Emerita analoga

Taxon-Order: 
Decapoda

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Distribution: 
Alaska to Baja California
Habitat: 
Adults: in the intertidal zone of sandy beaches
Size: 
Larvae 0.7-3.5 mm; adults 10-35 mm carapace length
Diet: 
Larvae are filter feeders and adults feed on various plankton.
Predators: 
Adults are food for birds, mammals, and fishes.
Useful Facts or Characters: 

There are 5 zoea stages; zoea stage I is characterized by a short rostral spine and absence of lateral spines on the carapace.  Zoea stages II-V are characterized by a long rostral spine and two long, stout, postero-lateral carapace spines.  The telson of zoea stages I-V is broad and flat and armed with about 26 spines.  Adults do not have claws or spines but have two pairs of antennae to gather food and oxygen.

Natural History: 

Commonly called the sand crab or mole crab. Adults are use in neurological studies because the crab's tail has the largest sensory neurons found in any animal.

References: 

http://www.farallones.org/documents/sandcrab.pdf

Johnson, M.W., and Weldon, M.L. (1942) Pelagic larval stages of the sand crabs Emerita analoga (Stimpson), Blepharipoda occidentalis Randall, and Lepidopa myops Stimpson. Biological Bulletin 83: 67-87.