Spider Crabs

Spider Crab

Spider Crabs Libinia emarginata are scavengers. Although they are fearsome-looking, they are actually slow-moving, and their usual claws-out threat display is mostly bluff. Spider Crabs have relatively small round bodies (to 4"), long legs, and rather weak claws. They are found subtidally to at least 160 ft, on any type of bottom, and are very common in rivers and inlets. They often cover themselves with detritus for camouflage, and can also burrow in soft sediments.

A related species is used for food in Europe. The only thing more unattractive than a Spider Crab is two of them mating.

Spider Crab
A large adult Spider Crab
Spider Crab
Looks like one of those old Japanese monster movies, doesn't it?
Spider Crab
A baby Spider Crab, decorated with algae that it has stuck to itself for camouflage
Spider Crab
A small specimen trailing a veil of algae
Spider Crab
I'm not sure what these two spider crabs were doing, and I'm sure I don't want to know !
Herb Segars Photography

Teredo

Teredo navalis

Size: to 5 "

This worm-like creature is actually a bivalve mollusk with a greatly reduced shell, which it uses to bore tunnels into wood. They typically spend their entire lives in a tunnel in a single piece of wood. In addition to feeding off the wood, they can also filter feed like ordinary bivalves.

In the age of wooden ships, teredos and other wood-borers were a tremendous problem. In our area, more wood-boring is done by crustaceans than Teredos.