Meet Our Critters

Our programs and talks are full of information as well as awesome live sea creatures!  We take more animals to schools, parties, festivals and special events than anyone else.  Check out some of our critters.  Click on the picture for a close-up.

Porifera - The Sponges

This phylum contains about 5000 species of simple animals that lack distinct organs, have skeletons of spongin, calcium carbonate spicules, silica spicules or a combination of spongin and silica spicules.  They filter feed on plankton but recently a species was discovered near France, that engulfs shrimp!​

Red Beard Sponge

Microciona prolifera - a right red to orange colored branching sponge found in the Chesapeake Bay

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Arthropods ​

This huge phylum includes insects, arachnids, and crustaceans to name just a few.  There are well over one million species in this phylum.​

Box Crab

Lopholithodes foraminatus - The Box Crab has two different sized claws for crushing and picking up food. Crabs actually breathe through their armpits! They take in water under their claws and blow 'bubbles' out of their mouths.

Atlantic Horseshoe Crab

Limulus polyphemus - Horseshoe crabs are not crabs at all but are actually arthropods – 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.

Grass Shrimp

Palaemontes pugio - This small type of shrimp is often found hiding in grasses, hence the name.  Like other shrimp, they have a spine that sticks out over their eyes, called rostrum, for protection.

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.

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. How do you tell a male crab from a female crab, you ask?  Female crabs, called “Sallys,” have red tips on their claws like nail polish, and the underside of their shell is dome shaped like the Capital Building.  Male crabs, called “Jimmys,” lack the red claw tips, and the underside of their shell is shaped like the Washington Monument.  Blue crabs eat marsh periwinkle snails. 

Atlantic Blue Crab

Callinectes similis - Looks very similar to the edible blue crab but rarely grows to more than 5" across the shell (the record for C. sapidus is 10 1/2"!)

Mud Crab

Panopeus duorarum - Mud Crabs are very small crabs which only grow to about 1-2” across.  They hide by burying in the mud or hiding under rocks or logs underwater.  Ours were most collected in VA Bch.

Stone Crab

Menippe mercenaria - This little girl was donated by the Owens Science Center in MD back in April 2001.  Her shell will eventually reach eight inches across!

Striped Hermit Crab

Clibanarius vittatus - A hermit that tends to be found in moon snail shells.  We have at least four that were collected in VA Bch.

Long-claw Hermit Crab

Pagurus longicarpus - These guys don't get too large but they sure can walk fast!  We have at least four that were collected in VA Bch.

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This large phylum includes snails, clams, oysters, chitons, squids and octopi.  They are characterized by their mantle, a unique organ to this group, that in most cases, secretes the shell.  There are over 100,000 species of Molluscs in the world!

Blue Mussel

Mytilus edulis - A bivalve that is popular to eat!  They produce byssal threads that help them hang onto rocks and other blue mussels, thus avoiding getting tossed up on the beach.

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.


Channeled Whelk

Busycotypus canaliculatus - A large snail that eats soft clams.  We currently have one that has been with us for over 3 years.

Veined Rappa Whelk

Rapana venosa - This type of snail is actually from Japan.  recently it has been appearing in the Chesapeake Bay, threatening the native species of snails like the Knobbed and Channeled Whelk.  

Florida Horse Conch

Pleuroploca gigantea - The second largest snail species in the world, growing 2' in length.  These carnivorous snails have orange skin!  Perfect for Halloween!

Crown Conch

Melongena corona - A 3" snail found all over the West coast of Florida, preying upon oysters.  This one has algae growing on its shell.  It is not normally green!

Eastern 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.

Lettered Olive Snail

Oliva sayana - Our lettered olive snail has been with Under the Sea since the very beginning - way back in 1995!  He spends most of his time buried in the sand.

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.

Eastern Oyster

Crassostera virginica - Oysters are perhaps the most important animal in the Chesapeake Bay.  As filter feeders, they are crucial for removing sediment that prevents seagrasses from getting enough sunlight and other particulate pollution from the Bay.  But oysters are in trouble.  As a result of disease and overfishing, oyster populations are struggling to remain robust.  Scientists, policy makers, and oystermen are all working together to create laws to help oyster populations rebound.

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Echinoderms or Spiny Skinned Critters​

Echinoderms are characterized by their spiny skin and pentagonal body designs.  Although they appear to have radial symmetry, it is secondarily developed.​

Brittle Star

Ophiarachna incrassata - a nocturnal invertebrate living on coral reefs. Sea stars belong to a group of animals called echinoderms 'spiny skin' that can regenerate lost arms or rays.

Purple Sea Urchin

Arbacia punctulata - A Mid-Atlantic species with sharp, 1"-2" spines similar to toothpicks.

Pencil Spine Sea Urchin

Eucidaris tribuloides - A tropical species that is not dangerous to touch.  Its spines are thick and blunt, used to wedge the urchin in rocky crevices. 


Sand Dollar or Keyhole Urchin

Mellita quinquiesperforata - Keyhole Urchins are not true sand dollars, but they are actually flattened cousins of sea urchins.  Keyhole urchins get their name from the opening, or keyhole, near the center of their shell.

Forbes Common Sea Star

Asterias forbesi - Found off the VA/MD coast around mussel beds.  This is a good look at its underside. 

Brown Spiny or Orange Sided Sea Star

Echinaster spinulosus - a tropical species of sea star.

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These animals have a vertebral column that protects the notocord.  There are five major groups: Birds, Amphibians, Reptiles, Fishes, and Mammals.​

Yellow Tailed Blue Damsel Fish

Chrysiptera parasema - a reef fish that prefers shallow water. One of the smallest types of damsel fish. Young damsels group together in schools for protection from predation.

Brown Banded Bamboo Shark

Chiloscyllium punctatum - The brownbanded bamboo shark inhabits nearshore coral reefs, where it hunts for its favorite foods – crabs, shrimps, and small fishes – at night.  It can find these snacks even in the dark because of its barbels, whisker-like sensory organs that it uses to search through the sand.  Brownbanded bamboo sharks only grow to be about three feet long, and they are not a threat to humans.

Chain Dogfish

Scyliorhinus retifer - found in the Atlantic Ocean at depths exceeding 120 ft. A cold water species often found off the coast of the Chesapeake Bay. Most sharks have 5 pairs of gills to breathe underwater. Sharks have a sixth sense called electroreception allowing them to detect electrical impulses and find prey by listening for its heartbeat.


Chrysiptera cyanea - Another flatfish that is basically a small flounder.  More properly it is a type of sole.  During the colonial days, pig farmers would try to feed this by catch to their animals, resulting in its now common name.

Summer Flounder

Paralichtys dentatus - Growing to about three feet, these fish are a prized food fish.  The one we currently have was donated to us by Dr. Bill Hall of the University of Delaware.

Yellow Stingray

Urolophus jamaicensis - A small tropical species that can travel to parties as well as schools.  It is happiest when buried.


Belle siegfried - A very loveable species but rare.  This one was spotted at Halloween in Kathy's house, swimming around.