Meet the Animals: A Day at the Beach
Horseshoe Crab (Limulus polyphemus): Horseshoe crabs are not crabs at all but are actually close relatives of scorpions and spiders. This not-crab has 12 legs with a mouth in the center, 10 eyes, and blue blood. Horseshoe crabs have been on this planet longer than dinosaurs – 300 million years, and they are an invaluable link in the Chesapeake Bay food web. Horseshoe crabs crawl on shore from May-June in order to reproduce, and their eggs and larvae are important food for fishes, sea turtles, and migrating sea birds.
Blue Crab (Callinectes sapidus): The blue crab is a commercially important crustacean in the Chesapeake Bay. The blue crab fishery in the Bay nearly collapsed in the ‘90s and early 2000s, but is recovering thanks to new legislation. New laws included setting restrictions on what time of day fishers could collect crabs, restricting fishers to only taking crabs that are above a certain size, and requiring that fishers only take male crabs. Female crabs, called “Sallys,” have red tips on their claws like nail polish. Male crabs, called “Jimmys,” lack the red claw tips.
Black-Fingered Mud Crab (Panopeus herbstii): Black-fingered mud crabs are so-named for the black tips on their claws. These crabs are a crucial element of Chesapeake Bay food webs because they eat marsh periwinkle snails. Without mud crabs to keep their population in check, periwinkle snails could destroy wetland ecosystems by eating all the marsh grasses.
Spider Crab (Libinia emarginata): Spider crabs are also known as decorator crabs. Their backs and legs are covered in soft algae that acts like velcro, and the crabs can stick pieces of shell and seaweed to themselves in order to camouflage. Spider crabs aren’t just good at hiding; they’re good at seeking, too. They may not very good eyesight, but spider crabs have tasting and sensing organs on the tips of their feet to help them find food.
Striped Hermit Crab (Clibanarius vittatus): Hermit crabs have soft bodies with curly tails that they protect by wearing snail shells on their backs. In order to better camouflage, this species of hermit crab has been known to attach sea anemones to its shell. Just like sea anemones and clownfish, the crab and the anemone have a mutualistic symbiotic relationship: the anemone’s stinging tentacles protect the crab from predators, and the anemone gets a mobile home on which to live.
Mud Snail (Tritia obsoleta): Mud snails may look like babies compared to larger whelks and conchs, but these tiny surf zone dwellers are fully grown. They live on the beach where there is nearly constant wave action, and often these little snails are knocked onto their backs by the rushing water. But that’s okay! Mud snails can use their foot to grab the sand and flip themselves right side up.
Knobbed Whelk (Busycon carica): Whelks are giant sea snails. They have a soft body protected by a hard shell that they make and remain in their entire lives. A knobbed whelk uses its shell to break off pieces of clam shells, and then sticks its tongue inside to scoop out the clam meat. The “tongue” of a whelk is called a radula, and it is rough like a cat’s tongue because it is covered in tiny teeth.
Chesapeake Bay Clam (Mercenaria mercenaria): The Chesapeake Bay hard clam can be known by many different names – quahog, cherrystone, little neck, or chowder clam – depending on its size. No matter their name or size, all clams of this species are filter feeders. Their mouth is made up of a pair of siphons – one for sucking in food and one for expelling the water that comes in with that food.