Boulenger's keelback

Boulenger's keelback[2] (Fowlea asperrima), also known commonly as the Sri Lankan keelback,[1] is a species of water snake in the family Colubridae. The species is endemic to Sri Lanka.[5][6][7][4]

For another species called Boulenger's keelback, see Hebius boulengeri.

Boulenger's keelback
Fowlea asperrimus
Taken by: Gunnar Pettersson(Wildlife Artist) at Sinharaja, Sri Lanka on 2008-02-19.
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Colubridae
Genus: Fowlea
Species:
F. asperrima
Binomial name
Fowlea asperrima
(Boulenger, 1891)[2]
Synonyms[3][4]
  • Tropidonotus asperrimus
    Boulenger, 1891: 281
  • Natrix piscator asperrimus
    — M.A. Smith, 1943
  • Natrix asperrimus
    — Taylor, 1950: 567
  • Xenochrophis asperrimus
    — Das 1996: 59
  • Fowlea asperrimus
    — Purkayastha et al., 2019

Etymology

The common name "Boulenger's keelback" is in honour of Belgian-born British herpetologist George Albert Boulenger.[8]

Habitat
See also: Bundala National Park § Fauna

F. asperrima is found in Sri Lanka,[8][9][10] in both dry and wet climatic zones up to 1,000 m (3,300 ft) above mean sea level. It is abundant in waterways, such as flooded rice fields, ponds, lakes, marshes, rivers and streams.[2][6][11]

Characteristics

The body of F. asperrima is short and cylindrical, and has a clear neck and slightly pointed head. The eyes have rounded pupils, and the nostrils are narrow, directed slightly upwards. The tail is long. At hatching, it is 10 cm (3.9 in) long and grows to an adult length of 40–70 cm (16–28 in). The female is longer.[2][6][7]

Scalation
See also: Snake scales § Nomenclature of scales

F. asperrima has one pair of internasals; the posterior parts are narrow. One loreal, preocular, postocular and three temporals are found. Of the 9 supralabials, 4 and 6 connect with the eye. Ventrals number 131–146, and the undivided subcaudals are 73–93 in count. At midbody there are 19 rows of dorsal scales, which are strongly keeled and rough.[12][2][7][11][13]

Colour

The dorsal body colour of F. asperrima is olive brown. The anterior half of the body has 20–32 distinct large black spots or cross bars. The posterior body may lack them or may be in light-colored irregular shapes. The head is dark in color. Two black lines run diagonally from behind the eyes to the corners of the mouth. Ventrally, the body is white. F. asperrimus can be easily identified by dark spots or bars on the first half of the body and two dark lines behind the eyes.[2][6]

Behaviour

F. asperrima is oviparous, diurnal and nocturnal. In dry conditions during the summer, it undergoes aestivation. It is active in water bodies in search of its prey, which consist mainly of fishes and frogs. It is known to be very aggressive. When threatened, it attempts to bite, by flattening its head and neck as does the cobra. The bite may cause wounds. Also, it may release a noxious odor.[2][6]

Breeding

The gestation period of F. asperrima is 55–67 days. Females do not guard the clutches of eggs, but they stay close to the nest. They lay clutches of four to 30 eggs between September and October.[2][6][11]

Common names

References
  1. de Silva, A. & Wickramasinghe, L.J.M. (2021). "Fowlea asperrimus". The IUCN Red List of Threatened Species. IUCN. 2021: e.T197191A123311972. Retrieved 15 January 2021.
  2. Boulenger, G.A. (1891). "Description of new oriental reptiles and batrachians". Annals and Magazine of Natural History. Taylor and Francis, Ltd. London. 6: 279–283.
  3. Smith, M.A. (1943). "3. Serpentes". The Fauna of British India, Ceylon and Burma, Including the Whole of the Indo-Chinese Sub-Region. Reptilia and Amphibia. Taylor and Francis, Ltd. London. p. 583.
  4. Fowlea asperrima at the Reptarium.cz Reptile Database. Accessed 19 January 2016.
  5. Das, I. [in French] & De Silva, A. (2005). Photographic guide to snakes and other reptiles of Sri Lanka. New Holland Publishers. p. 144.
  6. Suranjan Karunarathna, D. M. S. & Thasun Amarasinghe, A. A. (2011). "A Preliminary Survey of the Reptile Fauna in Nilgala Forest and its Vicinity, Monaragala District, Sri Lanka". Taprobanica. 3 (2): 69–76. doi:10.47605/tapro.v3i2.49.
  7. Taylor, Edward H. (1950). "The snakes of Ceylon". University of Kansas Science Bulletin. 33 (14): 519–603. ISSN 0022-8850.
  8. Beolens, Bo; Watkins, Michael & Grayson, Michael (2011). The Eponym Dictionary of Reptiles. Johns Hopkins University Press. pp. 33–35. ISBN 978-1-4214-0135-5. LCCN 1421401355.
  9. De Silva, A. (1998). Snakes of Sri Lanka: a checklist and an annotated bibliography. Dept. Wildlife Conservation/GEF/UNDP/FAO, Colombo.
  10. Wall, Frank (1921). Ophidia Taprobanica or the Snakes of Ceylon. Colombo Mus. (H. R. Cottle, govt. printer), Colombo. p. 581.
  11. Boulenger, G.A. (1893). Catalogue of the snakes in the British Museum.(Natural history) Vol. I. Taylor and Francis, London. p. 448.
  12. Vogel, G. & David, Patrick (2006). "On the taxonomy of the Xenochrophis piscator complex (Serpentes, Natricidae)" (PDF). Herpetologica Bonnensis. II: 241–246.
  13. Janzen, P.; Klaas, P. & Ziesmann, S. (2007). "Sri Lankas Schlangenfauna". Draco. 7 (30): 56–64.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.