Virginia Living Museum
Sharks

  
Sharks belong to a very successful and diverse group collectively known as elasmobranches, cartilaginous fishes whose ancestry dates back nearly 400 million years. The Virginia Living Museum houses several interesting species of sharks, skates and rays that each represents a unique environment.

Sharks are highly successful apex predators – meaning that they are at the top of the food chain - and have few natural predators, except for humans. However, humans now play a large role in the survival of sharks and fishes worldwide; sharks are particularly vulnerable to over-fishing because of their reproductive strategy. As with most large animals, sharks reach maturity much later than most fishes, usually 8 -10 years and therefore must survive much longer to simply get the chance to reproduce. Additionally, sharks produce few young and carry them for a long time; these factors, as well as their desirability in some parts of the world as a food fish and their overall negative perception has made their future tenuous.

In our Chesapeake Bay Aquarium, we display two species of sharks, a sandbar shark (Carcharhinus plumbeus) sometimes referred to as a brown shark, and a pair of nurse sharks (Ginglymostoma cirratum). Sandbar sharks are a member of the Family Carcharhinidae more commonly called requiem sharks. Sandbar sharks like all requiem sharks are very active predators and strong swimmers, feeding primarily in low light conditions upon bottom dwelling creatures, such as crabs, squid, mantis shrimp, spot, croaker, and even skates and rays. These handsome sharks may reach 6 to 8 feet in length and live over twenty years. Our shark is a juvenile male estimated at approximately 5 years of age and was captured over two years ago near the mouth of the York River. He has been trained to accept food offered on long tongs by the aquarium staff. His diet in captivity is as similar as possible to that in the wild: squid, shrimp, herring, spot, seatrout, and nutritional supplements. 

The two nurse sharks represent a species rarely found in the bay itself. Generally considered a warm-water species, nurse sharks are a sedentary species often laying on the bottom during the daylight hours and hunting at night. Nurse sharks like all sharks have an excellent sense of smell, but unlike other sharks have two fleshy barbels at the corners of their mouth. When hunting, nurse sharks often scour the bottom using their barbels to taste for invertebrates or unsuspecting fishes, which they suck in with an extremely powerful intake of water. The nurse sharks in the Chesapeake Bay Aquarium were donated by their owner after they became too large to keep. We have one female and one male; male sharks possess a pair of claspers, two fleshy mating appendages located at the base of the pelvic fins. Both the nurse sharks are voracious eaters and their diet, which is nearly identical to the sandbar’s diet, has to be closely monitored so they do not become obese as they are inactive most of the time.

The third species of shark at the VLM is the chain dogfish Scyliorhinus retifer. This small species is named for the dark brown to black chain-like markings on an over-all tan colored body. Chain dogfish are common in Virginia waters, but prefer depths greater than 200’ so are rarely encountered except when taken as by-catch in the winter trawl fishery. Chain dogfish do not exceed 18 inches though they may live over twenty years. Because we keep them at a relatively cool 55° F and they are not very active, these small sharks consume only a few grams of food each week; they prefer squid and shrimp, but also are fed herring and trout fillet, clams, and scallops. To ensure each shark receives food, they are fed by impaling food on the end of a pole and placing the food directly in front of each shark. The staff notes if one or more do not eat.

Help pay for the food and care of the sharks at the Virginia Living Museum by adopting one today.