Discover The Largest Snapping Turtle Ever Recorded

Written by Hannah Ward
Updated: June 12, 2023
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Snapping turtles are one of the oldest types of turtle around, having been around for approximately 200 million years – even during the time of the dinosaurs! The species also have a lifespan of more than 100 years.  These fascinating reptiles spend most of their time in freshwater ponds, streams, and rivers and can grow to almost 3 feet long while reaching weights of well over 150 pounds.

But just how big can snapping turtles get?  We’ll discover the largest snapping turtle ever recorded and see how they compare against other turtles!

Snapping Turtle in the zoo

Snapping Turtle

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©Willy Logan / Creative Commons

The Background on Snapping Turtles

Snapping turtles are large freshwater turtles that are unable to withdraw their head and legs fully into their shells, and so have extremely powerful jaws that they use to defend themselves with by snapping, hence their name.  However, despite their somewhat fearsome name, they’re not particularly dangerous to humans and prefer to retreat unless they feel threatened.

These fascinating turtles are excellent swimmers and are found mainly in freshwater locations across North America.  However, there is another smaller population – the Bellinger River snapping turtle – which is endemic to the Bellinger River in Australia.

There are two main types of snapping turtle – the common snapping turtle, and the alligator snapping turtle which is the larger of the two.  Common snapping turtles average 8 to 14 inches long and usually weigh between 10 and 35 pounds, while alligator snapping turtles are usually between 13 and 32 inches long and weigh anything from 19 to 176 pounds.

Common snapping turtles are best known for their extremely mobile head and neck which is often described as being snake-like, hence their scientific name – Chelydra serpentina – after their serpent-like characteristics.  As their name suggests, alligator snapping turtles got their name because they have a similar appearance to an alligator, with the ridges on their shells being described as being similar to the ridges on an alligator.

Possibly one of the most fascinating things about common snapping turtles is that during harsh winters they don’t breathe for six months while the water is covered by ice.  Instead of breathing the traditional way, they breathe using something called extra-pulmonary respiration.  This is where they receive oxygen by pushing their heads out of the mud so that gas exchange can take place through the membranes of their mouth and throat.   Although they don’t hibernate in the traditional sense, snapping turtles exist in a “sleepy state” during this period.  During this time they use very little energy and shut down all parts of their body that aren’t needed.

Snapping Turtle on grass

Snapping Turtle

©Moondigger / Creative Commons

The Largest Snapping Turtle Ever Recorded

The largest snapping turtle ever officially recorded was a 16 year old alligator snapping turtle that weighed in at a massive 249 pounds.  This massive turtle was weighed at Shedd Aquarium in Chicago in 1999 prior to being sent to the Tennessee Aquarium on breeding loan. It is no longer in Tennessee, however; it’s current snapping turtle weighs only 165 pounds.

However, there are reports of an even bigger alligator snapping turtle found in Kansas in 1937.  Although it was never officially recorded, its weight was rumored to be a whopping 403 pounds!

Where is the Shedd Aquarium on a Map?

Chicago is, of course, a major metropolitan area in Illinois on the west bank of Lake Michigan. The Shedd Aquarium is in the heart of the city on the Lake Michigan shoreline, right next to the world-famous Field Museum of Natural History, one of the largest such museums anywhere and known for its many research initiatives. The Shedd Aquarium is a state-of-the-art indoor aquarium showcasing a variety of habitats and providing amazing views of Lake Michigan.

Snapping Turtle on grass

The largest snapping turtle official recorded weighed 249 pounds

©Gary M. Stolz / Public Domain

How do Snapping Turtles Compare with other Turtles?

Compared to other freshwater turtles, the average length of snapping turtles is only slightly smaller than the largest, the Yangtze giant softshell turtle which can grow to length of around 39 inches.  However, at around 220 pounds they do weigh more than the average alligator snapping turtle.

Despite being an impressive size for a freshwater turtle, snapping turtles are still much smaller than sea turtles, with leatherback turtles averaging 1,500 pounds and the largest sea turtle ever recorded weighing a massive 2,019 pounds!

Snapping turtles have long tails

©Mjbaker / Creative Commons

Were Ancient Snapping Turtles Even Bigger?

Although not a lot is known about extinct species of snapping turtles, it is quite easy to assume that they were much bigger than the snapping turtles that are around today.  The largest extinct turtle is the Archelon which was a sea turtle that reached an impressive length of 12 feet and lived between 66 and 83 million years ago.

However, the second largest was the Stupendemys which was a large freshwater turtle that reached 11 feet long and lived in what is now South America between 5 and 10 million years ago.  It is believed that, like the alligator snapping turtle, Stupendemys ate a mixture of plants and animals and lived at the bottom of freshwater rivers and lakes.

How Snapping Turtles Reproduce

Generally, only nesting females ever venture onto land, with the males preferring to stay in the safety of the water throughout the whole of their lives.  The females usually leave the water under the cover of darkness to find a sandy spot to make their nest.  Once they’ve found a suitable spot, they dig a hole around 6 inches deep and lay between 25 and 80 eggs and then fill the hole back in and return to the water.  Female snapping turtles don’t look back once they’ve laid their eggs and don’t nurse or raise their young.

The length of time that the eggs take to hatch is temperature-dependent and can take between 9 and 18 weeks.  The sex of the hatchlings is also determined by the temperature of the nest – with a cooler nest producing males, and a warmer nest producing females.  When they are born the hatchlings are only around 1 inch long and will usually immediately head for the water.  However, in the most northern locations, common snapping turtle hatchlings might remain in the nest over winter if it has become covered by ice, although this poses a great risk to them due to both the cold and predators.

Predator or Prey: Are Snapping Turtles Under Threat?

All snapping turtles are omnivores and eat a mixture of plants, insects, frogs, and fish, although the larger alligator snapping turtles also eat birds, small mammals, and reptiles – such as snakes and the smaller common snapping turtles.

Alligator snapping turtles have a particularly unique method of catching their prey – they sit on the bottom of the stream or pond with their mouth wide open.  Amazingly, their tongue looks like a worm which they use to attract fish which literally swim straight into their mouths.

Due to their size, snapping turtles don’t have many predators, although coyotes, black bears, and alligators can sometimes kill adults.  Instead, their greatest threat comes from birds, foxes, mink, and raccoons who will all take their eggs and the hatchlings.  American bullfrogs, herons, large fish, and snakes are also a risk to hatchlings once they’ve left the nest.  Although snapping turtles don’t have many predators, alligator snapping turtles are still classed as vulnerable on the IUCN red list.  However,  luckily the common snapping turtle is officially considered least concern.

Snapping Turtle with mouth open

Despite their fierce appearance, alligator snapping turtles are officially vulnerable

©LA Dawson, CC BY-SA 2.5, via Wikimedia Commons – License

The Bellinger River Snapping Turtle – Almost Became Extinct in Months

As already mentioned, the Bellinger River snapping turtle is a species that is endemic to the Bellinger River in Australia.  However, they are lucky to be alive today as a virus almost wiped them out in a matter of months.

In 2015 an unknown virus that caused blindness and organ failure wiped out around 90% of the entire population in a matter of months.  The entire population would have died had it not been for rescuers saving the last few healthy turtles and beginning a captive breeding programme.  Juveniles have since been released back into the river where they are carefully monitored for any signs of disease.  The current population is now around 200 although they are still classified as critically endangered.  However, these determined turtles are still hanging on despite the odds having been stacked against them.

The photo featured at the top of this post is © Gary M. Stolz / Public Domain

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About the Author

Hannah is a writer at A-Z animals where her primary focus is on reptiles, marine life, mammals, and geography. Hannah has been writing and researching animals for four years alongside running her family farm. A resident of the UK, Hannah loves riding horses and creating short stories.

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