Phylum Arthropoda
Class Crustacea
Subclass Cirripedia (barnacles)
Balanus glandula (acorn barnacle)
These dingy whitish or gray volcano-like organisms range up to 2 cm wide. They are equipped with fan or fern-like appendages that come out at high tide to sweep food into their centrally located mouths.
Chthamalus dalli (small northern barnacle)
These miniature, pale gray barnacles grow no greater than 8 mm in diameter and half as high. They can be found attached to rocks in the bay, and in estuaries.
Pollicipes polymerus (goose-neck barnacle)
These barnacles resemble the head and neck of geese.
Normally, they are found in patches among the mussels pointing in the same direction. They grow up to 8 cm tall with white shell plates and a black wrinkled neck. In addition, they have sweet-tasting flesh. (more image 1)
Semibalanus cariosus (thatched barnacle)
Larger than their cousin, Balanus glandula, these conical and star-like barnacles often resembles a thatch-like roofing. These range in size from 5 cm to 10 cm depending on crowding conditions. The age of these barnacles can be estimated by the erosion of their ridges.
Tetraclita rubescens (pink barnacles)
These pretty, pink thatched-roof barnacles are probably the largest barnacles found at Pillar Point,
growing up to 3 cm in width and length. They are commonly found isolated from other pink barnacles in the lower intertidal zone.
Subclass Copepoda
Subclass Malacostraca
Order Amphipoda
Order Decapoda
Infraorder Caridea
Infraorder Thalassinidea (ghost and mud shrimps)
Callianassa californiensis (bay ghost shrimp)
This whitish crayfish-like organism can be found up to 12 cm in length. Its carapace is smooth with unequal-sized pincers. They are found in abundance, burrowing in sand and mud flats of bays and estuaries.
Infraorder Anomura (hermit, porcelain and mole crabs)
Pagurus hemphilli (middle tide zone hermit crab)
This hermit crab is characterized by the wrist of its big claw bending at a sharp angle, and the brownish red dots with blue granules on its carapace.
Pagurus hirsutiusculus (hairy-legged hermit crab)
Found in quiet waters, this small hairy creature varies up to 7 cm in length. It has a brown body and white or bluish white bands on its legs. Hermit crabs find their home in shells of snails.
Pagurus samuelis (high tide zone hermit crab)
These hermit crabs have a pair of small scarlet antennae and bright blue bands at the tips of the feet. They are commonly found living in the high tidal zone in the empty shells of the black turban snail. Similar to property owing Americans, they will fight for possession of these shells with other hermits.
Infraorder Brachyura (true crabs)
Cancer productus (red cancer crab)
Often found buried under rocks in sandy areas, this tasty creature (a staple of seafood restaurants) has a distinctive brick-red
carapace up to 16 cm wide. This creature dominates the beaches at night feeding in the lower tidal zone.
Hemigraspus nudus (purple shore crab)
Slightly larger than its cousin Pachygrapsus crassipes, this shore crab has a carapace that varies up to 6 cm in width in males and 4 cm in females. The body is usually purple, sometimes greenish yellow or reddish brown in color with purple or red spots on the claws.
Pachygrapsus crassipes (lined shore crab)
Smaller than its cousin Hemigraspus nudus, the carapace is up to 5 cm wide and is usually green in color with wavy white lines or stripes.
It can also be dark red or another color variation and may be with or without stripes. It has a squat, flat, squarish body. Unlike other crabs, Pachygrapsus crassipes can scurry away sideways or backwards in response to danger.
Pugettia gracilis (graceful kelp crab)
Smaller than its cousin Pugettia producta, the carapace of this crab measures up to 4 cm wide and is brown, yellow, or red in color. The graceful appearance of this crab in contrast to Pugettia producta is the source of its common name; however, it does not lack the same powerful claws or dangerous spines.
Pugettia producta (shield blacked kelp crab)
Commonly found on kelp, the carapace of this crab measures up to 9 cm wide. Its shell is smooth and shield-shaped. It ranges from reddish or olive brown in color and has slim but powerful claws. Along its legs and carapace are sharp spines that are for clinging to the seaweed on which it feeds.
Order Mysidacea
Order Isopoda
Class Pycnogonida
