Snow Crab: Chionoecetes opilio (J.C. Fabricius, 1888)
A very common harvested spider crab of Arctic shelf seas
Size
- Male carapace length 69.3, width 69.3 mm
- Female carapace length 53.8, width 54.5 mm
Color & Characteristics
- Light brick red above, may be iridescent, below yellowish white; sides of legs white
- Carapace about as long as wide, tuberculate (bumpy) with prominences becoming more acute anteriorly and at sides, rostrum short
- Chelipeds (pinchers) short
- Merus (upper part) of walking leg rather flat and dilated
Habitat & Distribution
- Mud, sand and shell, 13-2187 m
- Most records are from no more than 110 m
- Disagreement remains whether different populations represent valid subspecies
Feeding
- Scavenger, predator on annelid worms, crustaceans, brittle stars and mollusks
Life cycle
- Like related spider crabs (superfamily Majoidea), snow crabs go through a final molt before they mate and die
- Fertilization is internal
- Females carry up to 150,000 fertilized eggs under the abdomen
- Hatching coincides with the major plankton bloom of late spring or early summer
- They hatch as pelagic zoeal stages, metamorphose into megalops stages and settle to the sea floor
- The life span is 5-6 years
More Biology and Ecology
- Snow crabs are related to tanner crabs (C. tanneri) and similar species found in cold northern seas
- Can be caught in large numbers, their relatively thin exoskeleton compared to other spider crabs make a desired ccomercial species
- A good general source of information is “Snow crab: a successful fishery” by Chadwick & Moriyasu, 1996
- Two gammarid amphipods, Ischyrocerus commensalis and Gammaropsis inaequistylis, have been found living on the carapace of the snow crab off Newfoundland
Page Author: Mary Wicksten
Created: August 5, 2010
