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The Cochin forest cane turtle (''Vijayachelys silvatica''), also known as Kavalai forest turtle, forest cane turtle or simply cane turtle, is a rare
turtle
Turtles are an order of reptiles known as Testudines, characterized by a special shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked t ...
from the
Western Ghats of
India
India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...
. Described in 1912, its
type locality is given as "Near
Kavalai in the
Cochin
Kochi (), also known as Cochin ( ) ( the official name until 1996) is a major port city on the Malabar Coast of India bordering the Laccadive Sea, which is a part of the Arabian Sea. It is part of the district of Ernakulam in the state of K ...
State Forests, inhabiting dense forest, at an elevation of about 1500 feet above sea level".
[Henderson (1912)] Only two specimens were found at that time, and no scientist saw this turtle in the next 70 years. It was finally rediscovered in 1982, and since then a number of specimens have been found and some studies have been conducted about its affiliation and habits.
[Praschag et al. (2006)]
Like its relatives, it belongs to the
subfamily Geoemydinae
The Geoemydinae are a subfamily of turtles consisting of 60 subspecies and 76 taxa.
These genera are placed here:
* ''Batagur'' (six species, including part of Kachuga)
* '' Chinemys'' (three species) (sometimes included in ''Mauremys'')
* '' C ...
of the
family
Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...
Geoemydidae
The Geoemydidae (formerly known as Bataguridae) are one of the largest and most diverse families in the order Testudines (turtles), with about 70 species. The family includes the Eurasian pond and river turtles and Neotropical wood turtles. Mem ...
, formerly known as Bataguridae. It was once placed in the
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...
''
Geoemyda
''Geoemyda'' is a genus of freshwater turtles in the family Geoemydidae (formerly Bataguridae). It contains two species:Heosemys
''Heosemys'' is a genus of freshwater turtles ("terrapins" in British English) in the family Geoemydidae (formerly called Bataguridae). The genus ''Heosemys'' was split out of the related genus ''Geoemyda'' by McDowell in 1964.
Species
Four sp ...
''. But as it seems, the Cochin forest cane turtle forms a quite distinct lineage closely related to ''
Melanochelys
''Melanochelys'' is a genus of turtles in the family Geoemydidae. Members are found in India, Myanmar, Bangladesh, Sri Lanka and Nepal.
Species
''Melanochelys'' contains only two species:
* Indian black turtle
The Indian black turtle (''Melan ...
''. Thus, nowadays it is recognized as a
monotypic
In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispe ...
genus, named ''Vijayachelys'' in honor of the famous Indian
herpetologist
Herpetology (from Greek ἑρπετόν ''herpetón'', meaning "reptile" or "creeping animal") is the branch of zoology concerned with the study of amphibians (including frogs, toads, salamanders, newts, and caecilians ( gymnophiona)) and rep ...
Jagannathan Vijaya (1959–1987) who rediscovered this species in 1982 and until her death extensively studied it. A diagnosis of the
osteology of ''Vijayachelys'' was published in 2006.
Description
The
carapace is considerably depressed, with a prominent mid-line keel, as well as one less pronounced
lateral
Lateral is a geometric term of location which may refer to:
Healthcare
*Lateral (anatomy), an anatomical direction
* Lateral cricoarytenoid muscle
* Lateral release (surgery), a surgical procedure on the side of a kneecap
Phonetics
*Lateral co ...
keel on each side. Its posterior margin is feebly reverted and not or only indistinctly serrated. The nuchal
scute
A scute or scutum (Latin: ''scutum''; plural: ''scuta'' "shield") is a bony external plate or scale overlaid with horn, as on the shell of a turtle, the skin of crocodilians, and the feet of birds. The term is also used to describe the anterior po ...
is small. The first vertebral scute is broader in front than behind and larger than the second, third and fourth vertebral shields. These are considerably broader than long, as broad as the costal scutes.
[Henderson (1912), Praschag et al. (2006)]
The
plastron is sizeable, being nearly as large as the shell opening; it is connected to the carapace by
ligaments and particularly in females there is little
ossification
Ossification (also called osteogenesis or bone mineralization) in bone remodeling is the process of laying down new bone material by cells named osteoblasts. It is synonymous with bone tissue formation. There are two processes resulting in ...
between the shields of the shell. The plastron is angled at the sides and openly emarginate at the forward and aft opening. The width of the plastron bridge is less than the length of the hind lobe; the longest
median suture is between the abdominal scute, the shortest between the gular scute. The axillary and inguinal scutes are very small; one of the latter is even absent.
![CaneTurtle DSC 4117](https://upload.wikimedia.org/wikipedia/commons/6/6a/CaneTurtle_DSC_4117.jpg)
Its head is rather large, with a truncated snout as long as the sizeable
orbit
In celestial mechanics, an orbit is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an object or position in space such as ...
; the upper jaw is hooked, with small
premaxilla
The premaxilla (or praemaxilla) is one of a pair of small cranial bones at the very tip of the upper jaw of many animals, usually, but not always, bearing teeth. In humans, they are fused with the maxilla. The "premaxilla" of therian mammal has ...
e. The
mandibular
In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower tooth, teeth in place. The mandible sits beneath the maxilla. It is the only movabl ...
symphysis
A symphysis (, pl. symphyses) is a fibrocartilaginous fusion between two bones. It is a type of cartilaginous joint, specifically a secondary cartilaginous joint.
# A symphysis is an amphiarthrosis, a slightly movable joint.
# A growing togethe ...
is very long, exceeding the maximum diameter of the orbit in width. On the hind part of the head, the skin is divided into moderately large shields. The
skull
The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, th ...
lacks a
temporal arch and has the
frontal bone
The frontal bone is a bone in the human skull. The bone consists of two portions.'' Gray's Anatomy'' (1918) These are the vertically oriented squamous part, and the horizontally oriented orbital part, making up the bony part of the forehead, pa ...
extended to form a considerable part of the orbit. Seen from above, the
prootic extends towards the front. The
jugal
The jugal is a skull bone found in most reptiles, amphibians and birds. In mammals, the jugal is often called the malar or zygomatic. It is connected to the quadratojugal and maxilla, as well as other bones, which may vary by species.
Anatomy ...
does not contact the small laterally emarginated and medially constricted
pterygoid process
The pterygoid processes of the sphenoid (from Greek ''pteryx'', ''pterygos'', "wing"), one on either side, descend perpendicularly from the regions where the body and the greater wings of the sphenoid bone unite.
Each process consists of a me ...
, the bones being separated by the maxilla and a gap. The triturating (chewing) surface of the upper jaw is long and narrow, more than four times as long as it is wide. The lower
temporal fossa
The temporal fossa is a fossa (shallow depression) on the side of the skull bounded by the temporal lines and terminating below the level of the zygomatic arch.
Boundaries
* Medial: frontal bone, parietal bone, temporal bone, and sphenoid bon ...
is large and strongly
concave
Concave or concavity may refer to:
Science and technology
* Concave lens
* Concave mirror
Mathematics
* Concave function, the negative of a convex function
* Concave polygon, a polygon which is not convex
* Concave set
* The concavity of a ...
, providing an attachment for the massive chewing muscle.
The forelegs are covered in enlarged squarish or pointed horny scales, particularly on the front. The hindlimbs are rather club-shaped, the
anterior margins and anterior region of their heels bearing enlarged horny scales. The fingers are webbed one-third of their length, while the toes bear rudimentary webbing only. The tail is rather short and becomes very narrow behind the
cloaca in males; it is a mere stub in females.
The carapace of the
type specimen
In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralizes th ...
was dark bronze; the plastron yellowish with two dark blotches on either side of the bridge. The jaws and upper front part of the head are bright yellow in the living animal, with a red spot on the top of the snout. The hind part of the head and the neck are brown. Limbs and tail are black.
The length of the type specimen's shell is 120 mm, its breadth 83 mm and its depth 45 mm. Females are slightly larger than males, but this smallish turtle does not seem to exceed about 13 cm in carapace length even when fully grown.
Ecology
![CaneTurtle DSC 3810](https://upload.wikimedia.org/wikipedia/commons/c/c9/CaneTurtle_DSC_3810.jpg)
This turtle inhabits dense evergreen forest, presumably at lower elevations. According to the natives from whom Dr. Henderson obtained the type, the species inhabits short burrows underground and is indifferent about having water nearby (unlike some of its relatives, which are decidedly aquatic). The type as well as another younger specimen were kept in captivity for six months, and Dr. Henderson remarks that they did not show any special partiality for water and when handled did not emit the offensive odour known from the related
Indian black turtle
The Indian black turtle (''Melanochelys trijuga'') or Indian pond terrapin is a species of medium-sized freshwater turtle found in South Asia.
Description
Despite its name, the color of its upper shell or carapace can vary from reddish to dar ...
(''Melanochelys trijuga'').
The first captive specimens lived entirely upon vegetable food, but subsequently it has turned out that this turtle is
omnivorous
An omnivore () is an animal that has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize the nut ...
, eating any suitably sized plant and animal food.
Conservation
The Cochin forest cane turtle is listed as endangered (EN B1+2c v2.3) by the
IUCN and is listed in
CITES Appendix II
CITES (shorter name for the Convention on International Trade in Endangered Species of Wild Fauna and Flora, also known as the Washington Convention) is a multilateral treaty to protect endangered plants and animals from the threats of interna ...
.
[ It is rarely found in the pet trade. The Kadar tribe people occasionally hunt the turtles for bush meat. Additional threats are posed by deforestation and planned hydroelectric projects. The turtles have a patchy distribution range but where they occur they can be found in relatively high densities. Still, this turtle is considered to be a rare species.][Vijayachelys silvatica (Henderson 1912) – Cochin Forest Cane Turtle. In: Rhodin, A.G.J., Pritchard, P.C.H., van Dijk, P.P., Saumure, R.A., Buhlmann, K.A., Iverson, J.B., and Mittermeier, R.A. (Eds.). Conservation Biology of Freshwater Turtles and Tortoises: A Compilation Project of the IUCN/SSC Tortoise and Freshwater Turtle Specialist Group. Deepak, V., Praschag, P., and Vasudevan, K. No. 5, pp. 078.1–7 Chelonian Research Monographs.]
Footnotes
References
* Groombridge, B.; Moll, Edward O. & Vijaya, Jaganath (1983): Rediscovery of a rare Indian turtle. ''Oryx
''Oryx'' is a genus consisting of four large antelope species called oryxes. Their pelage is pale with contrasting dark markings in the face and on the legs, and their long horns are almost straight. The exception is the scimitar oryx, which ...
'' 17 (3): 130–134.
* Henderson, J.R. (1912): Preliminary note on a new tortoise from South India. ''Records of the Indian Museum'' 7 (21): 217–218.
* Moll, Edward O.; Groombridge, B. & Vijaya, Jaganath (1986): Redescription of the cane turtle with notes on its natural history and classification. ''Journal of the Bombay Natural History Society
The ''Journal of the Bombay Natural History Society'' (also ''JBNHS'') is a natural history journal published several times a year by the Bombay Natural History Society. First published in January 1886, and published with only a few interruptio ...
'' 83 (Supplement): 112–126.
* Praschag, Peter; Schmidt, Christian; Fritzsch, Guido; Müller, Anke; Gemel, Richard & Fritz, Uwe (2006): ''Geoemyda silvatica'', an enigmatic turtle of the Geoemydidae (Reptilia: Testudines), represents a distinct genus. ''Organisms Diversity & Evolution'' 6 (2): 151–162. (HTML abstract). Erratum: ''Organisms Diversity & Evolution'' 6 (2): 254. (HTML abstract)
* Sharath, B.K. (1990): On the occurrence of the forest cane turtle (''Geoemyda silvatica'') in the Western Ghats of Karnataka, South India. '' Hamadryad'' 15 (1): 34.
* Smith, M.A. (1941): ''The Fauna of British India, Including Ceylon and Burma
''The Fauna of British India'' (short title) with long titles including ''The Fauna of British India, Including Ceylon and Burma'', and ''The Fauna of British India Including the Remainder of the Oriental Region'' is a series of scientific books th ...
: Reptilia and Amphibia''.
* Vijaya, Jaganath (1982): Rediscovery of the forest cane turtle (''Heosemys silvatica'') of Kerala. '' Hamadryad'' 7 (3): 2–3.
* Vijaya, Jaganath (1983): Rediscovery of the Forest Cane Turtle, ''Heosemys'' (''Geoemyda'') ''silvatica'' (Reptilia, Testudinata, Emydidae) from Chalakudy Forests in Kerala. ''Journal of the Bombay Natural History Society
The ''Journal of the Bombay Natural History Society'' (also ''JBNHS'') is a natural history journal published several times a year by the Bombay Natural History Society. First published in January 1886, and published with only a few interruptio ...
'' 79 (3): 676-677
* Vijaya, Jaganath (1988): Status of the forest cane turtle (''Geoemyda silvatica''). '' Hamadryad'' 13 (2): 10
{{Taxonbar , from1=Q14566124 , from2=Q1499407
Vijayachelys
Turtles of Asia
Reptiles of India
Endemic fauna of the Western Ghats
Cane
Cane or caning may refer to:
*Walking stick or walking cane, a device used primarily to aid walking
* Assistive cane, a walking stick used as a mobility aid for better balance
*White cane, a mobility or safety device used by many people who are ...