WEBVTT - Can a Turtle Outgrow Its Shell?

0:00:01.840 --> 0:00:07.480
<v Speaker 1>Welcome to Brainstuff, a production of iHeartRadio, Hey brain Stuff

0:00:07.520 --> 0:00:13.160
<v Speaker 1>Lauren vogelbamb Here. Turtle is the common American English word

0:00:13.280 --> 0:00:16.600
<v Speaker 1>for the three hundred and fifty sum species of reptiles

0:00:16.760 --> 0:00:21.480
<v Speaker 1>known for their characteristic shells. Sometimes you might see, especially

0:00:21.480 --> 0:00:26.680
<v Speaker 1>in British English, distinctions between land based tortoises, freshwater terrapins,

0:00:26.720 --> 0:00:30.880
<v Speaker 1>and marine turtles. But today I'm talking about the whole

0:00:30.920 --> 0:00:35.440
<v Speaker 1>mess of them using the word turtle. Okay, okay. They

0:00:35.560 --> 0:00:39.760
<v Speaker 1>live in oceans, lakes, streams, forests, and deserts all over

0:00:39.800 --> 0:00:42.920
<v Speaker 1>the world except Antarctica. They might be in a yard

0:00:43.000 --> 0:00:48.360
<v Speaker 1>or pond near you, and those shells are amazing adaptations.

0:00:48.960 --> 0:00:51.560
<v Speaker 1>The shape of a turtle shell depends on the species

0:00:51.600 --> 0:00:55.280
<v Speaker 1>and the turtle's habitat. Most land dwelling turtles have a high,

0:00:55.280 --> 0:00:58.680
<v Speaker 1>domed shell, which helps protect them from the jaws of predators,

0:00:59.080 --> 0:01:02.320
<v Speaker 1>while most aquatic turtles have a more streamlined, flattened shell

0:01:02.560 --> 0:01:06.880
<v Speaker 1>that lets them glide through the water. Turtle's shells are

0:01:06.920 --> 0:01:09.880
<v Speaker 1>made up of two parts, the carapas, which is the

0:01:10.000 --> 0:01:13.400
<v Speaker 1>upper half on the turtle's back, and the plastrin, which

0:01:13.440 --> 0:01:17.759
<v Speaker 1>is the lower half under the turtle's belly. Structures called bridges,

0:01:17.800 --> 0:01:21.080
<v Speaker 1>fasten the two together. The turtle sides. They're generally bony,

0:01:21.120 --> 0:01:24.800
<v Speaker 1>but in soft shell turtles they're flexible. For the many

0:01:24.800 --> 0:01:28.000
<v Speaker 1>species of turtles able to retract into their shells, a

0:01:28.200 --> 0:01:31.400
<v Speaker 1>hinge joins the two halves together That allows the carapas

0:01:31.400 --> 0:01:34.720
<v Speaker 1>and plastron to close tightly when the turtle draws itself in.

0:01:36.959 --> 0:01:40.600
<v Speaker 1>Both the carapus and plastron are made of bone, including

0:01:40.640 --> 0:01:43.240
<v Speaker 1>about fifty to sixty rib and backbones in the upper

0:01:43.240 --> 0:01:46.319
<v Speaker 1>shell and a fusion of clavical and rib bones in

0:01:46.360 --> 0:01:51.640
<v Speaker 1>the lower shell. On the outside of the bone, each

0:01:51.680 --> 0:01:55.800
<v Speaker 1>shell half is covered in scoots, sometimes called shields, which

0:01:55.840 --> 0:01:59.960
<v Speaker 1>are overlapping pieces of keratin the same substance as human fingernail.

0:02:00.840 --> 0:02:05.000
<v Speaker 1>The scoots provide a protective coating. Most soft shelled species

0:02:05.040 --> 0:02:08.000
<v Speaker 1>don't have scoots, but they do have a layer of tough,

0:02:08.120 --> 0:02:14.680
<v Speaker 1>leathery skin. So a turtle's shell offers intricate skeletal protection.

0:02:15.360 --> 0:02:21.160
<v Speaker 1>But can a turtle outgrow its shell? Unlike a hermit crab,

0:02:21.320 --> 0:02:23.800
<v Speaker 1>a turtle isn't able to trade in one shell for

0:02:23.840 --> 0:02:28.000
<v Speaker 1>another if it's damaged or just doesn't fit anymore. Hermit

0:02:28.040 --> 0:02:30.520
<v Speaker 1>crabs will trade shells because they don't grow their own.

0:02:30.960 --> 0:02:34.200
<v Speaker 1>They find their shells in their environments. But a turtle's

0:02:34.200 --> 0:02:36.920
<v Speaker 1>shell never falls off and is never too large or

0:02:36.960 --> 0:02:41.040
<v Speaker 1>too small because it grows with the turtle. It's made

0:02:41.040 --> 0:02:43.640
<v Speaker 1>from the turtle's rib cage and spine, and it's attached

0:02:43.680 --> 0:02:46.639
<v Speaker 1>to the internal bones with the turtle's body. Just as

0:02:46.680 --> 0:02:49.240
<v Speaker 1>your vertebrae grow with you, are the same as true

0:02:49.280 --> 0:02:54.440
<v Speaker 1>for a turtle's shell. For most species, as the turtle

0:02:54.480 --> 0:02:57.760
<v Speaker 1>and its shell grow, the scoots on the shell shed

0:02:57.919 --> 0:03:01.160
<v Speaker 1>or peel away to make room for new, larger scoots.

0:03:01.720 --> 0:03:05.120
<v Speaker 1>The shedding is a natural process that takes place over time,

0:03:05.360 --> 0:03:08.880
<v Speaker 1>and individual scoots are cast off during daily activities like

0:03:08.960 --> 0:03:14.040
<v Speaker 1>swimming and basking in the sun. Because turtles are cold

0:03:14.080 --> 0:03:17.680
<v Speaker 1>blooded reptiles, they rely on external ways of heating and

0:03:17.720 --> 0:03:21.600
<v Speaker 1>cooling themselves. While basking is one way that turtles raise

0:03:21.639 --> 0:03:24.840
<v Speaker 1>their body temperature, it also helps them shed scoots by

0:03:24.960 --> 0:03:29.200
<v Speaker 1>drying them up, leaving them ready to fall off. Some turtles,

0:03:29.400 --> 0:03:31.960
<v Speaker 1>like the South American river turtle, lend each other a

0:03:32.040 --> 0:03:35.160
<v Speaker 1>hand in the shedding process. Well, they lend each other

0:03:35.280 --> 0:03:38.240
<v Speaker 1>a jaw by pulling loose scoots and algae off each

0:03:38.280 --> 0:03:42.400
<v Speaker 1>other's shells. This is done gently, though, since both pain

0:03:42.520 --> 0:03:47.280
<v Speaker 1>and pressure can be felt through the shell. When old

0:03:47.280 --> 0:03:51.360
<v Speaker 1>scoots aren't suitably shed, turtle shells can develop infection and disease.

0:03:52.280 --> 0:03:56.080
<v Speaker 1>In rare instances, scoots are shed too frequently, leaving the

0:03:56.080 --> 0:04:00.160
<v Speaker 1>bones of the shell unprotected and soft. Overabundant scoots, shedding

0:04:00.240 --> 0:04:05.480
<v Speaker 1>has been linked to larger problems like renal failure. Shell

0:04:05.560 --> 0:04:09.000
<v Speaker 1>health is also dependent on bone health. A metabolic bone

0:04:09.000 --> 0:04:12.760
<v Speaker 1>disease caused by inadequate calcium intake of poor exposure to sunlight,

0:04:13.000 --> 0:04:16.080
<v Speaker 1>as well as diseases of the liver, kidneys, and thyroid

0:04:16.320 --> 0:04:20.719
<v Speaker 1>can all result in soft or misshapen shell bones. Ulcers,

0:04:20.839 --> 0:04:23.599
<v Speaker 1>also known as shell rot, can cause permanent shell and

0:04:23.640 --> 0:04:30.120
<v Speaker 1>scute deformities. Shell disease doesn't occur as frequently as injury,

0:04:30.279 --> 0:04:34.360
<v Speaker 1>though fractured shells are common and happen when turtles are

0:04:34.440 --> 0:04:39.080
<v Speaker 1>hit by cars or attacked by other wildlife. Some veterinarians

0:04:39.120 --> 0:04:42.479
<v Speaker 1>are able to repair broken shells with bonding materials, but

0:04:42.760 --> 0:04:45.760
<v Speaker 1>one of the fantastic things about a turtle's shell is that,

0:04:45.839 --> 0:04:49.480
<v Speaker 1>since it's made of living materials, it can slowly repair

0:04:49.520 --> 0:04:57.599
<v Speaker 1>itself and regrow Today's episode is based on the article

0:04:57.760 --> 0:05:00.000
<v Speaker 1>can a Turtle Outgrow its Shell? On How Stuff Works?

0:05:00.600 --> 0:05:04.240
<v Speaker 1>Written by Maria Tremarchy. Brain Stuff is production of iHeartRadio

0:05:04.320 --> 0:05:06.840
<v Speaker 1>in partnership with HowStuffWorks dot Com and is produced by

0:05:06.839 --> 0:05:10.360
<v Speaker 1>Tyler Klang. Four more podcasts my heart Radio, visit the

0:05:10.400 --> 0:05:13.600
<v Speaker 1>iHeartRadio app, Apple Podcasts, or wherever you listen to your

0:05:13.600 --> 0:05:14.400
<v Speaker 1>favorite shows.