5/15/09

#44: Many People Ask - Why do sharks have so many teeth?

As one of our sand tiger sharks swim by you often hear visitors gasp and say “Look at all those teeth!!!”

But why do sharks have so many teeth?
Sharks and rays are elasmobranches, or cartilaginous fishes. This means unlike us or any of the other fish that live in the Giant Ocean Tank, their skeleton is made out of cartilage not bone. Therefore shark's teeth are not anchored in bone but instead loosely embedded in their gums above their jaws. Not being anchored in bone means a shark's tooth can fall out very easily. When a tooth falls out it is replaced with another tooth from a row of teeth behind it, in a conveyor belt fashion. Depending on the species 3-15 rows of teeth can be visible! One shark can produce thousands teeth in its lifetime!

Our sharks in the GOT are no exception; they often loose their teeth, and we will find them around the tank. Here are a few pictures of some of our trophy teeth.

Even though it may look quite scary it is important that the sharks have so many rows of teeth, if they lost most of their teeth they wouldn't be able to feed which is very problematic since they don't make dentures for sharks.

- Andrea

Labels: Andrea, Many People Ask, Nurse Shark, sand tiger shark, sharks

4/13/09

#39: Many People Ask - What's in a Name?

Our visitors often ask if we name our animals. The answer is yes and no. With over 600 individual animals in the Giant Ocean Tank, it would be impossible to name them all, but we do name our sharks, rays, and sea turtles. Here are the names of some of our more prominent animals in the GOT.

This is Carolina, one of our loggerhead sea turtles. She was named for the many loggerhead nesting beaches in the Carolinas.

This is Retread, another loggerhead sea turtle. Retread came to us through our rescue and rehab department. When found, she was so lethargic due to a condition known as cold stunned, that she was thought to be dead. Luckily one of the biologists noticed a faint flipper movement and she was saved. According to Mirriam-Webster, the word "retread" means to press back into service or to make over as if new.

This is Scute, our Kemp's ridley sea turtle. She was named for the individual plates on a sea turtle's shell, which are called scutes.

The video below shows our three sand tiger sharks, Judith, Markham and Galilee. Judith (Point Judith) and Galilee are named after harbor communities in Rhode Island where sand tiger sharks can be found. Markham is named after the Markham 75FSW, a sunken ship that is part of North Carolina's artificial reef program. Sand tiger sharks are commonly seen in the area. The first shark in the frame is Judith, then Markham and finally Galilee.

The next video shows our Southern stingrays, Daisy and Ripley. Daisy got her name from the scientific word for southern stingray, Dasyatis americana. Ripley was named after the institution she came from; Ripley's Aquarium of the Smokies. The first ray is Daisy, the second is Ripley.

And last but certainly not least, Myrtle will always be Myrtle.

-Sherrie

Labels: GiantOceanTank, Kemp's ridley, loggerhead, Many People Ask, names, sand tiger shark, sea turtle, southern sting ray, video

3/23/09

#37: Many People Ask - Do fish go to the doctor?

There's no questioning that the Giant Ocean Tank (GOT) is home to a lot of animals. Ever wonder what happens when one of them gets sick or injured? Is that why we have a nurse shark?

Enter the New England Aquarium's Animal Health Department (AHD) - also known as the 'Wet Vets'.

Yes, the Aquarium has an entire department dedicated to the health and well-being of all the creatures that call the New England Aquarium home. Comprised of veterinarians, medical technicians, interns, and volunteers, the AHD staff attend to any medical issue that crops up - from a tiny fish with a gas problem, to a 240 lb. shark with spine issues. The department is supported by a state-of-the-art medical facility that allows the vets to perform everything from radiographs (x-rays) to complex surgeries.

Here's a few pictures of the AHD facility:

AHD staff are always rolling up their sleeves (quite literally) and getting right into the thick of things - even to the point of making house calls into the GOT.

Every week, members of the veterinary staff meet with senior GOT staff in what's called 'rounds' to discuss and address any health issues regarding the inhabitants of the GOT.

Sometimes, as a result of rounds, we decide to do an animal extraction so the vets can get a closer look. This was recently the case with one of our green moray eels.

In the above video, Sherrie and I tease the eel out of its coral home and into a specially made eel catch bag.

Once out the tank the eel is carefully anesthetized (a great idea for both the eel's AND the humans' sake!) so the vets can obtain radiographs, blood samples and scan her insides with ultrasound.

Here's the ultrasound video:

Of course our wet vets wouldn't live up to their name without sometimes gearing up and going in. Here you can see Keiko, a Veterinary Fellow, and Deana, the AHD Lab Manager, getting a closer look at Retread's eyes to see if she should be pulled for a more detailed examination. Retread, one of our two loggerhead turtles, is a rescued turtle that had sustained damage to her eyesight when she was cold stunned and stranded off Cape Cod years ago.

It was determined that further examination wasn't necessary, so she could be left where she was. However the vets wanted a routine blood draw from her loggerhead friend, Carolina, so up she came - all 160 lbs. of her.

When restraining a large, powerful, and uncooperative turtle, some creative thought needs to be called for. Carolina is secured in a custom made sling and then suspended from a hoist. This prevents her powerful flippers from getting a purchase on anything.

Then there's our littlest turtle, Scute, a Kemp's ridley. She puts up no fuss at all as veterinarian Charlie conducts an untrasound examination.

As you can see, there's a small army of Aquarium medical staff digilently working toward maintaining the health of the Aquarium's aquatic residents, and they even make house calls.

So no, a sick fish definitely does not visit our nurse shark. That would be like Little Red Riding Hood visiting the wolf dressed up as Grandmother...

Happy diving.

- John

Labels: Animal Health Department, GiantOceanTank, green moray eel, John Hanzl, Kemp's ridley, loggerhead, Many People Ask, veterinarian

1/15/09

#28: Many People Ask - Annual Census

How many fish are in the Giant Ocean Tank? How many sharks? Sea turtles? Stingrays? How many different species are in there? Visitors are always curious to know what they are looking at in the exhibit...

In order to find out, we spend the entire month of December counting each and every fish in the tank. Each staff diver picks a species to concentrate on during a particular dive and tallies their numbers. We keep an on-going record up on the dive office door:

We perform the annual census for different reasons. It allows us to accurately answer our visitor's questions. It's also an important part of record keeping and allows us to monitor, and manage, our collection. Because we have data going back four decades, we can track the longevity of particular species. It is also a requirement for AZA institutions like the New England Aquarium.

Some counts are easy, like the three sand tiger sharks. This is our largest female:

Here's a video of all three (You'll see the smallest one has a superficial mark on its tail):

Two loggerhead sea turtles:

We have two southern stingrays:

And a movie of them too:

One nurse shark:

We use underwater slates to write down note:

We use different techniques for different fish. The angelfish love to eat lettuce so it makes them easier to count:

It takes several divers to get an estimate for some of the schooling fish, like these smallmouth grunts:

We have two cownose rays (one thinks its feeding time):

Some of our fishes include four sargassum triggerfish:

Two scrawled cowfish:

Four balloonfish:

We have three green morays, one spotted moray, and one goldentail moray:

In all, we counted 620 individual fish and 129 different species.

Of course, there's only one Myrtle:

- Sarah

Labels: 2008 Census, angelfish, balloonfish, Census, cowfish, GiantOceanTank, goldentail eel, grunt, Many People Ask, moray, Sarah, southern sting ray, triggerfish, video

12/6/08

#22: Many People Ask - Does anyone or anything ever fall into the GOT?

Visitors often ask if anyone or anything ever falls into the GOT. Well, I'm happy to report that a person has never fallen in. However, over the years, many interesting "things" have fallen in. Some of the more common items are pencils, pacifiers, keys, money, earrings, mittens, hats, paper, water bottles, and lots and lots of sunglasses.

More often then not, visitors do not want their soggy items back, so the divers are never at a loss for a pair of sunglasses.

Before the sunglasses are retired to the "sunglass drawer," the divers like to have a little fun with them.

Not sure Myrtle agrees that this is so much fun!

I think the most unusual thing I have ever found in the GOT was a Guns and Roses CD; the most expensive was a cell phone.

So the next time you visit the Aquarium enjoy the top of the GOT, but be sure to hold onto your stuff!

- Sherrie

Labels: Giant Ocean Tank, GiantOceanTank, Many People Ask, myrtle, Sherrie

11/25/08

#20: Many People Ask - What do the fish eat?

"What do the sharks eat?" and "What do the sea turtles eat?" and "What do the fish eat?"

People often wonder how and what we feed our animals. We feed four times a day: twice in the morning (10:00am and 11:15am) and twice in the afternoon (2:30pm and 3:30pm). You can plan your visit to watch us dive in the tank using the daily schedule.

Shark Food
Here's our typical shark diet, which is supplemented with vitamins daily:

The sharks are the first ones to be fed in the morning and the last ones to eat at night. This helps us ensure that they won't "snack" on anything overnight. They get large fish and squid which is offered on a long stick to keep our hands away from those sharp teeth!

Myrtle Food

This is what Myrtle eats:

A lot of people ask about Myrtle's food too. She is a green sea turtle so she would normally eat a large quantity of sea grasses (she'd also get an occasional crab or fish while foraging). We give her a wide variety of greens, some protein (shrimp, clam, squid, or small fish), and nutrient-packed turtle gel (the green square in the upper right corner of the photo). She also eats broccoli, cabbage, romaine lettuce, green pepper, zucchini, and Brussels sprouts (her favorite). She also gets daily vitamins.

Other Sea Turtles Eat ...

The other sea turtles (Kemp's ridley and loggerheads) eat a mix of protein based on what they eat in the wild. They get a variety of capelin, squid, herring, smelt, shrimp, clam, and silversides. They also get vitamins and are fed using a stick so we don't get accidentally bitten (they have really strong jaws).

Fish Food
Here is what we feed some of the fishes:

We have many omnivores that like to chomp on peas and corn (the bottle pictured on the right). Little fish that tend to hide get fed krill (the bottle pictured on the left). We also bring heads of romaine lettuce in the tank and are instantly mobbed by angelfishes and blue tangs. They love eating greens. We also give them little bunches of mint and parsley which has good nutritional value.

Our Food Fridge

Here's a picture of inside the fridge after morning food prep:

The tupperware on the top shelf is filled with fish for surface feeding (porcupinefish, barracuda, needlefish, and cobia). Two of the yellow buckets on the bottom are filled with a variety of fish for the tarpon and permits. The other yellow bucket is filled with de-tailed shrimp (so we don't stab our hands--those tails are really sharp!) The stingrays love the shrimp feeding at 2:30pm. We encourage the rays to feed against the windows so people can get a great view of them eating.

- Sarah

Labels: cownose ray, feeding, fish, GiantOceanTank, Many People Ask, myrtle, sand tiger shark, Sarah

About

The Giant Ocean Tank (GOT) is the New England Aquarium's signature exhibit. The tank is home to more than 630 individual animals representing more than 130 species. Several times a day it is also home to Aquarium divers who feed the animals, help provide medical treatment and clean the exhibit. This blog is written by those divers to give you the inside story on the GOT.