The phylum Arthropoda contains the most species out of all
the phylums in the animal kingdom. Familiar examples of Arthropods are
spiders and insects. The arthropods found at the Shark River Mudflats are
of the groups Crustacea (crabs, shrimp) and Chelicerata (horseshoe crabs).
All Arthropods share some common characteristics such as a segmented body and
jointed paired, segmented legs. Arthropods also have a hard exoskeleton,
or cuticle, which is made out of chitin that is secreted by the organism.
Because the hard cuticle cannot expand as the body of the arthropod grows, the
organism must periodically shed the cuticle and grow a new one. This
shedding is a process called ecdysis or molting.
Below are some examples of Arthropods found at the Shark
Flat-browed Mud Shrimp
Habitat: burrows in sand and mudflats
Range: Cape Cod to Florida and Texas, West Indies to Brazil
Long-clawed Hermit Crab
Habitat: sand, mud, weed bottoms along the open shores of estuaries
Range: Nova Scotia to Florida to Texas
As seen in the photo to the left, these hermit crabs are very
tiny, only about one inch in length. Unlike most arthropods, hermit crabs
don't grow their own shells. Instead whenever they outgrow their old
shells, they move into a larger shell that a snail has left behind. Hermit
crabs are most commonly associated with pets bought at beachfront stores;
however, these hermit crabs are the ones found for sale. These crabs can't
survive that long out of water.
Habitat: rocks, jetties, mud banks, coastal wetlands, tidepools, open shore and brackish waters
Range: Nova Scotia to New Jersey
These crabs are only 3 - 4 inches wide, and as seen in the above picture can fit in the palm of your hand. The Green Crab originally came from Europe, but now is the most common crab along the shores of New England. Look in the picture to the left. Can find the crab? It's hidden because the Green Crab is camoflauge so it can hide in the algae that floats in the shallow pools of the mudflats. Without this adaptation, the Green Crab would become a tasty treat for seagulls.
Red Oppossum Shrimp
Habitat: tide pools, underocks and shells
Range: Bay of Fundy to New Jersey
This shrimp is very small at only 1/2 and inch long. It likes to hide in pools of water under rocks and shells, especially the shells of the surf clam. The Red Opossum Shrimp is also a very important part of the food chain in coastal ecosystems.