Posts Tagged 'shark'

Built for Speed: How Our Fastest Fish Friends Keep Their Pace

Whether it’s racing down Pratt Street or pulsing through the open ocean on the hunt for dinner, reaching maximum speed is all about physics. Above ground, vehicles have an initial thrust from the motor to propel them forward. To build speed, the exterior of cars are designed to be as aerodynamic as possible, meaning they minimize drag and friction to not overexert the engine.

Although the Indy Cars expected at the Grand Prix of Baltimore this weekend can reach speeds of up to 230 mph, they are no match for jet engines! It’s hard to believe that all that weight and metal can soar through the air at speeds exceeding 2,000 mph. Getting a jet off the ground involves three major factors: (1) the engine provides thrust; (2) the wings provide lift to counter gravity; and (3) the aerodynamic shape cuts friction and drag.

These principles also apply to sharks and our other fast fish friends that live in the open ocean. The caudal (tail) fin provides initial thrust by swaying back and forth, pushing the water and propelling the animals forward. Like the wings of an airplane, the pectoral (side) fins give the animals the needed lift to keep them moving and counter gravity. And their smooth, streamlined bodies reduce as much friction and drag as possible!

One of our sand tiger sharks showing off its streamlined body

Sand tiger sharks are built for continuous swimming. They feed primarily on fish and need to be able to move quickly. Their big caudal fins help push them forward through the water all day without exhausting their energy. Their horizontal pectoral fins give the sharks the perfect shape to lift and stay above the ocean bottom. The pectoral fins are also critical to helping them get water over their gills so they can breathe. Unlike fish species, sharks don’t have swim bladders to keep them afloat, so it takes a lot more work to fight the drag of water molecules!

A sand tiger shark stays afloat thanks to its large pectoral (side) fins

Over time, humans have adapted to swim, and in the case of Olympian Michael Phelps, pretty quickly, but we are in no way built for it. We don’t have webbed feet, fins, or a streamlined body made for the water. Phelps, who holds the fastest swimming speed record, maxes out at just under 5 mph. Sharks, on the other hand, can hurdle toward prey at recorded swimming speeds of up to 46 mph!

Animal Updates – April 13

Between our Baltimore and Washington, DC, venues, more than 17,500 animals representing 900 species call the National Aquarium home. There are constant changes, additions, and more going on behind the scenes that our guests may not notice during their visit. We want to share these fun updates with our community so we’re bringing them to you in our weekly Animal Update posts!

Check our WATERlog blog every Friday to find out what’s going on… here’s what’s new this week!

Baby Spotted Lagoon Jellies
Mastigias papua 

Our jellies lab welcomed a special delivery from the Oklahoma Aquarium: baby lagoons! They’re about a month and a half old right now, and we’ve never had this species this young before. Right now, they’re developing and growing in our jellies lab, and once they reach about four or five months old they’ll be big enough to go on exhibit.

Baby lagoon jelly

Right now they look just like tiny blue blubber jellies, but as they grow, they’ll develop spots and lose their bluish tint. Since they arrived, they’ve already started to sprout tentacles, and spots are appearing along the edges of the bells.

Jelly's first tentacle!

Quite a bit goes into giving these jellies what they need to grow and thrive. They have a high metabolism, so they’re fed at least three times a day, sometimes more. These sun-loving jellies are kept under a special metal halide light, which is a different spectrum than regular lights. Spotted lagoon jellies have a symbiotic relationship with the algae that live in them; the algae need the light to photosynthesize, and the jellies eat the waste products the algae make in the process.

Older spotted lagoon jelly

Breeding Season for Sand Tiger Sharks
Carcharias taurus
You may see staff members observing and monitoring the behavior of the sand tiger sharks in our Open Ocean exhibit. It’s breeding season for these sharks, and sometimes the males can get a bit aggressive.

Sand tiger shark

Did you know? Female sand tiger sharks do not have the expected single uterus – each female has two, and babies develop in both at the same time. In each separate uterus, the unborn pups eat each other and devour any still-unfertilized eggs until only one remains. Eventually one baby is born from each uterus – talk about survival of the fittest!

Be sure to check back every Friday to find out what’s happening!

Maryland: Help save the sharks!

Shark populations worldwide are in danger of collapse due to fishing pressures stimulated by the global demand for shark fin soup.  Every year fins from tens of millions of sharks are used for this traditional, but non-nutritional meal.  Many species have been depleted nearly to the brink of extinction.  The National Aquarium and its partners are advocating on behalf of legislation that will help eliminate the market for shark fins in Maryland.

Current Federal and Maryland laws banning shark finning control shark handling practices but do not restrict the number of sharks killed just for their fins, or the substantial market for shark fins which creates economic incentives to overfish sharks just for their fins.  One of the most effective ways to protect sharks is to eliminate the market for fins by prohibiting their sale.  California, Hawaii, Oregon and Washington have all banned the possession, sale, trade and distribution of shark fins, and now it’s our opportunity to lead.

With our support, the Maryland State Senate has passed the bill (Senate Bill 465) that would ban the possession or distribution of shark fins in the state.  Now, it will be heard in the House of Delegates.  This legislation will establish Maryland as the first state on the east coast to join these other states in ensuring we are not contributing to the supply and demand of shark fins.

What You Can Do!
If you live in Maryland, please contact your delegates and let them know you support the “Shark Fin Ban” bill.  They need to hear from you!

Thoughtful Thursdays: Save the Sharks!

Many people think of sharks as frightening, sharp-toothed predators, far from being in need of our protection. In fact, people are more inclined to believe that we humans need protecting from these creatures. This couldn’t be farther from the truth: shark populations worldwide are in danger of collapse due to fishing pressures stimulated by the global demand for shark fin soup.

Every year, fins from tens of millions of sharks are used for this traditional, non-nutritional meal. Many species have been depleted nearly to the brink of extinction. As predators at or near the top of marine food webs, sharks help maintain the balance of marine life in our oceans.

Shark populations must be protected from the practice of overfishing. The National Aquarium and its partners, including the National Wildlife Federation and Oceana, are advocating on behalf of legislation that will close loopholes in current legislation that bans shark finning. We welcome your support!

Why Sharks Need Our Help

Unlike many fish species, sharks are slow to mature and have very few offspring, making them vulnerable to overexploitation. The sandbar and sand tiger sharks are two species in our mid-Atlantic waters that have faced great fishing pressure. 

Sandbar shark

Sandbar Shark at the National Aquarium


The sandbar shark, which utilizes Delaware Bay as a pupping ground, can take up to 14 years to mature, has a gestation of 11–12 months, and gives birth to 6–10 pups. The females breed only every other year. These young sandbar sharks are closely tied to the health of the marine ecosystem.

Research shows that the massive depletion of sharks has cascading effects throughout the ocean’s ecosystems. In Maryland, the depletion of sharks has caused an increase in cownose rays in the Chesapeake Bay, which threaten the oyster industry.

In the 30 years the National Aquarium, Baltimore, has been open, sharks have gone from a commercial fishery the federal government declared underutilized to the brink of extinction. In that time, hammerhead shark populations in the Atlantic have decreased by nearly 93%. Since 1986, all recorded shark populations in the northwestern Atlantic, with the exception of mako sharks, have declined by more than 50%.

Scientists warn that continual overfishing of sharks has decimated the population, which continues to dwindle and cannot sustain the current rates. The International Union for Conservation of Nature Red List of Threatened Species estimates that 30% of open ocean sharks are threatened with extinction.

What We Can Do

Recently, the National Aquarium took a stand to support the 2010 Shark Conservation Act, but we need to do more. Current federal and Maryland laws banning shark finning control shark handling practices, but do not restrict the number of sharks killed just for their fins, or the substantial market for shark fins that creates economic incentives to overfish sharks for their fins.

One of the most effective ways to protect sharks is to eliminate the market for fins by prohibiting their sale. California, Hawaii, Oregon, and Washington have all banned the possession, sale, trade, and distribution of shark fins, and now it’s our opportunity to lead.

With our support, the Maryland Legislature has introduced bills (Senate Bill 465 and House Bill 393) that would ban the possession or distribution of shark fins in the state. This legislation will establish Maryland as the first state on the East Coast ensuring we are not contributing to the supply and demand of shark fins.

The National Aquarium’s shark expert, Andy Dehart, will be testifying at both hearings in February, and the Aquarium’s Director of Conservation Laura Bankey and Director of Government Affairs Mark Yost are working closely with our partners to support the legislation as it moves through legislative channels.

What You Can Do

Let your state representatives know you care about sharks, and all the species in the marine ecosystem that depend on them! Our partners at Oceana have initiated an online advocacy campaign to support the shark fin ban in Maryland. Sign our letter today, and help save the sharks!

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!


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