Image of whiteknee hermit crab

Description:

In this side view the slight coiling of the "house" is seen. The house is made of the hydroid Hydractinia milleri. The egglike structures are gonozooids of the hydroid. The hermit crab gives no sign of being stung by the hydroid. Some other species of hermit crabs, known to be symbiotic with Hydractinia, also do not seem to be vulnerable to their sting while some other hermit crab species are.