Scarlet King Crab (Lithodes couesi)
The Scarlet King Crab is a deep-sea crab found at depths below 350 m along the Pacific coast of the USA, from Alaska to California. Males can grow to up to 108 mm in length and females can grow up to 92 mm in length. These crabs have long slender legs that are believed to be an adaptation to their deep sea life. 
The skinny legs require less muscle allowing for the crab to keep up its energy with a small amount of food. This is important because food can be scarce in the deep sea. Their legs also allow them to take fewer steps and still cross the same distance as well as spreading out their body weight to keep them from sinking into the substrate. The Scarlet King Crab has been seen at multiple locations along Hydrate Ridge. They are often found in sandier substrate, however they were also seen among a large group of egg-laying snails.
References:
Marine Life Field Guide (Neptune Canada)
https://www.afsc.noaa.gov/kodiak/photo/alvlithscar.htm
