Porcelain crab
Petrolisthes militaris
This porcelain crab is one of the most abundant crabs on tropical Australian reefs. They characteristically flattened body helps this crab to squeeze into tight spaces between bits of coral rubble and stones. Porcelain crabs are filter feeders and have large feathery mouthparts for collecting food from the water column. The large claws are therefore used defensively, but are more likely to be autotomised (fall off) to distract predators, much in the same way a lizards tail is.
Morphology
Dorso-ventrally flattened body, claws with distinct sculpturing and often a fringe of 'hair' along anterior margin.
Evolution
The porcelain crabs are not true crabs, but are the result of an independent but convergent evolutionary lineage more closely related to hermit crabs.
Behaviour
Porcelain crabs are shy creatures, and will very quickly retreat from threats. They can use their abdomens to swim backwards by rapidly flicking it, much like a shrimnp would.
Habitat
Marine
Shallow water, <30 m. found in reef habitats typically in rubble.
Distribution
Indo-West Pacific
| Kingdom: | Animalia |
|---|---|
| Phylum: | Arthropoda |
| Subphylum: | Crustacea |
| Class: | Malacostraca |
| Subclass: | Eumalacostraca |
| Order: | Decapoda |
| Suborder: | Pleocyemata |
| Infraorder: | Anomura |
| Superfamily: | Galatheoidea |
| Family: | Porcellanidae |
| Genus: | Petrolisthes |
| Species: | militaris |
| Name Published Year: | 1862 |
|---|---|
| Scientific Name Authorship: | Heller |
| Commercial Impact: | None |
| Conservation Assessment: | Least Concern |
Cite this page
Western Australian Museum Collections https://museum.wa.gov.au/online-collections/names/Petrolisthes-militaris
Accessed 26 Apr 2025
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