Cape Cod's Nature Place

The Cape Cod Museum of Natural History

Aquarium: One Cape / Many Waters

The Cape, a natural masterpiece, has a remarkable diversity of both freshwater and saltwater habitats for visitors to experience.

In our aquarium, our goal is to help you discover the exciting nature and science in nearby ponds, streams, creeks, marshes, beaches, tidepools and Cape Cod Bay... all here at Cape Cod's Nature Place.

Like Cape Cod, our aquarium is ever-changing and exciting. Here are some of the incredible animals you might see!


The Grass Shrimp (Hippolyte sp.) is found in coastal oceans, especailly ell beds from Cape Cod to the Gulf of Mexico. They are only about 3/4 of an inch (2 cm) long. Their diet consists of phytoplankton and zooplankton. They color of grass shrimp varies to match their habita, for example Grass Shrimp that live among blades of eel grass are typically green.


You may have seen a Moon Snail (Lunatia heros) during a walk on the flats of Cape Cod Bay, but they can be found from   Massachusetts to the Gulf of Mexico. They are found in coastal oceans, mostly on sandy bottoms. They grow to be about 3 inches (8 cm) in diameter on a diet of clams and other mollusks. It uses its radula, a tooth covered "tongue", to drill through the shell of their prey and then suck out its dinner!


Channeled Whelk (Busycon canaliculatum) can be found in coastal estuaries and inshore oceans from Massachusetts to northern Florida. They grow to be about 7 inches (18 cm). They feed on clams and other mollusks by prying shells open with their muscular foot and then scraping out the flesh with their radula, a kind of tooth covered tongue! You may see these gastropods in seafood markets as "scungilli".


White Perch (Morone americana) is found in coastal oceans, estuaries, and rivers from Nova Scotia to North Carolina. On Cape Cod they can be found in ponds. They grow to be about 19 inches (48 cm) on a diet of shrimp, crab, shrimp, and squid. These fish are related to Stiped Bass but prefer brackish waters.

The Bullfrog (Rana catesbeiana) is found in marshes and ponds from southern Canada to central Florida. They grow to be about 6 inches (15 cm) long on a diet of mice, birds, frogs, and other small animals. Look for a circular "crater" to the rear of each eye. This is the frogs tympanic membrane (external eardrum). The males have larger ears than the females. If you listen you may be able to hear the Bullfrog's deep voice in ponds and wetlands!

Here at the Museum, we headstart baby Horseshoe Crabs. When they first break out of their egg cases as tiny free-swimming larve, we feed them baby brine shrimp. In the wild, of the some 90,000 eggs deposited by each laying female, only 10 survive. These eggs are an important food source for the Red Knot and other migratory birds.


The Knobbed Whelk (Busycon carica) is found in inshore oceans, especially on sandy bottoms, from Massachusetts to Northern Florida. Their diet consists of clams and other invertebrates and they can grow to be about 7 inches (18 cm) long. You may have seen a Knobbed Whelk egg case when you are walking the beach, it looks like a stack of nickels.


The Northern Horsemussel (Modiolus modiolus) can be found along the North American Atlantic coast from Florida and north and as well as the Pacific North American coast from California north and in Europe from British waters north. They are typically 4 inches (10 cm) long. They attach to hard surfaces such as shells and rocks using their byssus threads. They can also attach to the byssus threads of other mussels and form Mussel Reefs!


Have you ever spotted one of our Rock Gunnels (Pholis gunnellus)  in the Tide Pool? In nature, they are found on rocky bottoms from Nova Scotia to Delaware Bay. They grow to be about 6 inches (15 cm) long on a diet of worms and small crustaceans. They are very slippery and sometimes called butterfish!


The Common Periwinkle (Littorina littorea) can be found from Maryland to Labrador attached to any hard surface such as rocks or wharf pilings. They are believed to have been brought over from Europe over a century ago. They can survive out of the water and without food for long periods of time. They are vegetarians and prefer browsing on algae films. In this photo you can get a rare view of the underside of the Common Periwinkle (the small spheres you see... are poop).


American Eels (Anguilla rostrata) are found in the ocean, estuaries, rivers, streams, ponds, and lakes from Labrador to northern South America. They grow to be about 18 inches (46 cm) long on a diet of worms, crustaceans, clams, and fish. The American Eel is a catadromous fish. That means it is born in salt water, grows up in fresh water, and then returns to the sea to spawn. Conversely, river herring are anadromous. They are born in fresh water and then swim to the sea.


Boxly is one of our Eastern Box Turtles (Terrapene carolina). He has a shell that was damaged and although it is it repaired  he would not be able to survive in the wild on his own. Eastern Box Turtles can be found from in woodlands, fields, edges of wetlands, and stream banks, from southern Maine to northern Florida and west to Michigan, Illinois, and Tennessee. The grow to be about 7 inches ( cm) on a diet of insects, earthworms, snails, mushrooms, berries, and leafy vegatables. They typically live about 40-50 years but have been known to live to 100! Mating occurs from April until October. Females can lay 4 to 5 eggs up to 4 years after mating! She wil lay the eggs in the summer and they will hatch about 3 months later. To protect themselves Eastern Box Turtles can completely enclose its body in its shell!


Myrtle is our Diamond-back Terrapin (Malaclemys terrapin)! She will be 29 years old on June 11th! Diamond-back Terrapins are found in coastal estuaries from Cape Cod to Cape Hatteras. Their diet consists of crabs, snails, other invertebrates, and aquatic plants. In spring and early summer females lay eggs in sand dunes. Warmer sand develops produces females and cooler sand produces males.


The Purple Sea Urchin (Arbacia punctulata) is found in intertidal zones up to 700 feet (250 m) deep from Cape Cod to the West Indies. They are about 2 inches (5 cm) in diameter. Their diet consists of algae, invertebrates, and dead marine animals. Much of what scientists know about embryo development was learned by studying the egg development of this species!


Mummichog (Fundulus heteroclitus) is found in coastal estuaries from the Gulf of St. Lawrence to Texas. They grow to 4 inches (10 cm) long and subsist on a diet of eel grass and small crustaceans. You may be able to spot this fish in salt marsh channels if you are observant, it can change it colors to match its surroundings.  Male mummichog's also display scintillating colors when trying to attract females. The name mummichog come from the Narragansett, moamitteaug.


The Brown Bullhead also commonly called a catfish or horn pout in New England (Ameiurus nebulosus) is found in ponds and lakes from Nova Scotia to Florida. They are typically 12 inches (30 cm) long and feed on a diet of larval insects, worms, and crayfish. If you are fishing avoid the jagged barbs on the dorsal (top) and pectoral (side) fins, barb wounds can be painful!


The New England Neptunes (Neptunea lyrata) are also known as the Wrinkled Whelk and Ribbed Neptune. They are found from Nova Scotia to Cape Cod. This marine gastropod was declared the Massachusetts State Seashell in 1987!


The Common Spider Crab (Libinia emarginata) is found in coastal oceans, especially sandy bottoms from Cape Cod to the Gulf of Mexico. Their diet consists of clams and other bivalves. Their legs can reach a span of 12 inches (30 cm)! Although these creatures might look scary with their spider like appearance, they are harmless. Their shells are often the foundation for mobile habitats with barnacles, sponges and seaweed attached.


Green Sea Urchins (Strongylocentrotus droebachiensis) inhabit the intertidal and sub-tidal waters of the North Atlantic from the Artic to Cape Cod. They move about the substrate by using numerous tube feet and their spines. Their growth has been recorded up to 4 inches (10 cm) wide. They are omnivores and will eat small camouflage of fish and sea lettuce. Their mouth has five pointed teeth hiding on their underside. This sea urchin is wearing some of its sea lettuce/lunch on its body. They will often cover their bodies with shells and stones as camouflage.  We never know what our resident urchins will be wearing next!


Green Frog (Rana clamitans) are found in the eastern half of the United States in shallow fresh water, springs, swamps, brooks, and the edges of ponds and lakes. Their diet includes insects, spiders, and tadpoles and can grow to be about 2 to 4 inches (5 to 10 cm).


Our rare 1 in 50 million bi colored lobster molt overnight. Molting can take 15 minutes to several hours. Then it takes the lobster six to eight weeks for the new shell to harden.  During this time in the cycle the lobster is in a soft-shell stage, which make it vulnerable to predators since the exoskeleton is part of their defense mechanism.  In our aquarium lobster tanks, there are no predators, so the lobsters are free to roam around, bury their shells, and eat the shells at their leisure. We tend to celebrate molting around here! (Sort of like a birthday or a holiday!)


The Waved Whelk (Buccinum undatum) is found in shallow waters north of Cape Cod. Their shells grow to be about 4 inches (10 cm) tall on a diet of shellfish and marine worms. You may find a Waved Whelk egg case along the shore. It is a series of segmented semi-transparent sacks that each contain the immature Whelk. The egg case will rattle when shaken.


Steamer or Soft Shell Clams (Mya arenaria) can be found from Cape Cod to Greenland and Great Britain between the tides hidden in sandy, pebbly, or rocky bottoms.  It buries it self right below the surface and projects its siphon into the water so it can feed. It can also use its siphon to eject water and move when disturbed.


The Sculpin (Myoxocephalus spp.) are found in coastal oceans from the shore to off shore depths from the Artic to New Jersey. They grow to be 20 inch (50 cm) long on a diet of worms, crustaceans, and fish. The skin of both the shorthorn and longhorn sculpin contains a protein that protects them from freezing in icy waters.


The Green Crab (Carcinus maenas) are found in coastal oceans especially in intertidal zones and under rocks from Nova Scotia to New Jersey. They grow to be about 3 inches (8 cm) wide on a diet of worms, clams, crustaceans, and mollusks. This species is also called the European Green Crab and was somehow transported from Western Europe to the East Coast of the United States sometime in the early 1800s.


The Red Hake (Urophysics chuss) are members of the Cod family and can be found in ocean depths up to 430 feet from Nova Scotia to South Carolina.  Their habitat is sandy or muddy bottoms especially around structures such as rocks or ledges. They grow to 26 inches (66 cm) on a diet of shrimp, amphipods, crustaceans, squid, and herring. Juvenile Red Hake will live in empty scallops shells and stay close to scallop beds until they mature.


The Atlantic Rock Crab (Cancer irroatus) are found on sand, gravel, and rocky bottoms in estuaries and open shores from Labrador to South Carolina. They grow 3.5 inches (9 cm) long by 5.25 inches (13 cm) wide. They eat a varied diet which includes: algae, worms, mussels, snails, and crustaceans including hermit crabs. Atlantic Rock Crabs like to sneak into Lobster Traps and steal the bait. Sometimes however, they get tapped too....


The Northern Puffer (Sphoeroides maculatus) are found in coastal waters from Newfoundland to Florida. They are normally about 8 inches (20cm) but have been found as large as 14 inches (36 cm).  Their diet consists mostly of shellfish and occasionally finfish.  They use their beak-like mouth to extract meat from shells and can sometime use it to break shells. These puffers are slender, their tough, elastic skin allows them to become round or inflated when they are startled or threatened.


The Striped Sea Robin (Prionotus evolans) is found from coastal estuaries to offshore depths from Massachusetts to Florida. They grow to be about 12 inches (30 cm) long. They enjoy a diet of shrimp, crabs, clams, worms, squid, and fish. They use their large, fan-shapped pectoral (side) fins to stir up food from sandy bottoms. They can also extend modified fin rays from their front lower fins to fell for food on the sea floor.  As they probe the bottom, it appears they are walking!


The Cunner (Tautogolabrus adspersus) is found in coastal oceans - often among eelgrass and dock pilings from Nova Scotia to South Carolina.  They grown to be about 10 inches (25 cm) long and enjoy a diet of crustaceans and mollusks. These fish have strong teeth, that easily chomp through the shells of mussels, crabs, small lobsters, and barnacles!


The Tautog (Tautoga onitis) is found in coastal oceans often around jetties and shipwrecks from Nova Scotia to South Carolina.  They can grow to be about 24 inches (61 cm) long. Their diet consists of crustaceans and mollusks. The blunt head is more prominent in males, with a pronounced white chin and a distinctive white spot on their side. They are often confused with cunner fish.


The Pumpkinseed (Lepomis gibbosus) can be found in ponds and lakes from Nova Scotia to Georgia. They grow to be about 8 inch (20 cm) long.  Their diet includes insects, snails, and small fish. The breeding males are known to display bright colors. Pumpkinseeds provide a valuable service to us by helping to control the mosquito population by eating their larvae.


The Spotted Turtle (Clemmys guttata) are found in wetlands, marshes, ponds, and streams from southern Maine to northern Florida. Their shells are about 5 inches (13 cm) long. They enjoy a varied diet that includes: worms, slugs, spiders, snails, aquatic vegetation, green algae, and insect larvae. This turtle is easy to identify by its yellow and orange spots on its shell and the top of its head.


Black Sea Bass (Centropristis striata) are found in coastal oceans from Massachusetts to northern Florida. The grow to be about 24 inches (61cm) in length. They eat a diet of shrimp, crabs, mollusk, squid, and other fish. They are not found in estuaries like striped bass. In Cape waters they are most often seen around piers, jetties, and shipwrecks!


Winter Flounder (Pleuronectes americanus) are found in coastal oceans especially in sandy bottoms from Labrador to Georgia. They grow to be 22 inches (56cm) and eat a diet of worms, shrimp, and mollusks. They are great at camouflage! There are two flounder in today's picture can you find them both? 


Lobsters (Homarus americanus) are found in coastal estuaries to off shore depths from Labrador, Canada to North Carolina. They enjoy a varied diet of seaweed, crabs, sea urchins, marine invertebrates, fish, and dead marine life. Lobsters are typical a green color but genetic variations can cause rainbow of colors from white to blue! This orange color is referred to as a pumpkin lobster and is only found in 1 in 4 million lobsters!


The Clearnose Skate (Rala eglanteria) is found in shallow ocean waters from Cape Cod to Florida. They can grow to be a 33 inches (84 cm) long and 18 inches (46 cm) wide. Their diet consists of mollusks, shrip, crabs, worms, and small fish. They are excellent at camaflouge and will burry themselves in the sand so only their eyes are showing!  We recently had a clearnose skate hatch in our tidepool!


Sea Ravens (Hemitripterus americanus) are found off shore is rocky areas from Labrador to Chesapeake Bay. They can grow to 20 inches (51cm) on a diet of clams, lobster, fish, squid, shrimp, sea urchins, and sand dollars. They can exhibit an amazing range of colors including deep red, dark brown, purple, and various shades of yellow. Our Sea Raven measures just over 12 inches and yet can completely disappear! It can sit totally motionless and is camouflaged like rocks and plants.


The Lined Sea Horse are found in coastal oceans especially in eel grass from Nova Scotia to the Gulf of Mexico. They cling to the eel grass with their monkey-like prehensile tails. They are about 6 inches (15cm) long and feed on tiny crustaceans. After the female deposits eggs in the male's abdominal pouch, the male will give birth to the young!


The Bluegill (Lepomis macrochirus) is found in streams ponds and lakes from Massachusetts to northern Mexico. On a diet of insects, crayfish, and fish they can grown to be 9 inches (23cm) long. After the female bluegill lays eggs in a crater-like nest, the male fiercely defends it until the fry hatch.


The Northern Pipefish (Syngnathus fuscus) is found in coastal oceans, especially in eel grass from southern Canada to northern Florida. These relatives of the seahorse grow to be from 4 to 6 inches (10 to 15cm). They use their small mouth at the end of their tubular snout to eat small crustaceans called amphipods. They can independently move their eyeballs and their bony structure makes them unappealing to fish eating predators.


The Horseshoe Crab (Limulus polyphemus) is found in coastal oceans (especially estuaries) from the Gulf of Maine to the Gulf of Mexico. Their favorite food include molusks and worms. Females can grow 24 inches (61cm) in length but males are smaller. Horseshoe Crabs are not true crabs, but arthropods and are more closely related to spiders and have been on earth for 450 million years!


The Yellow Perch (Perca flavescens) are found in quite streams, freshwater ponds and lakes from Hudson Bay, Canada to South Carolina. Perch grow to be about 10 inches (25cm) and enjoy eating plankton, insects, and fish. If you have been fishing at a pond on Cape Cod you may have caught one of these fish. They hover in the water column between submerged plants and their veritcal stripes provide camouflage.


The Common Snapping Turtle (Chelydra serpentina) are found from Southern Canada to the Gulf of Mexico and west to the Rocky Mountains in any permanent body of fresh water. Their shells can grow to be 18 inches (46cm)! Their diet include plants, invertebrates, small fish, birds, mammals, and decaying animals. Snapping Turtles do not pose a threat to people in the water, on land however, they will stand their ground and defend themselves with a long neck and powerful jaws!


The Large Mouth Bass (Micropterus salmoides) grow to be about 18 inch (46cm) and are found in streams, rivers, ponds, and lakes from Southern Canada to the Southern United States. They enjoy a diet of insects, crayfish, and fish. The Large Mouth Bass was originally found in the Mississippi River system and South Eastern United States. It was introduced to other areas as a game fish and quickly became a dominant predator. As such, native trout and salmon fisheries have declined.


Our Eastern Painted Turtles (Chrysemys picta picta) grow to be about 6 inches (15cm) and can be found from Nova Scotia to Georgia in quite streams, ponds, and lakes. Their diet includes plants, insects (including mosquito larvae!), snails, and crayfish. The top shell (carapace) and bottom shell (plastron), limbs, and head of this semi-aquatic "pond" turtles are all brightly colored. The male has especially long claws on its front feet, which it uses for its remarkable mating dance.


Our Wood Frogs (Lithobates sylvaticus) grow to be about 3.25 inches (8.2 cm) and can be found from Alaska and Canada to the Appalachians in moist woodlands, swamps, ravines, and bogs. They enjoy a diet beetles, flies, worms, and other invertebrates. Wood Frogs can freeze like popsicles during the wintertime. Inside the frogs cells, there is a thick sugary-type syrup. They are freeze-tolerant and can survive the process of freezing, thawing, and freezing again.


The shell of the Sea Scallop (Placopecten magellanicus) can grow up to about 8 inches (20cm).  You probably haven't seen one of these while walking the beach.  They are not found near shore but rather in deeper waters. You may have eaten one of these. In the United States we only eat the adductor muscle (the smooth round white part) while in different parts of the world, the entire animal is eaten like we do with oysters.


The Northern Anemone (Urticina felina) can grow up to 5" (13cm) in diameter. They are found from the Arctic to Cape Cod, typically on the lower shore and particularly on shores exposed to strong wave action. They attach to rocks and boulders and are often found crowding together at the bottom of pools forming dense carpets. They get their nutrients from whatever the waves wash over them.

Northern Anemone


The Eastern Milk Snake (Lampropeltis triangulum) are about 6 inches when they hatch and grow to be about 24-36 inches (61-90cm) but have been known to be longer. Their diet consists of mice and other small rodents. They are found from Southern Canada to North Carolina. You may have had a hard time seeing the Milk Snake if you visited the Museum, these snakes like to burrow and hide and can often be found underneath rocks and logs. Just like all snakes found on Cape Cod, the Eastern Milk Snake is not venomous.

Milk Snake


The Northern Red Bellied Cooter (Pseudemys rubriventris bangsi) is Federally Endangered. Here at the Museum we are head-starting these two in cooperation with MA Fish and Wildlife.  In the wild Cooters eat plants such as water lilies, arrowhead and other aquatic plants. Here at the Museum they enjoy a diet of lettuce. When we receive them in September 2019, they weighed 10 grams and were the size of a quarter. We hope they will be about 700 grams when we release them at the end of May. They grow to be about a foot long (30cm) and weigh about 6 pounds (2,721 grams). They will be released in a conservation area in Plymouth. This is the only area in New England with Northern Red Bellied Cooters. There are approximately 1,000 cooter at this time.

Northern Red Bellied Cooters


The Musk Turtle (Sternotherus odoratus) is about 4 inches (10cm) long. It can be found in ponds, streams, rivers, and lakes from southern Canada all the way to Texas! Its diet includes plants, insects, snails, and crayfish. The Musk Turtle is an excellent climber (special precautions have to be taken at the Museum for this Houdini).  It is often referred to as the "stinkpot" due to the natural musky odor it releases.

Musk Turtle


Our Common Sea Star (Asterias forbesi)! These echinoderms can grow to have a radius of 5 inches (13cm) and are found along the ocean bottom (especially on rocky bottoms) from Massachusetts to Florida. Their favorite food is clams and other bivalves. To eat, a sea star will push its stomach out through its mouth and into the shell of its food and digest it in its prey's shell! If a sea star looses an arm, it can regenerate an new one!

Sea Star


Our Ocean Pout (Zoarces americanus)! This "eel like fish" can grow up to 39 inches (98cm) long. Behind their pouty lips, they have two rows of strong teeth that they use to eat mollusks, crustaceans and some fish. These bottom dweller can be found in waters from Labrador to Delaware and has anti-freeze proteins in its blood so it can survive in near freezing temperatures!

Ocean Pout


This is our Oyster Toadfish (Opsanus tau). They are about 12 inches (29cm) long and like to eat worms, clams, crustaceans and small fish. They can be found on the ocean floor in coastal waters from Cape Cod to Florida. Male Oyster Toadfish will build a nest among shells and rocks for the female to deposit her eggs in. After the female lays her eggs, the male will defend the nest until the eggs hatch (about 3 weeks).

Oyster Toad Fish

The Aquarium exhibit graphics were made possible by the generosity of the BILEZIKIAN FAMILY FOUNDATION.