The Cylindrophiidae are a monotypic family[2] of secretive, semifossorial, non-venomous snakes containing the genus Cylindrophis found in southeastern Asia. These are burrowing snakes and most have a banded pattern on the belly.[3] Currently, 13 species are recognized, all with no subspecies.[2] Common names include Asian pipe snakes or Asian cylinder snakes.
Cylindrophis are found in southeastern Asia from Myanmar, Laos, Vietnam, Cambodia, Thailand, and the Malay Archipelago, including Singapore, both peninsular Malaysia and Sarawak, and Indonesia, including the Greater Sunda Islands (Borneo [including Sarawak and Brunei]), Sumatra, and Java, as well as some of their offshore islands), Sulawesi, the Lesser Sunda Islands (Lombok, Komodo, Flores, Sumbawa, Timor [including Timor-Leste]), and east to the Maluku Islands (Halmahera, Wetar, Damar, Babar, and into the Tanimbar Archipelago). The eastern distributional limit, sometimes given as the Aru Islands off the southwestern coast of New Guinea, is questionable.[4][5] They are also found in Sri Lanka (but not India[6]) and in southeastern China (Fujian, Hong Kong, and on Hainan Island).[2][7][3][4]
All members of the genus Cylindrophis share the following five characteristics: 1) a relatively blunt head, not distinct from the neck, with minute eyes and a mental groove; 2) the absence of well-developed ventral scales, with ventral scales only slightly larger than or equal in size to the dorsal scales; (3) the presence of a pair of pelvic spurs in both sexes; (4) a very short tail, often with conspicuous ventral coloration; and (5) contrasting light and dark ventral blotching.[4]
The body is cylindrical, with a near-uniform diameter, which leads to the name "pipe snakes". All species are small- to medium-sized, with total lengths ranging from 12.5 cm (5 inches) to 85.7 cm (34 inches).[4]
The teeth are moderate and subequal, with 10–12 in each maxilla and none in the premaxilla. There are no fangs and no evidence of venom. The eyes have round or vertically subelliptic pupils. The head has large symmetrical shields, with the nostrils in a single nasal, which forms a suture with its fellow behind the rostral. Loreal scale is present, a small postocular scale is present. The dorsal scales are smooth, in 17, 19, 21, or 23 rows depending on the species.[3][4][8]
When threatened, Cylindrophis flatten the posterior portion of their body and arch it above the ground to display their conspicuous ventral pattern, while the head remains concealed among the body coils.[4] Only one species, C. yamdena, lacks a bold ventral pattern in most individuals, having instead an orange-pink belly without bands or spots.[9]
Little is known of the foraging or mating behavior of Cylindrophis. At least one species uses constriction to subdue its prey,[10][11] which include elongate vertebrates: reptiles (snakes), amphibians (caecilians), and fish (eels).[10][12] Prey are swallowed from one end using rotational movements of the braincase and mandibles, a process that takes up to 30 minutes for larger prey.[13] This is distinct from the 'pterygoid walk' used by most other species of alethinophidian snakes, which have greater mobility of most skull bones than Cylindrophis.
The genus Cylindrophis contains the following 14 species.
Species[2] Taxon author[2] Common name[2] Geographic range[1][2][7][3][4] C. aruensis Boulenger, 1920 Aru cylinder snake Indonesia: The Aru Islands C. boulengeri Jean Roux, 1911 Boulenger's pipe snake Indonesia: the islands of Babar, Timor, and Wetar, and Timor-Leste C. burmanus Smith, 1943 Burmese pipe snake Myanmar C. engkariensis Stuebing, 1994 Malaysia: Borneo (Sarawak) C. isolepis Boulenger, 1896 Jampea Island pipe snake Indonesia: Jampea Island C. jodiae Amarasinghe, Ineich, Campbell & Hallermann, 2015 Jodi's pipe snake central Vietnam, Thailand C. lineatus Blanford, 1881 Blanford's pipe snake Indonesia: Borneo, and Malaysia: Sarawak C. maculatus (Linnaeus, 1758) Ceylonese cylinder snake Sri Lanka C. melanotus Wagler, 1828 black pipe snake Indonesia: Sulawesi (Celebes), the Tabukan Islands, the Sangihe Islands, the Sula Islands, Halmahera and Batjan C. opisthorhodus Boulenger, 1897 island pipe snake Indonesia: Lombok, Sumbawa, Komodo and Flores. C. osheai Kieckbusch, Mader, Kaiser, & Mecke, 2018 O’Shea's pipe snake, Boano pipe snake Indonesia: Boano C. ruffusT (Laurenti, 1768) red-tailed pipe snake Myanmar and southern China (Fujian, Hong Kong and on Hainan Island), south into Vietnam, Laos, Cambodia, Thailand, the Malay Peninsula and the East Indies to Indonesia (the Riau Archipelago, Sumatra, Bangka, Borneo, Java, Sulawesi, Buton and the Sula Islands) C. slowinskii Bernstein, Bauer, McGuire, Arida, Kaiser, Kieckbusch & Mecke, 2020[14] Slowinski's pipe snake Myanmar: Kachin state C. subocularis Kieckbusch, Mecke, Hartmann, Ehrmantraut, O’Shea & Kaiser, 2016 Indonesia: south-central Java C. yamdena Smith & Sidik, 1998 Yamdena pipe snake Indonesia: Yamdena IslandT: Type species.[1]
Many recent studies based on molecular data suggest that Cylindrophiidae may be paraphyletic with respect to another family of pipesnakes, Anomochilidae or dwarf pipesnakes.[15][16][17][18] Probably this will be resolved by including Anomochilidae within Cylindrophiidae in the future, but as of May 2018 no formal proposal to do so has been made.
In a broader sense, Cylindrophiidae & Anomochilidae are most closely related to Uropeltidae, a family of burrowing snakes from southern India & Sri Lanka. These three families are together called the Uropeltoidea and probably last shared a common ancestor in the Eocene, about 45 million years ago. Uropeltoids are probably most closely related to pythonoids,[18] and then to booids. These three groups probably last shared a common ancestor in the late Cretaceous, about 75 million years ago.[16]
The Cylindrophiidae are a monotypic family of secretive, semifossorial, non-venomous snakes containing the genus Cylindrophis found in southeastern Asia. These are burrowing snakes and most have a banded pattern on the belly. Currently, 13 species are recognized, all with no subspecies. Common names include Asian pipe snakes or Asian cylinder snakes.
