A tale of two sand tiger sharks

We’re very excited to welcome two new sand tiger sharks to the Open Ocean exhibit at the National Aquarium, Baltimore.

Where did these sharks come from, and how did they get to the Aquarium? Watch this video to find out:

Whenever possible, the animals in our exhibits are bred right here at the National Aquarium, or at other zoos and aquariums across the country. The National Aquarium has successfully bred many species of cartilaginous fish, including Southern stingrays and cownose rays. Breeding programs reduce the need to collect animals from the wild.

Did you know? The Association of Zoos and Aquariums (AZA) maintains a forum where accredited institutions can swap animals—it’s like Craigslist for aquariums!

Breeding programs are not possible for some species, including the sand tiger shark, due to intensive resource requirements and logistical impossibilities.

For this reason, Andy Dehart, director of Fishes & Aquatic Invertebrates for the National Aquarium and renowned shark expert, and his team are leading the way for sustainable shark-collecting practices that put the safety and health of the animals first.

Sharks are collected using a long-line fishing technique that minimizes bycatch, or fish caught unintentionally, and “we modify our fishing hooks, sanding off the barbs, to reduce injury and handling time of the sharks,” says Andy. “We know that line fishing with barbless hooks means we catch less sharks, but that’s a trade off we’re happy to accept,” he continues.

The sharks are transported back to shore in a special shark-sized fish box on the Aquarium’s shark collecting vessel. If a shark is thrashing in the fish box, Dehart and other Aquarium staff will actually get in the box and “hug” the shark to keep it still to prevent any injury.

A big, cold, wet shark hug—now that’s dedication!

New parents for a shark

The new school year has just begun, and this first-grade class has already done something amazing: they raised the money to adopt a shark from the Aquarium!

From Mrs. Detter, the teacher:

“While reading a book about endangered animals, the children expressed their interest in adopting an animal from a nearby zoo or aquarium. After many voting sessions, the children decided to adopt a shark from the National Aquarium. To make this possible, we need to raise $50.”

This is how we are tracking our progress.

It didn’t take these dedicated first-graders long to raise the money needed to submit their adoption papers.

WE DID IT!!!

Congratulations, Mrs. Detter’s class! You should be receiving your Aquadopt package before long. We hope you come visit “your” adopted shark sometime soon! All the information you need for planning a great field trip is at aqua.org/teachers. In the meantime, here are some fun shark facts for you:

•  Baby sharks are called pups.
• The sand tiger shark adjusts its buoyancy by burping—gulping and expelling air at the surface. This allows the shark to hover nearly motionless in the water.
• The largest fish in the world is the whale shark, which can grow up to 41 feet long. And whale sharks have no teeth!
• Sharks have no bones at all. Their skeletons are made of cartilage. Feel your ears and the end of your nose. Notice how they’re kind of squishy, not bony? That’s cartilage!
• Any of you have a loose tooth? A shark may lose up to 1,000 teeth a year, or 30,000 teeth in a lifetime! Shark teeth are constantly replaced as they wear or break. The inside of a shark’s jaw has five to 15 rows of teeth that usually lie flat until the tooth in front of it falls out. When a tooth is lost, another rotates forward to replace it, usually within 24 to 48 hours. The process of tooth replacement in sharks is very similar to the movement of a conveyor belt or the steps on an escalator.

Look at those rows of teeth!

• The skin of a shark is covered in tiny scales or skin teeth called dermal denticles. These skin teeth point toward a shark’s tail, so a shark feels smooth if touched from head to tail but feels like sandpaper if felt from tail to head.
• There are approximately 400 species of sharks in the world. At the National Aquarium, we have eight different species, including bonnethead sharks, nurse sharks, zebra sharks, sawtooth sharks, and sand tiger sharks.

Bonnethead shark

Meet Zeke, the newest addition to our Wings in the Water exhibit!

Zoe the zebra shark—a long-time icon at the National Aquarium, Baltimore—now has a companion in our Wings in the Water exhibit!

Last week, we added a young male zebra shark to the tank. At about 4 feet long, the male zebra shark—named Zeke—is much smaller than Zoe, and he is also much lighter in color.
Zoe has been at the Aquarium for 12 years, and is estimated to be about 17 years old. Zeke is 2 years old.

Zeke the zebra shark

Zebra sharks are so named because as juveniles, these sharks have dark bodies with yellowish stripes. As the sharks grow, the stripes break up and the pattern changes to dark spots on a grayish-tan background. Because of this change, zebra sharks are often referred to as leopard sharks.

Two more features make this shark difficult to confuse with any other: the prominent ridges running the length of the body and the impressive tail, which is nearly as long as the body itself.

Zeke has mostly lost his stripes, but you can see that his spots are much closer together than Zoe’s. He came to the Aquarium as a small pup in August 2010. Since then, Aquarium staff has cared for Zeke behind the scenes, and prepared him for introduction into the exhibit.

Part of that preparation included training Zeke to take fish from the end of a pole held at the surface of the water by Aquarium staff. For the safety of our animals and staff, the sharks at the Aquarium are always pole fed, not hand fed, by the divers.

Zeke is adapting and responding very well to his new environment. Be sure to look for Zeke the next time you visit!

30 fascinating fish facts

2011 marks the National Aquarium’s 30th anniversary year—a year that will honor the Aquarium’s successful past and highlight its future as a leader in global conservation and aquatic health. Turning 30 also gives us an excuse to celebrate, have fun, and create this list of 30 fascinating fish facts for your cerebral pleasure!

1. Fish are cold-blooded, which means their internal body temperature changes as the surrounding temperature changes.

2. About 96% of fish are bony fish. The rest are cartilaginous fish, like sharks, skates, and rays.

Electric eel

3. Electric eels can discharge up to 550 volts, using their shock as an offense for catching food or a defense to escape.

4. Only the front 1/5 of an electric eel contains vital organs. These are located directly behind its head. The rest of the body is comprised of organs that produce electricity.

5. Arowana have the ability to jump out of the water to catch prey such as insects, birds, and bats.

6. More species of fish are found in the Amazon River than in all of Europe.

7. Gar are known as “living fossils,” as their remains have been found dating back to the Cretaceous period.

8. The female seahorse transfers the eggs to the male’s pouch, where they are incubated until birth.

Red lionfish

9. Red lionfish are beautiful in the aquarium, but potentially devastating to the Atlantic Ocean, as the first successfully invasive species.

10. The northern snakehead has the ability to gulp air and absorb oxygen through a modified swim bladder that functions much like a lung. This ability allows the snakehead to travel across land to move into new bodies of water.

11. Piranhas hunt in large groups called shoals, or packs.

12. The largest fish in the world is the whale shark, which can grow up to 41 feet long.

13. Baby sharks are called pups.

14. The sand tiger shark is the only shark known to adjust its buoyancy by burping—gulping and expelling air at the surface. This strategy allows the shark to hover nearly motionless in the water column.

Seven-spot archerfish

15. The archerfish is named for its peculiar adaptation of shooting a stream of water like an arrow at its unsuspecting prey—a tasty insect perched on a branch above the water.

16. The male banggai cardinalfish incubates the eggs in his mouth and continues to hold the young within his mouth cavity after hatching to further protect them.

17. Feather blennies lay their eggs in empty oyster shells. These territorial predators use their strong jaws to snap up and eat small fish and crustaceans that venture too close to the oyster shells.

18. The green moray eel is really brown! The yellow tint of the mucus that covers its body, in combination with the drab background color, gives the fish its characteristic uniform green color.

19. Southern stingrays have a “live birth,” meaning that the eggs hatch within the mother’s body. The pups, up to 10 in a litter, average 9 inches across at birth. Before their live birth, stingrays’ “wings” are curled up like crepes.

20. Burrfish are covered with short, heavy spines that are always erect, unlike their cousins the porcupinefish, which have movable spines.

Porcupine fish

21. When feeling threatened, pufferfish quickly ingest water to inflate their bodies into a ball several times their normal size.

22. Flounders and sole are fish with both eyes on the same side of their head. One eye actually migrates to the other side during larval development. Like most flatfishes, these bottom-dwellers can change the color patterns on their skin to blend in with their environment. They bury themselves in the sand and, with both eyes facing up, wait to ambush unsuspecting prey.

23. Jellies have been around for more than 500 million years—they pre-date dinosaurs!

24. The lined seahorse is the only seahorse found in the Chesapeake Bay. It camouflages itself by developing leafy appendages and changing colors.

Clownfish

25. In a group of clownfish, there is a strict dominance hierarchy. The largest and most aggressive female is found at the top.

26. Clownfish and sea anemones have a symbiotic relationship. The sea anemone protects the clownfish from predators, as well as providing food through the scraps left from the anemone’s meals. In return, the clownfish defends the anemone from its predators and cleans it from parasites.

27. Some catfish create saucer-shaped nests by fanning the river or lake bottom with their tails. Several thousand eggs are deposited in the nest and are guarded until they hatch.

28. The toothless catfish is not really toothless. It has teeth in the back of its mouth. This bottom-feeder vacuums through the sand to find its food.

29. The Australia grunter fish is so named because it emits an audible grunting sound when handled out of the water.

Barramundi

30. Barramundi, a giant perch found in Australia, changes sex as it grows up, starting as a male. Upon reaching 19.7 inches in length, it become female. These fish can grow to up to 6.5 feet long!

New shark pups!

Baby swell sharks have begun to hatch at the National Aquarium in DC. This year the aquarists were watching over six fertilized eggs, and three have hatched this summer. The fourth and fifth are expected shortly, and the sixth still has a few months of gestation.

The picture to the right shows the latest three in their isolation basket. The swell shark is so-named because it pumps water into its stomach, causing its body to swell up. It is nocturnal, and grows to approximately three feet.

Be sure to visit www.nationalaquarium.com to learn more about all of the fascinating creatures living at the National Aquarium in DC!