Written by Emily Fowler, Sea Trust Intern.
When we think of turtles, images of slow-moving creatures basking in the sun or gliding gracefully through water might come to mind. But among the wide family of turtles, terrapins hold a unique place. These semi-aquatic reptiles living in a world between land and water, thriving in brackish coastal environments, freshwater rivers, and marshy wetlands. With their beautifully patterned shells and surprisingly complex behaviours, terrapins are much more than just pond dwellers.
In this blog, we will dive into the world of terrapins: exploring their habitats, diets, behaviours, and the conservation challenges they face, as well as diving into the terrapins that Ocean Lab look after.
What are Terrapins?
The name terrapin is derived from the Indian Algonquian word ‘torope’ which means “little turtle”. They are part of the Testudines order, meaning that they share the same characteristics as other animals in this order such as turtles and tortoises. There are over 350 species of turtle throughout the world, but there is no specific number of terrapin species. Terrapins possess webbed feet with claws, which help them with both swimming and walking on land, making them in some ways, a combination of a turtle’s ability to swim, and a tortoise’s ability to walk on land. They are almost totally aquatic but need dry land to bask. They are omnivores, typically eating insects, small fish and crustaceans, but also with an appetite for leafy greens and aquatic plants.
Species Spotlight
At Ocean Lab, we are very lucky to have two gorgeous terrapins Michelle and Rachel. Their story is very different to the other marine wildlife we look after in our catch and release aquarium. Our terrapins were rehomed from a local school where their names once were Michealangelo and Rafeal, inspired by the Teenage Mutant Ninja Turtles. They were originally thought to be males, but we have since changed their names to match their femininity. They were both born in 2009, making them around 16 years old, however they are not the same species.
Habitat and behaviour:
Terrapins are believed to originate from the US, specifically surrounding the Gulf of Mexico. They prefer freshwater environments and can be found in estuaries, wetlands, marshes, mangrove swamps, lagoons and river mouths, where freshwater and saltwater mingle. This is typically where they would make their homes. As they are cold-blooded animals, they favour warmer climates where they can bask in the sun and tend to go into hibernation during the winter. They are much more active during warm weather, but also the warmth is essential for their breeding habits.
Adult female terrapins lay eggs annually between April and July. Although its normally once a year, sometimes she can lay two at times, however they don’t hatch sit on their eggs as one might think. Terrapins will cover their eggs with sand to keep them warm. They usually take 60 days to hatch, however, the eggs need to be incubated at temperatures of around 25 degrees. They start as small as a 50p coin and weigh between 6 to 10g but they grow to be much bigger.
As for their behaviour, Terrapins have a multitude of behaviours which include basking, digging for nesting or foraging, often exhibiting social interactions too. They usually remain close to a water source so that they can quickly into the water if they become stressed or scared, luckily, they are excellent swimmers. If they are frequently seen swimming, it may indicate that they are searching for a nesting site or attempting an escape. However, they do rely on feeling secure, meaning they often live in a secretive and covered environment in attempt to feel safe and comfortable.
Michelle (Mississippi Map Terrapin):
Michelle is a Mississippi Map Terrapin, originating from North America. The name Mississippi gives a small hint as to what area, however her species gets their name from the Mississippi River rather than the state, as that is often where they can be seen. The ‘map’ part of their name comes from the lines and marking on her shell that look like the contour lines on an elevation map.
They can live to be around 30+ years of age, growing up to 10 inches long. They prefer to be in the water when they feel safe, which is lucky, as they can hold their breath for 40 minutes. Michelle’s diet consists of insects, molluscs, crustaceans and vegetations; she is a sucker for a tomato too.
During a Mississippi Map Terrapin’s breeding season, the males try to impress the females by vibrating his claws on the women’s face which is known as “chin tickling”.
IUCN RED LIST STATUS: LEAST CONCERN
Rachel (Yellow Bellied Slider Terrapin):
Rachel is our other terrapin, and in some ways the bossier one. She is part of the Yellow-Bellied Slider Terrapin species, originating in the Southeast of America, in places such as Florida and Virginia. Similarly to Michelle, she too has very distinct markings that match her species name; yellow belly (bottom shell) with dark spots that get darker over age and yellow stripes on their skin. Sometimes though, they can have a yellow “S”, or a question-mark shaped marking on their face or belly, however Rachel doesn’t.
Rachel’s species can live up to 40+ years in captivity and also spends most her time in the water just like Michelle. They are most active during the day, but you can definitely catch Rachel basking under her heat lamp. A Yellow-Bellied Slider Terrapin’s diet consists of worms, fish, insects and vegetation.
IUCN RED LIST STATUS: LEAST CONCERN
Due to terrapins non-nativeness to the UK, they are considered Aliens. Terrapins are an invasive species to the UK, meaning they cannot be released into the wild. As a result, Michelle and Rachel will remain in our care together.
Terrapins as pets:
The question some of you may be asking is if terrapins are not native to the UK, how was a school originally able to home two of them? Well, terrapins were native to the UK, up until 8,000 years ago, when temperatures and climate change caused the environment to be too harsh for their survival. Then why do we still have them now 8,000 years on? In the 1990s, there was a “Teenage Mutant Ninja Turtle” craze in which the idea of owning a pet turtle was deemed pretty cool. Hundreds of thousands were imported into the Uk from the US to meet this demand, including our terrapins, Michelle and Rachel. The most common terrapin was the red-eared terrapin, which have a distinct red stripe behind each eye where you’d imagine the ears would be. If you come across a similar coloured terrapin with yellow features but no red stripe; it will most likely be the yellow-bellied slider, just like our Michelle.
Unfortunately, terrapins lost their pet appeal once owners discovered that they could grow into the size of dinner plates and develop substantial strength. This unfortunately mean that many got released into the wild. Although the importation of red-eared terrapins into the EU was banned in 1997, at the moment there are around 4,000 wild terrapins in the UK, with the largest population found in open waters and slow-flowing rivers in the midlands and southern England. As mentioned before, terrapins need especially warm conditions to breed in, making it unlikely that these terrapins will bread in the UK. As we all know the British summer weather is not particularly known for being consistently warm.
The government has implemented strict regulations in the UK, because they are considered an invasive non-native alien species, meaning they don’t naturally inhabit the Uk, but also bring with them problems for the UK coasts. Terrapins can carry salmonella, which poses a health risk to humans, they can deplete native vegetation, causing eutrophication (a process where water bodies become enriches with nutrients), as well as harming native animal populations. They spread diseases to other animals, including native species, as well as competing with native wildlife for food. All these problems can lead to severe consequences to the UK coasts.
In 2016, it became illegal to buy or sell a terrapin, however, it is now also illegal to release terrapins into the wild. Previous released pet terrapins have established wild populations in ponds and canals. Even with some being released, there is still an estimated 600,000 that are pets. If you do see any in the wild, The Turtle Tally UK Project[1] aims to document these wild encounters and encourage people to report them. Not only is it illegal to buy or sell them, but it is illegal to transfer ownership, give them to people or allow them to breed. They must be kept in a secure environment without the possibility of them being able to escape. One big rule is NO taking your terrapin on a walk, even on a lead.
Conservation Status
Unfortunately, some species of terrapins are considered critically endangered including the Northern River terrapin and the Painted terrapin, both native to Southeast Asia. There are many reasons for their critically endangered status; habitat loss, poaching, environmental changes, and the combination of all these factors has led to extremely low breeding populations making recovery difficult. In the world, their habitats are destroyed due to human activity; limiting areas where terrapins can reproduce. We are reducing their egg-laying sites which is causing their numbers to inevitably decrease. In the wild, terrapins can die due to incidental drownings, but also from being captured in fishing gear or being caught in crab traps, which also causes them to drown.
Conclusion
Terrapins may not wear lab coats or fly through space, but they’re little evolutionary marvels all the same- perfectly designed to split their time between land and water. From their streamlined shells to their salt secreting glands, these semi-aquatic reptiles are living proof that nature is the ultimate engineer. Whether basking in the sun or foraging in brackish marshes, these charming reptiles have been tuning its lifestyle for millions of years. Not bad for a turtle with a taste for both surf and turf.