The scaly rock crab is a tropical Indo-Pacific crab of wave-washed rocky shores, named for its bumpy shell that looks as if it were covered in scales. In the US, it's native to Hawaii. It often hitches rides far out to sea on floating debris and sea turtles, which is why it's called a rafting crab.
Appearance
- Appearance
- The oval, domed shell is about 2–2.4 in (5–6 cm) across and covered in small bumps. Its colors mix brown, blue, purple, and orange. The claws are short and slender, and the walking legs are fringed with short hairs and end in sharp tips.
Where it lives
- Typical habitats
- Rocky shores
- Intertidal zone
- Open ocean (rafting)
- Range
- Tropical waters of the Indian and Pacific Oceans, including Hawaii, where it's native. It has also been reported recently from the Mediterranean Sea.
- Preferred conditions
- Usually just below the waterline on rocky shores, but it also turns up in the open ocean clinging to floating objects or animals.
Behavior
- Diet
- Mostly plant material, with the occasional small .
Name and classification
- About the name
- It used to be treated as a subspecies of the Atlantic tidal spray crab (Plagusia depressa), and older Hawaiian reports use that name. Genetic and larval differences now set it apart as its own species. The old name Plagusia tuberculata belongs to this crab too.
Conservation
- IUCN Red List
- NENot EvaluatedNot yet assessed
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