by Nick Vadala
When it comes to how long turtles live, the answers can be elusive. However, as potential pet owners should know, most species are generally able to live for decades and could potentially serve as a near-lifelong family member. After all, for many species, scientists and researchers are unable to pin down an exact lifespan.
“In most cases, many of the aquatic turtle species—including Red-Eared Sliders and Painted Turtles—theoretically can live into their 40s,” says Dr. Mark Mitchell, researcher and professor of zoological medicine at the University of Illinois. “They could potentially live longer, but we just don’t have records.”
Other popular pet turtle species, like African Sideneck Turtles and Map Turtles, are generally expected to live 25 years or more. Meanwhile, terrestrial box turtles, which are illegal to breed or keep as pets in more than 20 states, have a potential lifespan of up to 100 years, and an average longevity of 40 to 50 years in captivity.
Several decades ago, however, that long lifespan expectation for pet turtles wasn’t necessarily the case. In Mitchell’s estimation, many turtles back then likely lived just 4 to 6 years in captivity due to improper care. Now, as our understanding of how to properly care for turtles has grown, we are seeing those decades-long lifespans that make pet turtles such a commitment.
“Historically, people just left them at room temperature,” Mitchell says, “which, with turtles being ectotherms [animals that depend on external sources of body heat], would alter their appetites, and the animals just wouldn’t thrive. They’d be more susceptible to infections.”
A poor diet along with improper lighting never allowed them to live well and grow to their full capacity.
Other Turtle Species With Long Lifespans
Other species of wild turtles and tortoises have even longer lifespans than pet turtles. Some tortoises can reach or surpass 100 years in terms of their longevity, with sea tortoises approaching similar numbers. Dr. Mitchell has worked with sea turtles in the past, and he points out that estimating how long sea turtles live is as good an estimation as that of pet turtles’ lifespans. True estimates are hypothetical at best.
“Theoretically, sea turtles may be able to top the century mark,” he says. “But without good data, it’s hard to tell.”
Why Do Turtles Live So Long?
Why turtles live so long also tends to be somewhat of a mystery. One element that seems to play a large role, however, is turtles’ relatively slow metabolism, which helps them process things like diseases and aging at a different rate from birds or other domestic pets. It also helps them live for extended periods without food or water.
In turn, turtles are able to enter states of brumation and aestivation, hibernation-like states during hot and cold temperature extremes. During those times, water turtles can live underwater for months without access to oxygen, which some researchers believe plays a key role in how turtles’ bodies are able to process the stress of a decades-long lifespan.
“Everything’s a bit slower for them,” Mitchell says. “They can undergo anaerobic metabolism, which allows them to process things at a different rate.”
One 2013 study published in the scientific journal Genome Biology, decoded the genome of a western painted turtle, finding some 19 genes in the brain and 23 in the heart that are activated in low-oxygen conditions. Together, those genes work to protect turtles’ organs from oxygen deprivation, and could, as the study posits, potentially provide an increase in how long turtles live.
How to Help Pet Turtles Live Longer
The biggest factor in achieving a long lifespan for pet turtles is proper care. As Mitchell notes, that care begins first and foremost with temperature. Turtles’ water temperature should clock in between 78 to 82 degrees, and pet parents should provide a slightly warmer basking area of 80 to 85 degrees or more for some species.
“Make sure they have an appropriate temperature gradient,” he says. “Providing that temperature basically controls their metabolism.”
In conjunction with a proper heat source, turtles should also have access to a light source that provides UVA and UVB ultraviolet light, along with an area for basking and shelter to help minimize stress. Additionally, Mitchell recommends the use of turtle tank filters on the tank’s aquatic components to keep out toxins like ammonia. The enclosure itself also plays a role, and owners should expect to purchase larger glass enclosures as their turtles grow.
Diet is another important factor. Dr. Mitchell advocates a combination of commercially available turtle food and greens such as romaine lettuce or dandelion greens as a way to balance a pet turtle’s diet. Treats can be things like earthworms, small fish, shrimp, or other aquatic invertebrates. Depending on the species of turtle, the nutritional requirements may vary.
With those elements in place, your turtle can more easily thrive and live out its full potential lifespan—however many years that may be.
Genome Biology, 2013, 14:R28; Shaffer et al.