Dasia haliana

Haly's tree skink
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Sauria
Family: Scincidae
Genus: Dasia
Species: D. haliana
Binomial name
Dasia haliana
(Nevill, 1887)[1]

The Haly's tree skink (Dasia haliana) is a species of tree skink found in Sri Lanka. Earlier thought to be found also in the Western Ghats, taxonomic studies have shown this to be a Sri Lankan endemic, differentiated from the Indian Dasia subcaeruleum.[2] It is the only arboreal skink in Sri Lanka.

Description

This arboreal skink, about 8 cm long, in the genus Dasia is distinct from all other sister species in having a smaller number of scale rows at the mid-body (22-24) and an enlarged set of vertebral row scales.[3]

Like other reptiles their taxonomic identification is based on scalation. They have a pointed snout and the distance of the nostril to tip is longer than the diameter of the eye. The scales above the nostril are not in contact with each other and the fronto-nasal scale is equal in width and length. The prefrontals are large and are separated from another narrow frontal. The interparietal scale is variable in size and when large separates the parietals. There are a pair of nuchal (nape) scales, four scales above the eye with the second being largest and the first and second in contact with the frontal. There are 7 or 8 supraciliaries, with the first being longer than the others. There are two loreals which are longer than their height. The temporal scales are larger than the scales on the sides of the neck. The tympanum of the ear is sunken and is less than a fourth of the diameter of the eye.

The dorsal scales have 3 or 5 blunt keels, two vertebral rows of scales are wider than the rest. The tail tapers to a point and is as long as the head and body. The limbs are short, the toes are long with 17 or 18 lamellae (or plate like scales) beneath the fourth toe. The palms and soles have flat tubercles with larger ones on the heel, especially in the male.

The colouration is yellowish-olive above, with broad black bands which are as wide as the space between them. There are 5 or 6 of these bands on the neck and body with a black mark on the occiput extending forward as streaks on top of the head. There are two lateral stripes passing through the eye and nostril. The underside is yellow.[4]

Habitat and distribution

This is the only arboreal skink in Sri Lanka. Known much from the dry zone of the country, including Pallegama, Dambulla, Polonnaruwa, Bakamuna, Horana, Anuradhapura, Palatupana, Gampaha and Jaffna. It was also reported from southern India but the species that occurs there was found to be different and given the name of Dasia johnsinghi.

Ecology

Confined to the dry zone plains, where they are found on large trees, occupying tree holes as refuge.

Reproduction

Copulation is known in late January and 2 eggs are produced in early March.

References

  1. ↑ "On some recent taxonomic advancement and the resultant problems in the arboreal skink genus Dasia Gray, 1839 (Reptilia: Scincidae)". Zootaxa 3914 (4): 495–500. 2015. doi:10.11646/zootaxa.3914.4.9.
  2. ↑ Wickramasinghe, L.J.M., N. Wickramasinghe & L. Kariyawasam (2011). "Taxonomic status of the arboreal Skink Lizard Dasia halianus (Haly & Nevill, 1887) in Sri Lanka and the redescription of Dasia subcaeruleum (Boulenger, 1891) from India". Journal of Threatened Taxa 3 (8): 1961–1974. doi:10.11609/jott.o2300.1961-74.
  3. ↑ Inger, R F & W C Brown (1980). "Species of the scincid genus Dasia Gray". Fieldiana: Zoology 3: 1–11. doi:10.5962/bhl.title.3190.
  4. ↑ Smith, M. A. 1935. The Fauna of British India. Reptilia and Amphibia Vol II - Sauria. Taylor and Francis. London. pp. 278-279

Other sources

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