Hello everyone! Today, I will talk about red-eared sliders (RES), a common sight in Singapore’s waters and pet shops. They are commonly sold in pet shops and aquarium shops at a very small size, about 5cm in shell length. Their cute stature, cheap prices (imagine that you cost less than a scoop of ice cream at a cafe) and hardiness lead to their rise in popularity as pets in Singapore. Furthermore, these shelled creatures are viewed as symbols of longevity and stability in Chinese culture.

Single scoop (all flavours) – $3.90

However, many buyers are not aware of the potential size these baby RES can grow to. The situation is worsened by the many profit-driven aquarium shop owners giving misinformation to irresponsible buyers.  I decided to go undercover and pretend to be an irresponsible buyer even though I had encountered many of those instances in my years of visiting aquarium shops. What I uncovered was shocking, to say the least. I went to a local aquarium shop asking for recommendations and advice for keeping a terrapin. The owner suggested I buy one of those premade plastic “turtle enclosures”, which is far from ideal but seems attractive to newcomers to the hobby due to its simplicity. When asked how big these little terrapins can get, he told me it will not get large enough to not fit in its enclosure. This may be partially true. However, it will probably be so cruel and unhealthy for the terrapin. To make matters worse, he proposed that I can release my terrapin into the local waterways after it gets too large for me to house it appropriately. “Reservoir already so many, you release it, let it make friends with the rest” he reasoned in classic Singlish. This interaction with an aquarium shop owner sheds light on the potential root cause of the problem of RES invading our water bodies.

This was the tank the aquarium shop owner recommended to me. The true shoebox apartment, very Singaporean indeed.

Included in the IUCN list of 100 of the World’s Worst Invasive Alien Species, it is no wonder why they are so abundant in Singapore’s water bodies. Their large import numbers and high population densities in urban areas suggest that the release of RES from the pet trade may be a leading factor for their invasiveness (Ng, 2009). Singapore is home to many species of turtles such as the Malayan box turtle and the Malayan flat-shelled turtle, both of which are classified as Vulnerable by IUCN. Sadly, there is a lack of studies proving that the introduction of RES can cause a decline in the population of native turtle species. This may be due to the difficulty of gathering observational data from aquatic habitats and the elusive nature of many native turtle species. I feel that Singapore should do more in terms of educating the public and aquarium shop owners. The sale of this invasive species should also be highly regulated until its effects on the native biodiversity are understood fully, or else we may potentially lose many of our native biodiversity.




Some interesting finds during my weekly aquarium shop trip 🙂

A large sized Malayan box turtle i spotted in a local aquarium shop. Likely wild caught as captive bred specimens are seldom sold at this size.
Albino RES. Are selective breedings for such disadvantageous traits ethical? Probably a topic for next time!


4 thoughts on “Species Spotlight: Red-eared slider”

  1. FYI
    Overall, a GREAT post again.
    I bet it was fun to “go undercover”. But the best is how you relay the results in a way that supports your argument that misinformation contributes to the problem.
    Writing seems better.
    Some in vitro studies by Cadi & Joly (2003, 2004) support the hypothesis that RES reduces fitness of native turtles in Europe – Google “Cadi Joly red eared slider”. Not sure what work has been done since then though – those are the studies I’m most familiar with. But maybe then you can look for papers that cite them and maybe you’ll find authors who followed up with field experiments.

  2. I have a question. Looking at these photos of the type of housing recommended for these RES, I was struck by the fact that they’re made of plastic and then packaged in plastic too.

    How much resources do you think this uses (production and disposal once pet owners realise their once cute baby RES is now a big, stinky turtle) ?

    1. Hello prof! This is a great question. Unfortunately, I am unable to find information about the type of plastic used in such tanks. However, I will be able to give you some insights into the use of plastics in the aquarium trade. Plastics play a huge role in the aquarium trade because it is both waterproof and cheap. The bags the fishes are transported in are transparent plastics. Many of the appliances used in fishkeeping contain a large proportion of plastic. Although glass tanks are still favored by most aquarists, plastic tanks appeal to the newcomers to the hobby as they are cheaper and lighter in weight (making it easy to carry home). One huge problem with plastic tanks is that they scratch easily, especially when they house a decently sized terrapin with hard claws and shells. Therefore owners of such tanks usually change their tanks often, further worsening the problem of excessive plastic waste in our society. Perhaps I can delve deeper into this issue of plastic overuse in the aquarium trade in a future post, thank you for the inspiration!

  3. Thanks for your reply, Minyu.

    Gee, I hadn’t even considered the plastic bags that you buy the animals in.

    FYI, my guess is the plastic tanks are made of polycarbonate (based on my experience working as a vet tech and my feeling that these tanks are probably the same material as what we use for e.g., terraria for tarantulas and lizards). Polycarbonate is that super rigid, clear plastic. And yes, it scratches really easily.

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