| Asian leaf turtles | |
|---|---|
 | |
| A youngCyclemys dentata fromJava,Indonesia. | |
Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Order: | Testudines |
| Suborder: | Cryptodira |
| Family: | Geoemydidae |
| Subfamily: | Geoemydinae |
| Genus: | Cyclemys Bell, 1834 |
| Type species | |
| Cyclemys orbiculata Bell, 1834 | |
| Species | |
7 sp., seetext | |
 | |
| Distribution ofCyclemys: The exact range of individual species is uncertain.[1] | |
Cyclemys is agenus of freshwaterturtles, commonly referred to asAsian leaf turtles, from the familyGeoemydidae. The genus occurs throughoutSoutheast andSouth Asia, and currently contains sevenspecies.
Asian leaf turtles average 25 cm (9.8 in) in length. They are mostly brown to greenish in color, with round to rectangular shells. Theircarapaces bear a superficial resemblance toplant leaves, hence theircommon name. They can be found around shallow, slow-moving bodies of water in hilly forests. Adults are primarilyterrestrial, thoughjuveniles are moreaquatic.
Cyclemys turtles belong to thefamilyGeoemydidae under thesubfamilyGeoemydinae. They were first described in 1834 by EnglishzoologistThomas Bell in his workA Monograph of the Testudinata.[2][3]Cyclemys and closely related genera (Cuora,Pyxidea, andNotochelys) are believed to have diverged from a commonHeosemys-like ancestor.[4][5][6]
Cyclemystaxonomy andphylogeny have been historically difficult to ascertain due to themorphological similarity between species, as well as changes in the color patterns during growth.[7] Until recently, the genus was thought to comprise only one or two morphologically variable species,C. dentata andC. oldhamii.[1][8] Subsequent investigation has now put the number of species under the genus to seven, though this remains controversial. The status ofC. enigmatica as a valid species is contested, as is the recognition ofC. atripons andC. pulchristiata, both of which are nearly impossible to tell apart morphologically.[1][9]
Previously recognized species,C. tcheponensis ( =C. tiannanensis) andC. shanensis, have been merged intoC. oldhamii followingmtDNA sequencing. The conclusions of which showed that the morphological differences between them (the presence or absence of neck/head stripes, and hatchling color patterns) were not enough to classify them as separate species.[1]C. ovata has been similarly subsumed intoC. dentata.[10]
The two distinct morphological differences betweenCyclemys species are based on the main color of theirplastrons - species with yellow bellies (C. atripons,C. dentata, andC. pulchristiata), and species with dark bellies (C. enigmatica,C. fusca,C. gemeli, andC. oldhamii).[1]
Synonyms ofCyclemys (ex errore) include:CyclemusLi,CyclemisGood, andCyclemyMao.[11]
The generic nameCyclemys comes from theGreekκύκλος (kyklos, meaning 'round' or 'circle', referring to the shape of thecarapace) andεμύς (emys; 'freshwater turtle').[12] They are known under thecommon nameAsian leaf turtles or simplyleaf turtles, again because of the appearance of their carapaces. They share the collective name 'leaf turtles' with turtles of the genusGeoemyda, as well as turtles with 'leaf' in their names, such as the Annam leaf turtle (Mauremys annamensis), among others.[12][13] 'Asian leaf turtle' is also the specific common name ofC. dentata.
Cyclemys turtles are characterized by more or less roundcarapaces, which are typically dark green, brownish, tan, or olive in color. The shell may have a prominent vertebralkeel running from head to tail. Serrated marginalscutes are common in juveniles. In adults, only the posterior marginalscutes are serrated.[14]
Adults ofCyclemys also develop a joint in the middle of their plastrons (known as a plastral hinge), enabling them to articulate the front and rear halves to some extent. Unlike the closely relatedCuora, which can completely close its shell because of the hinge,[15]Cyclemys plastral hinges only close the shell partially.[6][16] The plastral hinge may also play a significant role in facilitating egg-laying in adult females.[13]
A distinguishing characteristic of the genus is the secondary division of the abdominal scutes (the middle pair of scutes in the plastron) due to the development of the plastral hinge as the turtle matures. It eventually leads to the formation of small triangular additional scutes between the abdominal and pectoral scutes.[17]
Cyclemys turtles arecryptodires, having the ability to pull their heads straight back and vertically into their shells instead of folding them sideways likepleurodires. The head varies between species from dull to striped with bright red or orange bands of color. The plastron can have a dark or light (tan to yellow) background which can be uniform or patterned with fine lines radiating from the center of each plastral scute.[14]
Their feet are partially webbed and well developed for either aquatic or terrestrial mobility. They can grow to about 25 cm (9.8 in) in length.[12]
Cyclemys species achieve sexual maturity after seven to 12 years, earlier for males and later for females.[14][18]Sexual dimorphism is apparently mostly absent, though females are likely to outgrow males.[1][19] Females usually deposit 10 to 15 eggs per clutch.[13]
AC. dentata individual has been recorded living up to 14.7 years in captivity.[20] However, an adult specimen caught in the wild has also been recorded living another 14 years, making it likely that the maximum lifespan ofCyclemys species has been underestimated.[21]
The distribution ranges of individual species ofCyclemys remain unclear, but the genus occurs inSouth Asia andIndochina (Vietnam,Myanmar,Laos,Cambodia,Myanmar,Thailand, central to southernChina,Bangladesh,Nepal, and northeasternIndia), as well as the Southeast Asian countries ofMalaysia,Indonesia,Brunei, and thePhilippines.[1]
Adults spend most of their time on land. They can be found near ponds, streams, and other shallow, slow-moving bodies of water in hilly forests.[12][13] Although more common in lower elevations, they have been found in higher elevations exceeding 1,000 m (3,300 ft)above sea level.[22]
They areomnivorous,[23] but juveniles tend to be morecarnivorous. Because their prey are typically aquatic, the younger turtles are found in water more often than adults.[12]
The species are listed alphabetically along with common names, identifying adult characteristics, and known geographical distribution.[11] They are divided into two morphologically distinct groups.[1]
Several species previously classified underCyclemys –C. amboinensis,C. flavomarginata,C. mouhotti, andC. trifasciata – are now classified under the genusCuora.C. annandalii is now classified underHeosemys,C. annamensis underMauremys, andC. giebelii asNotochelys platynota.[10]
Cyclemys species are often caught and sold for the pet trade, food, ortraditional medicine.[24] On August 25, 1998, Forest Protection authorities ofVietnam confiscated a shipment of about 700 turtles with an estimated 30 individuals ofC. oldhamii.[25] In May 2007, more than 3000 individuals ofCyclemys, along withAsian box turtles, were confiscated in hundreds of crates inYangjiang, China.[26]
The most commonly encountered species ofCyclemys in the pet trade,C. dentata, is now beingcaptive bred. They are usually preferred, as they are healthier, more acclimated to handling, and captive breeding minimizes the impact on wild populations.[12][27]
The confusion over their exact taxonomy and distribution led to an incomplete assessment of their conservation status by theIUCN.[8] In 1991, with only two species recognized,Cyclemys was given the Action Plan Rating of 3 - in need of some conservation action.[28] In the last assessment in 2000 by the Asian Turtle Trade Working Group of IUCN, the different species currently recognized under the genusCyclemys were treated as all belonging to the speciesC. dentata. This resulted in the current incorrect classification of all of the species aslower risk/near threatened.[8] Until now, the true conservation status, the actual effects ofwildlife trade, deforestation, and habitat loss on individualCyclemys species, have yet to be studied.[14][22]
FamilyGeoemydidae | ||||
|---|---|---|---|---|
| ||||
| Genera |
|  | ||
| †Banhxeochelys | ||||
| Batagur | ||||
| Cuora | ||||
| Cyclemys | ||||
| †Echmatemys | ||||
| Geoclemys | ||||
| Geoemyda | ||||
| Hardella | ||||
| Heosemys | ||||
| Leucocephalon | ||||
| Malayemys | ||||
| Mauremys | ||||
| Melanochelys | ||||
| Morenia | ||||
| Notochelys | ||||
| Orlitia | ||||
| Pangshura | ||||
| Rhinoclemmys | ||||
| Sacalia | ||||
| Siebenrockiella | ||||
| Vijayachelys | ||||
Phylogenetic arrangement of turtles based onturtles of the world 2017 update: Annotated checklist and atlas of taxonomy, synonymy, distribution, and conservation status. †=Extinct. | ||||