Crustaceans

Sand crabs dig holes in the beach and rock crabs hide in crevices. Barnacles may not look like typical crustaceans but they are highly modified versions of the crustacean body plan. Goose barnacles are the ones often seen attached by a flexible stalk to cuttle bones or wire weed. Acorn barnacles are the ones without a stalk.

Click on an image for a bigger picture (opens in new window).

 Common nameScientific nameDescription
Goose Barnacles(Arthropoda: Crustacea: Cirripedia: Lepadomorpha)Surprisingly barnacles are crustaceans – relatives of the crabs and shrimps. In fact the free-swimming larval stages of barnacles are shrimp-like creatures. The adult is a sedentary filter-feeder – it lies on its back, attached to a rock, and kicks food into its mouth with its tiny legs. Goose Barnacles are the group that have a rubbery stalk and attach themselves to floating objects such as cuttlebones. Acorn barnacles are more rigid and attach themselves directly to rocks. In this photo the barnacles are attached to a cuttlefish.
Planes major, often referred to as a Columbus crab, on Dead Man's
Fingers.
This is a pelagic crab mostly found on flotsam. The species has
variable colours. It may be uncommon in our waters.