicated algae-control animals like Sea Hares, Urchins, or certain snails.
This often happens after moulting. Following a moult, the crab must collect and attach new camouflage materials, which can take several days or weeks.