Stephen Corran - Curraghs Wildlife Park

Blog: TMNT - new pet mayhem

Posted: 1st November, 2023

Harry Fryer, Senior Reptile Keeper at Crocodiles of the World and Vice Chair of the BIAZA Reptile and Amphibian Working Group, writes about how film-derived trends can affect the pet trade, and even our native ecosystems...

Leonardo, Raphael, Donatello, and Michaelangelo are back, with the new film “Teenage Mutant Ninja Turtles: Mutant Mayhem.” Whilst fictional films such as these are enjoyed by millions around the World there are some very real-world problems that these films may indirectly contribute to. Throughout the TMNT craze, the sales of pet turtles have sky-rocketed when new releases occur. With the release of the new film, we are keen to ensure that this trend does not continue due to the pressure it puts on the animals and the ecosystems around them.

Invasive species are defined as species that are present and destructive in an area that they are non-native. Due to the impulsive purchases of Pond Sliders, there are now populations found throughout the UK. The Pond Slider (Trachemys scripta) is a mid-sized turtle species found native throughout the South-central and Southeastern United States and Northern Mexico. Currently however, populations now exist in all continents except Antarctica. A major cause of this spread is an increased popularity in the pet trade leading to unwanted turtles being released into waterways. These turtles have become very common in the pet trade due to their availability and general hardiness, much like the sewer dwelling brothers on screen. All subspecies of Pond Slider have been listed on the UK government’s list of invasive non-native species since August 2016, meaning the sale, exchange, breeding, and (most importantly) release of these animals is prohibited.

These turtles have directly impacted turtle populations throughout their invasive range; acting as a competitor, disease vector, and even a predator in some cases. However due to the UK having no native turtle species, these turtles become an unmanageable adversary to many aquatic ecosystems. The turtle tally ( is a UK-based citizen science project looking into the presence of these invasive turtles in our waterways. Although this area remains under-researched, these turtles could have an extreme effect on the ecosystems they are being released into. These turtles are omnivorous; however herbivory prevails as they move into adulthood, meaning that the animals in the ponds not only receive a new predator but also a competitor for resources in smaller water bodies. As an example, the protected Great Crested Newt requires pond vegetation to hide from predators and lay their eggs. The destruction of this habitat could lead to further depletion of this species throughout the UK.

Turtles purchased on impulse as a direct result of films such as Teenage Mutant Ninja Turtles are often destined to live a troubled life. All turtle species can be difficult to maintain in captivity, these animals require very specific water parameters (by means of high-quality filtration), correct temperatures, sufficient lighting, and a far more varied diet than most commercial dry foods can allow for.

Although the sale of Pond Sliders is no longer legal in the UK, other turtles remain commercially available, however the same issues will arise with any cold-tolerant species. If you do wish to purchase a turtle, DO YOUR RESEARCH, these are very long-lived animals (upwards of 40 years in captivity) that will outlast most children’s TMNT phase of their lives. These turtles are expensive to care for, and can be extremely messy. Many issues seen with those purchased as pets are related to poor water quality and incorrect heating and lighting, likely due to low-cost, poor quality/inadequate enclosures. These turtles will also not stay the size of a fifty pence coin they were at time of purchase, these guys can reach a shell length of 35cm!

If they become too problematic and a household can no longer maintain the animal, specialist rescue facilities are highly unlikely to take in these unwanted pets , whether this be due to being at capacity, or the laws on moving these animals.  Release into the wild is NOT a viable or legal option, but for some it may be seen as their only choice, so prior research before committing to reptile-keeping really is key to stop the illegal release of non-native turtles.

Many BIAZA zoos house Pond Sliders, but relinquishing animals to a BIAZA collection is not a possibility. The work done by BIAZA collections aims to educate on these issues and also try to save many of the species that may be affected by these turtles in their native ranges. European Pond Turtles (Emys orbicularis) are housed by multiple BIAZA collections, and have been shown to experience direct impacts due to the arrival of these invasive turtles throughout Europe. The Indian Spotted Turtle (Geochlemys hamiltonii) are another at risk species whose population is still declining. This species is seeing multiple threats in the wild; collection for consumption, collection for the pet trade, habitat destruction, and accidental drowning in fishing nets; the addition of these invasive turtles could lead to the species’ extinction.

It’s not all bad news in the chelonian world however… in recent years BIAZA collections have managed to produce some hope for some of the rarer turtle species that suffer continued wild-population decline through habitat-loss and the illegal wildlife trade. In 2017, Bristol Zoo saw success on a 12 year-long project to breed the Endangered keeled box turtle (Cuora mouhotii), producing two animals that hatched out at about 12 grams a piece. In 2021, ZSL London Zoo managed to hatch three Critically Endangered big-headed turtles (Platysternon megacephalum) from adults that had been directly rescued from the wildlife trade. Following on from this, Durrell's Jersey Zoo produce six Madagascan vig-headed turtles (Erymnochelys madagascariensis) in late 2022, rounding out the breeding of at risk (and apparently obnoxious) large headed species.

Despite the efforts of these and many other BIAZA institutions, more than half of the World’s turtle and tortoise species remain threatened, so we urge caution when thinking about committing to a turtle as a pet. Why not just watch the film and pick up an action figure or cuddly toy?


- Harry Fryer, Vice Chair BIAZA Reptile and Amphibian Working Group and Senior Reptile Keeper at Crocodiles of the World


All blogs reflect the views of their author and are not a reflection of BIAZA's positions. 

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