Decorator Crab
Seaweed Crab
Click to enlarge image
© Australian Museum
Fast Facts
-
Classification
- Genus
- Naxia
- Species
- tumida
- Subfamily
- Majinae
- Family
- Majidae
- Suborder
- Pleocyemata
- Infraorder
- Brachyura
- Order
- Decapoda
- Class
- Malacostraca
- Subphylum
- Crustacea
- Phylum
- Arthopoda
- Kingdom
- Animalia
-
- Size Range
- 4 cm
Introduction
The Decorator Crab looks like seaweed on the move.
Identification
The Decorator Crab's carapace is covered with hooks to attach algae, seaweed or anything in the environment that will assist in camouflage.
Decorator Crab
Image: Dr Isobel Bennett© Australian Museum
Habitat
The Decorator Crab lives on intertidal rocky shores.
Distribution
The Decorator Crab is found in the temperate waters of Australia in New South Wales, Victoria, Tasmania and Western Australia.
Other behaviours and adaptations
Once a suitable covering is found, the Decorator Crab snips it off with its pincers, coats the end with a special gland secretion that hardens in seawater, and deliberately places it onto its carapace. The crab continues the process until it is sufficiently covered. The algae continue to grow once attached, helping the concealment.
This and other decorator crabs belong to the 'spider crab' family, Majidae. This group includes the largest crab in the world - the Giant Japanese Spider Crab (Macrocheira kaempferi) with a leg span of over 2 m.
