The Vietnamese Black-breasted Leaf Turtle
An animal’s eyes have the power to speak a great language. Perhaps when philosopher Martin Buber spoke those words, he had the striking white iris of the Vietnamese black-breasted leaf turtle (Geoemyda spengleri) in mind. This small turtle is truly a “cult classic,” and many turtle hobbyists hold a special place in their hearts for this enigmatic little creature. Keepers surely know the species’ lay-in-wait look during feeding time, when G. spengleri seems to look up at you with one eye while the other scans the floor of its enclosure for food. Research has indeed shown that G. spengleri can watch two subjects at the same time—an ability known as “independent accommodation.” Throw a tasty earthworm into the enclosure, and both eyes will immediately become fixed on the prey (this is “coupled accommodation”).
Geoemyda spengleri is an endangered species that naturally occurs in southeastern China and northern Vietnam, in unfragmented, mountainous forests. It has adapted to live in areas of relatively high elevation, usually on sloped terrain and often in close proximity to (but not in) freshwater streams. It lives in deciduous forests, beneath trees that shed their leaves in the winter, and which surely block out much of the sun during warmer months. Perhaps this shady habitat led in part to the development of the species’ distinctive, owl-like eyes.
The Vietnamese black-breasted leaf turtle is one of the smallest turtles in the world. Adults usually attain just 7 to 11 centimeters in length and 90 to 125 grams in weight for males and 150 to 190 grams for females (hatchlings are 3 to 3.5 centimeters and weigh just 6 to 7.5 grams).
Its common name is due to the black coloration that covers most of the plastron, while the carapace resembles a fallen leaf in both shape and color. Sexual dimorphism is present, with males having a more elongate shell, a concave plastron and much larger tail. Identifying sexual characteristics can appear early on, with some turtles appearing male at sizes as small as roughly 25 grams. Some keepers begin looking at shell shape, tail size, the shape of scales on forelimbs, and especially iris color (males have stunning white irises), as early indicators of gender in young turtles.
An important decision for potential G. spengleri keepers, especially in regard to adult turtles, is whether to keep animals separately or in communal enclosures. There are pros and cons with each option. When kept separately, enclosures can be on the small side, an obvious plus for anyone with limited space. And turtle’s husbandry needs are very easy to provide, and it can be kept indoors at room temperature.
At the TurtleRoom, we choose to keep our adults individually. One reason is because doing so gives females a break from male advances, and this helps ensure every animal is eating and living as stress free as possible. Also, it’s easier to keep track of health and parentage when keeping turtles separately, and both should be at the top of a keeper’s priority list when working with this (and any) endangered species.
An 18-gallon Rubbermaid tub measuring approximately 25¼ inches long by 17 inches wide and 15¼ inches tall can provide an excellent home for a single adult G. spengleri. In addition to being large enough for this small—and also not very active—species, the opaque walls of the tub will help reduce stress because they will shield the occupants from any potentially stressful (to them) activity in the room where they’re being kept. The height of the walls also helps to maintain high humidity, which is an important component of proper husbandry for these turtles.
When housing multiple turtles together care must be taken to ensure that subordinate animals are not kept from resources such as hides and water and food dishes. To play it safe, provide as many of each of these resources as there are inhabitants. Use décor such as logs, rocks, hides, plants and even inclines in substrate to provide “sight breaks” to prevent animals from seeing each other constantly. This can help the turtles feel safe, because as much as we would like to think that they need friends with which to cohabitate, other turtles are often a significant stressor.
Up to four adults could be a kept in a small Waterland turtle tub, but males are rare and could fall victim to having their sexual organs severed by other turtles while mating in a communal setting.
Those who choose to keep G. spengleri in communal habitats are known to create some beautiful naturalistic enclosures. A variety of live plants can be used, which will be appreciated as shelter and help to maintain high humidity. These, coupled with small pill bugs or springtails, can be part of a living vivarium that breaks down waste on its own. The bugs can be purchased online, but usually show up on their own in indoor enclosures. Uneaten earthworms may also be left to inhabit such an enclosure, and will survive for long periods of time.
Geoemyda spengleri can be kept on a substrate mixture of organic topsoil, peat moss and cypress mulch. The topsoil and cypress mulch retain moisture and help increase overall humidity of the terrarium, while peat moss lowers ph and wards of mold that may grow in damp areas. Oak leaves can be used in enclosures to help reduce stress, as the turtles will hide beneath them. After all, one would think that a turtle shaped like a leaf would do well in a situation where they could hide among fallen leaves. We also use clay pot halves and cork bark rounds as hides in adult enclosures, and hides, substrate, logs or rocks can all be arranged to provide “look-out” areas where G. spengleri can rest and observe their surroundings partially hidden and without feeling stressed.
Frequent misting of the enclosure, at least daily, is suggested, and a drainage layer will allow the substrate to remain moist, but not oversaturated. Many plants commonly available as houseplants, including most ferns, peace lilies and pothos ivy, will do well in Geoemyda enclosures. Pothos is listed on many toxic plant lists, possibly due to it being high in oxalates. This might pose a threat to a species that would devour a large plant, but G. spengleri will not eat plants in their enclosures.
Basking heat sources are not as important for this species as proper humidity levels. The importance of UVB is also unknown, as Vietnamese black-breasted leaf turtles, as mentioned, live under heavy canopy in the wild. Some keepers do not keep their animals with a UVB light overhead, though many do, simply for peace of mind. We use a UVB strip light over all of our G. spengleri enclosures for that very reason. Basking lights and temperatures are not as important as with other species. If the ambient room temperature is appropriate, the turtles should fair well.
It is widely believed that G. spengleri should be kept between 68 and 80 degrees Fahrenheit. We generally maintain ours above 60 and below 85 degrees, though both adults and juveniles experience temperatures within a much larger range, allowing for daily and seasonal fluctuations. They have experienced temperatures in the mid 90s temporarily during the summer and temperatures in the 40s during the winter, both with no ill affect. When these turtles are exposed to temperatures below the mid 60s, they slow down greatly, sometimes not moving for weeks. Extreme temperature fluctuations, however, coupled with a healthy diet rich in fruit, seem to play an important role in producing healthy hatchlings.
Geoemyda spengleri can be fed a mixture of live food, turtle pellets, fruits and a lean meat mixture. Most often, live prey items, such as earthworms, crickets, snails, slugs, and pill bugs, are appreciated greatly. The meat mixture we use is a combination of lean ground turkey, chicken feed and finely chopped carrots.
Pellets can be offered in a dish mixed with chopped fruit. This species seems to prefer over-ripened fruit that is red in color. Our animals accept strawberries, grapes, blueberries, bananas, watermelon, and tomatoes. Many keepers report their turtles’ unwillingness to accept fruit and even pellets. As with any picky eaters, a bit of tough love may sometimes be necessary. We have had our animals go as long as two weeks without food in the warmer months, and this species can easily go two or three months without eating in the winter months. We have yet to experience an animal that will not accept pellets and fruit after such a lengthy wait.
Of interest is the fact that most keepers with breeding adults report that their animals accept fruit. While there is no evidence other than observation regarding the correlation between the two, it seems adult Vietnamese black-breasted leaf turtles that do not accept fruit may be at a higher risk of not successfully reproducing.
Breeding, Incubation and Hatchling Care
Breeding G. spengleri is relatively straightforward, providing you have healthy adults. When kept separately, males will run toward females seconds after being introduced. Breeding is not as violent as with many chelonian species, but it is as ardent as with any turtle.
Geoemyda spengleri does not lay many eggs, usually one or two per clutch, as many as three times a year. Three egg clutches have been reported, but this is very rare. Artificial incubation takes at least 70 days and can be done at fluctuating room temperatures. Cooler temps extend the incubation period. We have had an egg incubate for as long as 111 days, and an AZA-accredited zoo reported incubation lasting as long as 135 days. Many seasoned keepers believe that such fluctuation in incubation temperatures helps to produce larger, stronger hatchlings.
It is said that G. spengleri eggs will die if exposed to temperatures above 80 degrees. We have had eggs temporarily reach temperatures as high as 92 degrees with no issues, although the higher temperatures were not sustained for long periods, and it is more likely that prolonged temperature extremes will cause more harm.
It has been reported that males of this species fared far worse during the days of large-scale importation, usually succumbing to illness more quickly than their female counterparts. Regardless of the reason for the shortage for males, the truth is that we have a real mystery that needs to be solved. Both the American and European populations of G. spengleri are in dire need for males to be produced. Additionally, only a very small amount of the few males that have been produced in captivity have actually sired captive offspring themselves.
This lack of males has led to many keepers incubating eggs at lower temperatures, even though, as of this writing, it has not been proven that G. spengleri experience temperature-dependant sex determination (TSD). If TSD does occur with this species, it is likely that gender determination happens during a very small window during incubation. And because most keepers use fluctuating room temperatures to incubate their eggs (doing so usually results in very successful incubation), it can be entirely difficult to monitor temperatures that might affect gender. That said, I recommend that anyone breeding this species should strive to provide incubation temperatures between 68 and 74 in the hope of producing males.
We keep hatchling G. spengleri in Sterilite tubs filled with sphagnum moss and an inch of water in the bottom (this somewhat more aquatic environment is used for its ability to maintain a high humidity level). A vine of pothos ivy is included for the turtles to hide under; one half of a small plastic flowerpot (cut in half vertically) provides an additional hide. Temperatures for hatchlings are maintained within the high 70s.
Hatchling G. spengleri will eat a diet similar to the adults. To start hatchlings, smaller worms should be chopped into small, manageable pieces, as moving prey is always much more appreciated. Pellets and fruit may be offered as well, but pellets may not be eaten and fruit will almost certainly be refused. We have had some new hatchlings refuse to eat for more than a month. On the other hand, our records for the quickest to feed are at four days for chopped earthworms and nine days for pellets.
Great Pet Turtles
When G. spengleri can be found for sale, it is worthy of serious consideration by any turtle keeper. The opportunity attached to this species for keepers to develop elaborate, living vivariums is a bonus usually only available to keepers of smaller herps, such as dart frogs and geckos. This is in addition to the small adult size and very minimal heat and lighting requirements for this species.
Unfortunately, the asking price for Vietnamese black-breasted leaf turtles has inflated greatly over the past decade. While adults could at one time be purchased for $10 or less—being fresh imports that usually died soon after purchase—captive-bred hatchlings today could cost between $500 and $800. The optimistic view for this is recognizing the fact that freshly imported animals are no longer offered in the U.S. legally, thanks to international protection under CITES. However, it is legal to acquire this species in any state in the U.S., and captive-hatched specimens are available.
Many breeders are willing to make connections with potential buyers, ultimately selling to their contacts before ever letting their offspring hit the open market. Therefore, it is wise to network and get to know these breeders. Doing so can lead to years of meaningful turtle keeping and camaraderie with fellow Geoemyda spengleri enthusiasts!
Anthony Pierlioni is the assistant director of theTurtleRoom (https://theTurtleRoom.com), an official conservation partner of the Association of Zoos and Aquariums. He maintains the only private group of AZA Species Survival Plan-listed Geoemyda spengleri and recently wrote a book on the Geoemyda species as a whole, as part of Living Art Publishing’s Turtles of the World series. He is also the co-host of The Pondcast, an online show dedicated to reptiles and amphibians and the people who love them.