Cryptolithodes sitchensis

Cryptolithodes sitchensis, known as the umbrella crab and the turtle crab,^[3][4] is a species of king crab native to coastal regions of the northeastern regions of the Pacific Ocean, ranging from Sitka, Alaska to Point Loma, California.^[5] Its carapace extends over its legs such that when it pulls in its legs, it resembles a small stone. It lives in rocky areas from the low intertidal to depths of 37 m (121 ft).^[5][6]

Cryptolithodes sitchensis
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Malacostraca
Order:	Decapoda
Suborder:	Pleocyemata
Infraorder:	Anomura
Family:	Lithodidae
Genus:	Cryptolithodes
Species:	C. sitchensis
Binomial name
Cryptolithodes sitchensis Brandt, 1853[1]
Synonyms[2]
Cryptolithodes altafissura Spence Bate, 1865 Cryptolithodes alta-fissura Spence Bate, 1865

Description

Cryptolithodes sitchensis' carapace is ovate, nearly smooth, and extends over all of its three pairs of walking legs and two chelipeds.^[7][4] It is generally about 5⁄3 as wide as it is long and can be over 5 cm (2.0 in) wide at the adult stage.^[4] It ranges from neutral sandy colors to bright oranges, reds, and purples.^[4][8] In adults, the first abdominal segment is fused with the second.^[9] The third, fourth, and fifth segments are each composed of one median (inner) plate and a pair of lateral (outer) plates, although the third segment has accessory plates in two small regions on the left and right surrounded by the second segment, third median plate, and third lateral plates.^[9] Males have an equal number of these plates on both sides, but females often have more accessory plates to the left of the median.^[9]

Taxonomy

Cryptolithodes sitchensis was described by naturalist Johann Friedrich von Brandt in 1853 from a specimen found near Sitka, Alaska.^[1] It is one of the three species of Cryptolithodes, along with C. typicus and C. expansus.^[10]