|Kingdom Animale | Phylum Arthropoda | Subphylum Crustacea | Class Malacostrata|
The most common littoral rock species is the bluish-black Petrolisthes lamarcki (up to 2cm diameter). Almost all are filter feeders, using their hairy mouthparts to actively trap small animals in the water. They are not true crabs, and are easily distinguished from them by appearing to have only 8 limbs (including the pincer). The tenth pair is greatly reduced and is usually tucked under the abdomen.
From A Guide to Seashore Life by Dr Leo W H Tan and Peter K L Ng
Published by the Singapore Science Centre and sponsored by BP
@Raffles Museum of Biodiversity Research and Singapore Science Centre