FAQ: Touching Sharks and Rays

The Trust Family Foundation Shark and Ray Touch Tank is one of our most popular exhibits – and with good reason! In this beautiful space, you get the chance to touch some of the world’s most fascinating animals – stingrays and sharks. To prepare you for your visit, here are some Frequently Asked Questions:

How do I get to the Shark and Ray Touch Tank?
The touch tank, two additional viewing tanks and the jellies exhibit are in the Aquarium’s West Wing. Reach the West Wing from the lobby, directly next to the restrooms and lockers. 

 
 Photo: J. Correa

What is the best time to be there?
If you are planning to visit during school vacation time, be prepared for the touch tank area to be busy. First thing in the morning (the exhibit opens at 9:30 most days) is the best time to be there. If you can’t do that, the end of our day (check the website for closing times) tends to be quieter.


Photo: J. Correa

Stingrays? Won’t they sting me?
Nope! Our rays have all had their stinging barbs clipped, just like you might clip the nails on a cat or a dog. The barbs grow back, and are clipped again before they have a chance to get big enough to be a problem.  Also, rays generally only sting if they feel that their lives are in danger.


Photo: S. Cheng

Sharks! Won’t they bite me?
Even though sharks have a bad reputation, they are not into biting people. Our sharks, like most sharks, are small, shy animals. In fact, you may not even see them when you first get to the exhibit. They like to hide.

What’s the best way to touch them?
Roll up your sleeves. Make a flat hand, like you’re giving a high-five. Place that flat hand into the water, with the water somewhere between your wrist and your elbow. Be still and quiet – rays and sharks can hear you, and can feel your movement, and they will get scared away if you are too loud or move too much. When they come near, you may gently reach down and pet them on their backs.

We hope to see you soon at the Trust Family Foundation Shark and Ray Touch Tank!

Sharks in Residence

Next week is December school vacation, so the Aquarium will be filled with families! However, the week before the holidays is pretty quiet, making it a great time to visit. One of the many benefits of coming to the Aquarium when it isn't extremely busy is that you can spend more time looking at the exhibits and closely observing the many inhabitants. And one of the best exhibits to take a closer look? The Trust Family Foundation Shark and Ray Touch Tank!

Two animals that get overlooked during the hubbub of the summer are the whitespotted bamboo shark (Chiloscyllium plagiosum - previously mentioned in this post) and the brownbanded bamboo shark (Chiloscyllium punctatum). Both species tend to rest and hide throughout the day, making them less likely to be seen during the course of a visit.


Brownbanded bamboo sharks have very faint light and dark brown stripes

Whitespotted bamboo sharks have dark stripes and white spots

Both species of bamboo sharks are benthic-type sharks, spending much of their time on the sandy bottom. To prevent being bothered by other animals (or predators) the sharks will find hiding places in which to rest. Coral reef overhangs or mangrove roots provide great cover and allow the sharks to rest in peace and quiet. And as our exhibit has lots of overhangs and roots, our exhibit animals take full advantage of these spaces!

Some of the many mangroves in the exhibit-can you find the sharks?

So next time you are at the shark and ray touch tank, take a peek under the coral pieces that dot the exhibit or among the roots of the mangrove trees. You may just spot a shark resting on the sandy bottom.

Resting on the sand



In the mangrove roots

A behind the scenes look at jellies

One of the oldest groups of animals alive today, jellies often appear elegantly simple to the casual observer. But spend a little time with one of our jelly lab aquarists and you get the impression that, when it comes to jellies, there is a lot more to them than many people suspect.

Here at the New England Aquarium, we frequently have a dozen or more species of jellies (like the moon jelly). Some are on exhibit for visitors to see while others are raised behind the scenes to be sent to other aquariums all over the world.

 
Younger lagoon jellies (Mastigias papua) contain photosynthetic algae. As they mature, they need less light and loose their bluish color.

In order to successfully raise jellies, our aquarists must be familiar with their unusual reproduction strategy. Like something out of a science-fiction film, jellies go through several life stages that are drastically different from one another. Adult jellies, called medusa, can reproduce sexually by releasing eggs and sperm. Fertilized eggs become free-swimming planula larvae.




The lifecycle of a local species, the moon jelly, is so complicated that it helps to have an illustration courtesy of Senior Aquarium Educator Lisbeth Bornhofft.

Jellies can also reproduce asexually by forming anemone-like polyps (jellies and sea anemones, along with corals, are related to each other) that strobilate, or bud off, identical copies of themselves. These free-swimming “buds” are called ephyra. In some species, several ephyra can bud off of one single polyp.Since the jelly lifecycle in the wild is seasonal, our aquarists recreate a temperature shift from winter to spring, or spring to summer, to cause the polyps to strobilate.

Thumbnail-sized ephyra of purple-striped jellies (Chrysaora colorata)

Some ephyra are photosynthetic; they have symbiotic algae called zooxanthaellae that converts sunlight into food. Other ephyra are quite content to munch on tiny brine shrimp. Feeding and growing, they will eventually “bell over” into an adult medusa. This is when the shape of the jelly changes from a pointy star to more of a solid dome.


Despite their small size, these ephyra are already predators. If you look closely, you can see the brine shrimp we raise and feed to our jellies.

Here at the Aquarium, we have jellies on exhibit in both the Thinking Gallery and in the West Wing. While most of the jelly raising happens behind the scenes, we currently have Cassiopia jellies reproducing in the live mangrove exhibit. These jellies are often referred to as “upside-down” jellies since as adults they settle to the bottom of shallow, sunny tropical waters and use their bell like a suction cup. Being upside-down allows the photosynthetic algae to get plenty of sun!


Below is a video of both adult and ephyra stages of Cassiopia on exhibit. Or better yet, come to the New England Aquarium and see them for yourself!

-Dave

New Leopard Ray in the Touch Tank

Visitors to The Trust Family Foundation Shark and Ray Touch Tank this weekend may notice a stunning new arrival. Here's Ashley, one of our educators, to tell you a little about the newest addition.



Learn more about leopard whiptail stingrays in this previous blog post. With excellent weather expected for the long weekend ahead, make the most of it with a trip to the Aquarium to meet these beautiful creatures!

Turtles Get a Head Start

Our blog followers are well aware of our efforts to rescue and rehabilitate sea turtles each fall. Behind the scenes at the Aquarium, some unique species of fresh water turtles are also getting a leg up. The long-running head start program helps native turtles by growing tiny hatchlings in the safety of an aquarium over the winter until they're big enough to fend for themselves in the wild come the spring.




Recently, the Aquarium welcomed the newest generation of the northern red-bellied cooters into the head-start program. As you can see in this video, they are only the size of a silver dollar right now.



These little guys will grow big and strong on a diet of lettuce and occasional protein pellets over the next eight months. When they're released next May, they will be about the size of a grapefruit. It would take two years for turtles in the wild to reach that size! In the meantime, these turtles will join the troupe of animals seen during Live Animal Presentations just as soon as they're big enough.

Not to be confused with red-eared sliders or painted turtles, red-bellied cooters are found in the mid-Atlantic states from New Jersey through North Carolina. They are also found in a small pocket of Massachusetts near Plymouth, although this population faces formidable threats due to habitat loss. About 30 years ago, there were estimated to be only about 300 animals left. However, with the help of U.S. Fish and Wildlife and many other local institutions, the Aquarium has been helping to raise red-bellied cooters as part of this head start program. There are an estimated 3,000 turtles today!



So if you're out and about exploring freshwater habitats near Plymouth, keep an eye out for a northern red-bellied cooter. That turtle could have been raised right here at the Aquarium!

LAP: Eastern Box Turtle, Part II

This is the second post about the newest animals to appear during the Aquarium's Live Animal Presentations. Get up to speed on Eastern box turtles in this previous post.

Road separating habitat
Although they have a variety of habitats, box turtles greatest threat is habitat loss or fragmentation.


Eastern box turtle. Photo courtesy Jarek Tuszynski via Wikimedia Commons

Fragmentation occurs when habitats are separated by land that humans have developed. The fragmented habitats tend to be very small, resulting in a loss of biodiversity. When confined to smaller areas, turtles may have a difficult time finding food or mates and as a result may suffer from inbreeding and other genetic problems. Massachusetts alone loses about 40 acres of natural habitat per day to development (Mass Audubon Study from 2003).


Photo courtesy Tysto via Wikimedia Commons

Roads are one of the greatest dividers of habitats. Box turtles sometimes use less-than-ideal routes to avoid roads which may increase the risk of predation. Many female turtles looking for nesting habitat cross roads and are killed by cars, reducing the breeding population. One solution to the problem of habitat fragmentation is to link the fragments by preserving or planting corridors of native vegetation. In the case of roads, underground tunnels can be dug to connect habitats. Do you think this is a good
idea? Can you think of other solutions? Here are some more ideas to help turtles…

• Restore vegetation (like your yard) to a more natural state. Use native plants!
• Mow only in the hot afternoon, when turtles are less likely to be out
• Avoid using herbicides, especially on fruiting plants.
• Keep pets on leashes
• Protect habitat from development: contact the Wildlife Land Trust or Nature Conservancy to help purchase and preserve land where box turtles occur
• _______________ (insert your idea here!)
  

Reproduction
Box turtles reach sexual maturity at about 5 to 10 years old. In Massachusetts, females usually don’t lay their first clutch until 14 years of age. Females can store sperm for up to 4 years! They sometimes travel up to a mile to find suitable habitat and lay between three and six eggs each spring in a shallow nest. The eggs are left unguarded and hatch in summer to early fall. Over the span of one lifetime, females lay hundreds of eggs, but only two or three will survive to adulthood. These eventually replace their parents in the population. However if box turtles are removed from the wild, this reduces the breeding population, creating a decline in total population numbers.


Photo via Wikimedia Commons

Boy or Girl?

• Male box turtles have wider tails, more flattened shells, and dark orange or red eyes.
• Females box turtles have brown or light orange eyes.

Because box turtles are long-lived (30-50+ yr. lifespan), slow to mature, and have few offspring, their population is vulnerable to habitat disturbances, motorized vehicle kills, high levels of predation, and loss of individuals through the pet trade. Eastern box turtles are listed as a Species of Special Concern in Massachusetts and are protected from commercial trade under CITES (Convention on International Trade of Endangered Species of Wild Flora and Fauna).

They are also being protected by YOU, when you share what you've learned about these unique turtles and inspire stewardship. Good Job!

LAP: Eastern Box Turtle, Part I

This is the first of two posts about the newest animal to be featured during a Live Animal Presentation at the New England Aquarium. Learn more about LAPs, or Live Animal Presentations, in this behind-the-scenes post.

Behold the Eastern Box Turtle (Terrapene carolina carolina), our newest LAP animal! 

Eastern box turtle. Photo courtesy National Park Service via Wikimedia Commons

This type of turtle is one of only two species of box turtles found in the US (the other is called ornate or western box turtle) and it is also the most common terrestrial turtle found in the eastern half of the US. Box turtles are unique for their highly specialized super-duper protective shell. The plastron has a hinge that can close up like a door so that its legs, tail, head and neck can be safely tucked inside out of a predator’s reach.

Photo courtesy Doug Letterman via Wikimedia Commons

Predators
Box turtle predators include skunks, raccoons, minks, dogs, snakes and rodents. Although these turtles have the unique hinged protection the population of predators is booming, increasing the chance of turtle predation. Predators such as raccoons, skunks, and rodents are benefiting from the availability of additional food sources such as garbage, bird seed and pet food.

Diet
Box turtles have a varied diet including insects, worms, slugs, lizards, berries, vegetable matter and carrion. They can even eat mushrooms that are toxic to humans. In fact, some folks have been poisoned by eating the flesh of box turtles that consumed toxic mushrooms. These turtles are also famous for their impact on the germination of the may-apple plant. May-apple seeds ingested by turtles have about a 38% germination rate, whereas un-digested seeds only have an 8.5% success rate. Box turtles, which are the may-apple’s main seed distributors, are able to reduce the thickness of the seed coat allowing germination to take place more easily. The may-apple root is being studied to use as a possible treatment for cancer.

Photo courtesy U.S. Fish and Wildlife via Wikimedia Commons

Habitats Box turtles are often found in forests, fields, thickets, marsh edges and bogs. When they’re feeling adventurous, they sometimes travel to shallow water at the edge of ponds and streams. In the heat of the summer, these turtles will wedge themselves into the soil surface to help retain moisture while they rest. In winter, box turtles hibernate in loose soil at a depth of about 2 feet, or sometimes under leaf litter, stump holes or mammal burrows. Box turtles have developed a tolerance for freezing similar to wood frogs, where the liver production of glucose acts like antifreeze. They are capable of surviving gradual partial freezing for a few days, but a sudden cold snap could kill them.


There much more to learn about the Eastern box turtle, like some of the challenges they're facing in the wild and what you can do to help them. Stay tuned for Part II of LAP: Eastern Box Turtle!

The Schooling Exhibit: You're Getting Sleepy...

As you approach the shiny, moving wall of herring that inhabit the Schooling Exhibit in the Aquarium's Thinking Gallery, you may quickly find that it's pretty difficult to focus on just one fish at a time. In fact, that's exactly the point. Take a look:



It's an effect that can be almost hypnotic to watch. Here's a frozen frame that makes it possible to pick out individual fish:



Groups of schooling fish, like the blueback herring in this exhibit, can coordinate their movements to make themselves look like one big, shimmering blur. This makes it very hard for predators to pick out one particular fish and attempt to chase it down. So, often, all a predator can do is just to swim into the group, mouth open, and hope for the best--not the most effective, or energy-efficient, of tactics.

The adaptations that make schooling behavior possible are very interesting, and almost amount to a special sixth sense for these fish. Check back soon to learn more.

-Tim

LAP with a LOB?

One way that visitors can get up close and personal with an Aquarium animal is to attend a Live Animal Presentation—or as we educators abbreviate it to, a LAP. Interpreters bring an animal from behind the scenes, showcasing that animal during a formal talk. A myriad of animals get their moment in the spotlight-anything from jellies, horseshoe crabs, turtles, toads and snakes!

Teen intern Victor with the LAP LOB

An animal that is featured a lot during these presentations is one that is close to the New England psyche: the North American lobster! In Visitor Education jargon, that’s a LOB. This animal, common to many seaside restaurants, is also a common exhibit animal throughout the Aquarium and is one that visitors like to see up close. It does take a little bit of preparation to get the lobster ready to go!

Getting the container set for the lobster

Most of our live animal presentation animals are kept behind the scenes. Once the interpreters are in the area, they need to prepare the holding container that the animal will be shown in. For the lobsters, that involves cold water, ice packs and an aerator to keep oxygen amounts at peak levels! Once the container is set; it’s an elevator ride downstairs to the main stage and then show time for both the lobster and the educators!

Teen interns Destiny, Victor and Volunteer Laura get ready to present

The particular lobster the educators brought out for this presentation is a fan favorite; can you guess why?

LAP lobster for the day-cool colors!

Visitors are completely blown away by this lobster’s unique coloration! Lobsters get their shell color from their diet and their genetics; this one has particularly unique DNA that causes its shell to be two different colors split right down the middle! It’s a pretty special lobster and one that visitors can only see during a LAP.

Some young visitors get a close-up view

In addition to the lobster, the educators bring down some biofacts or tools that are used in the lobster industry.

Tools of the trade-the LAP trade!

Visitors are allowed to touch them, pick them up and take pictures with them. When was the last time you were able to touch a pair of 19 pound lobster claws?

Some BIG claws

So next time you are at the Aquarium, check out the daily schedule to see when the next LAP is happening. It may or may not be the lobster featured today, but it will be always be a neat experience to be that up close to one of our Aquarium animals!

Any questions? Meet us in the Blue Planet Action Center, we'll be happy to answer your questions about our amazing live animals!

-Jo

The Thinking Gallery: Flower Hat Jellies

Jellies are found in a number of areas around the Aquarium. You can find them on both floors of the West Wing (the same area where you can find our new Trust Family Foundation Shark and Ray Touch Tank), in a number of behind-the-scenes areas and also on the second floor in the Thinking Gallery. While the species on display are known to change, we currently have a beautiful species known as flower hat jellies (Olindias formosa).



These intricate animals are found naturally off the coast of Southern Japan, Brazil and Argentina. They are thought to be quite rare, but their conservation status is not currently known. While they don’t move around that often, they certainly can. Like all true jellies, or cnidarians, they have stinging cells called nematocysts. A flower hat jellies’ sting is painful, but is usually non-lethal to humans. You can read more about jellies on a previous post.



Flower hat jellyfishes, photo courtesy Fred Hsu via Wikimedia Commons

These jellies eat mainly small fish and crustaceans. Here at the Aquarium they are fed live zebrafish. There is no set feeding schedule, so getting to see them fed is just luck of the draw (as a hint, they are at varying times on Saturday, Tuesday and Thursday). It’s a pretty interesting feed. Check out the video below to see how it works!




See you in the galleries!

-Sam

It's a bird! It's a plane! It's a... whale?!

As you walk up the ramp from the Thinking Gallery on the second floor to the Rivers of the Americas Gallery on the third floor, you may notice a huge structure hanging above your head. It may look like a dinosaur skeleton, but it is actually the (not quite complete – more on that later) skeleton of a North Atlantic right whale. If you follow the Right Whale Research Blog you’ll already know a lot of about these incredible, but unfortunately critically endangered, animals.

A 35-foot North Atlantic right whale skeleton hangs suspended above the walkway.

The Aquarium estimates that there are only about 430 individuals of this species still around. In the past they were hunted nearly to extinction for their meat and oil. In fact, the name right whale comes from the fact that they were considered the right whale to hunt, due to their slow movements and the fact that they float after they’re killed. Fortunately, they are now protected from whaling worldwide. However, they still face a lot of danger from boat collisions and entanglement in fishing gear. Definitely check out our Right Whale Research Blog for more information on what the Aquarium is doing to protect these majestic animals.

Right whale researchers in the field.

Our particular skeleton is about 35 ft long, so it was most likely a juvenile whale. Adult Northern right whales can grow between 45 and 55 ft in total length, and weigh up to 70 tons. A fascinating feature of the skeleton is the structure of its pectoral flippers. Looking at them, you can see that whales actually have five digits, like us. I think it’s just a cool reminder that we’re more similar to other animals than we sometimes realize.

Notice the five digits of the North Atlantic right whale’s flipper.

As I mentioned earlier, this skeleton is not quite complete. One thing people don’t always realize is that whales’ ancestors lived on land. As competition intensified on land, some mammals adapted once again to the ocean to take advantage of unused food resources. Some marine mammals, like our fur seals and harbor seals, still have both front and hind legs, but whales don't. However, while whales don’t have any usable hind limbs, many do have tiny pelvic bones embedded in muscle. Bones or organs that are present but no longer seem to be of much, or any, use to an animal are known as vestigial (one of my favorite words!). An example in humans would be our wisdom teeth. With our right whale skeleton these vestigial pelvic bones are not present, but would be floating somewhere between the ribs and the tip of the tail.

In this diagram, the letter C indicates the vestigial hind limbs of a whale.

So next time you’re at the Aquarium, don’t forget to look up! There are more than just tanks to explore when you’re here.

-Sam

Walking Back Through Time: The Ancient Fishes Exhibit

Since so much of life on Earth emerged and diversified in the ocean, walking around the Aquarium can be a bit like walking back through time. This is especially true in the Ancient Fishes exhibit in the Aquarium’s Thinking Gallery.

Many of the ancestral forms of these fishes first appeared hundreds of millions of years ago. That makes these fish older than the oldest dinosaurs! At that time, much of North America was a large equatorial swamp. As the water temperatures rose, oxygen levels dropped. As a result, some of these fish developed new ways of getting essential oxygen from the air.

Let’s take a closer look at one of our ancient fishes:

(Australian lungfish photo by Tannin)


Is that a giant salamander? Actually it’s a Australian lungfish. Though this Australian lungfish has a single lung, it mostly uses its gills to breathe.

The African lungfish, however, has two lungs and can actually drown if held underwater. During the dry season, this species can burrow into mud and spend several years in a dormant state called estivation. [Note: In 2009, Aquarium trainers worked on training an African lungfish to swim through a tube to get food. Photos and video from those efforts are in this post, scroll down.]

(African lungfish photo by Jeremy Brodt)

Looking at these animals, with their air-breathing habits and paired limbs, it isn’t too hard to imagine that amphibians like this axolotl below evolved from fishes such as these.

(axolotl photo by Stan Shebs)

In fact, all vertebrates—including reptiles, birds and mammals—evolved from ancestral, air-breathing fishes.

And just to set the record straight, just because a fish species is considered "ancient" does not mean that it is primitive. So-called "ancient" fishes are themselves the result of hundreds of millions of years of evolution, and are very well-adapted to the habitats in which they live.

-Dave

What's Up, Dock?

A lot of fun outdoor programs start up at the Aquarium during the summer. One is the Dock Program, which aims to connect visitors to the ocean habitat right outside the Aquarium's doors. Boston Harbor is a beautiful and fascinating environment, with lots of animal life living just out of view. But not everyone even knows the Harbor is a harbor and not a river. So, to help our visitors get to know the harbor, we have placed a crab trap and other pieces of equipment into the harbor just off of our dock.

From left: Teen interns Alex Rojas, Kenneil Toney and Adora Thompson set up for the dock program

Throughout the week (especially on Thursdays, Fridays and Saturdays) we pull these up to see what kind of animal life we find. But we don't just look at the animals; we try to learn something about them as well. Our teen interns (and visitors who want to participate) take observations on the time of day, the weather conditions, the tidal heights and the turbidity of the water (or the water transparency) to learn more about the conditions under which our animals live. This also serves as an introduction to basic marine science.

In the photos below, you can see our teen interns setting up for the Dock Program and gathering data, and you can see a couple of the animals they found during that day's program.

Teen intern Adora Thompson takes a secchi disk measurement. By lowering the secchi disk into the water and measuring the depth at which the white part of the disk is no longer visible, you can learn some basic information about the turbidity (cloudiness) of the water. 

A female lobster and a female spider crab are caught during the day's dock program.

-Sam

Great Things Come in Small Packages (Cuttlefish Eggs)

What has 18 tentacles, 9 beaks, 72 arms and thousands of color changing cells?
It’s the cuttlefish exhibit in the New England Aquarium’s Tropical Gallery!

Dwarf Cuttlefish (Sepia bandensis)

Located on the first level of the exhibit area, the cuttlefish exhibit is currently home to nine dwarf cuttlefish (Sepia bandensis). These small, four inch relatives of squids and octopuses are cephalopods, meaning “head-foot.” And they do look like they are just that: a head and a bunch of feet! Most noticeable on the front of their bodies are their two feeding tentacles and eight arms that they use these to snare prey, like shrimp and small fish. Once the food is caught, the cuttlefish breaks up the food with their hard beak and it’s snack time!

How many cuttlefish can you find?

Resembling small flying saucers, cuttlefish use a flexible fin and jet propulsion to move both vertically and horizontally in the water! They also have the most amazing ability to change their appearance with thousands of color-changing cells all over their skin. It’s thought that cuttlefish use their color changing abilities to aid in communication, mating and to mesmerize prey. Check out the video below … if you look closely, you will be able to see the cuttlefish change the color pattern of its skin!

And while this entry was being written, the cuttlefish went and did something that makes the exhibit even more amazing-they laid eggs! Each of the small, ink colored eggs contains a growing cuttlefish that will hatch in approximately 25-30 days. If you visit soon, you may still see the eggs. However, our aquarists will remove the eggs soon in hopes of hatching, and then raising, some new cuttlefish for the exhibit. Here's a good image that shows what to look for in the exhibit.

Cuttlefish Eggs (Steinhart Aquarium)

So come visit these tentacled, color-changing flying saucers. They might be small, but great things do come in small packages.

-Jo

Rays of the Touch Tank: Leopard Whiptail Stingray

One of our most beautiful animals in The Trust Family Foundation Shark Ray Touch Tank is also one of our most elusive. The leopard whiptail ray (Himantura undulata) has an intricate skin pattern that certainly does call to mind its namesake, the leopard.

Photo credit: Marcel Burkhard via Wikimedia Commons

Leopard whiptail stingrays can grow to about 1.4 m wide. As with other whiptail rays, their tail is very long compared to their body and the animal's total length can be upwards of 4 m. These rays are found naturally in the Indo-Pacific region from the Bay of Bengal to Northern Australia.

 

Photo copyright: Andy Murch via Elasmodivers.com

These rays have a varied diet, but are thought to eat mainly mollusks and crustaceans. Like other rays they use their strong jaw to crush the shells of these animals to get to the soft animal inside.

Photo credit: Sam Cheng

When you visit the tank it may be hard to see this animal right away. However, if you're patient and look towards the back of the tank, you may be lucky enough to "spot" this gorgeous animal. I don't know of anyone getting to touch this shy animal yet, but you never know. If you do get super lucky and have the opportunity to interact with this animal, be sure to come back here and comment about your experience! Just be prepared for jealous comments from educators!

-Sam

Just the biofacts: What is sandtiger shark skin made of?

When you visit The Trust Family Foundation Shark and Ray Touch Tank, you probably will have only a few seconds to touch a shark before it swims past you. But find one of our educators in the exhibit, and you could have a chance to spend a lot more time with some shark skin.

 A sandtiger shark in the Giant Ocean Tank

One of the biofacts that educators bring into the touch tank exhibit is a piece of sand tiger shark skin (shown at left). When you get up close to the skin, you can see that it has tiny scales called dermal denticles (“tiny skin teeth”). Dermal denticles point tailward, so when you feel shark skin from head to tail, it feels smooth, but from tail to head, it feels coarse like sandpaper. The denticles are also strong, giving the shark a flexible, armor-like skin. This helps reduce drag and allows the shark to move more quickly through the water.



If you take a closer look at the skin, you may find something else amazing. Look for small holes or pores—those are the Ampullae of Lorenzini. Located around the snout and under the mouth of a shark, these special organs can sense the electrical fields in the water, giving sharks their “sixth sense”! They help the shark find food and may assist in locating birthing grounds.

An up close look at the sandtiger shark skin showing the Ampullae of Lorenzini

Sand tiger sharks are listed as Vulnerable to Extinction due to capture for sport and by commercial fisheries. Many types of sharks have been hunted for their skin, which some cultures use as sandpaper or to make purses, wallets and shoes. They are also caught as bycatch in nets of other fisheries.

We can reduce the number of sharks caught by not purchasing shark-related items and by choosing seafood that’s caught in a sustainable way, reducing shark bycatch. Visitors can check our website for additional information on sustainable seafood choices.

-Jo

[Learn more about sandtiger sharks in these posts from the Aquarium's divers blog: Why do sharks have so many teeth? How do sharks get a medical exam? and Does Myrtle the green sea turtle ever try to steal the sharks' food?]