Study of Some Snakes from Thanlyin Environs, Yangon Region Abstract Introduction Snakes Belong to the Order Squamata of the Subo
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East Yangon University Research Journal 2019 (Special Issue) 35 Study of some snakes from Thanlyin Environs, Yangon Region Aye Aye Than1, Nyo Mie Kyaing2, Nwe Nwe Aung3, Tin Nyunt4 Abstract A total of 11 snake species belonging to six families of order Squamata were recorded in Thanlyin environs. The aim of this study was to record the snake species distributed in this area. This study was conducted during May, 2001 to April, 2005. Collected species were identified and classified systematically. Descriptive account of each species was given by coloured photographs. Venomous, mildly venomous and non-venomous snakes were also distinguished. Out of the recorded snakes, six species were non-venomous, one species was mildly venomous and four species were venomous. Systematic positions, distinctive characters and distributions of the studied species were also described. Snake bite cases in the study area during the study period were also mentioned by figures. Key Words : Distinctive characters, venomous, mildly venomous and non-venomous snakes Introduction Snakes belong to the order Squamata of the suborder Serpentes. According to the recent Reptile Data Base, a total of 3709 snake species worldwide (Uetz et al., 2018). Snakes are limbless reptiles having an elongated body covered with scales which are arranged in rows. The form, structure and arrangement of the body scales are important for snake species identification (Sharma et al., 2013). This successful animal group inhabits virtually all terrestrial, fresh and sea water habitats in tropical, subtropical, temperate zones (Ernst and Zug, 1996). Snakes are the most feared and least understood of all animals. Snakes are cold blooded animals their body temperature being dependent on that of their surroundings (Ditmars,1962). Myanmar is one of the countries for richness of snake fauna in South East Asia. John Nichol, 1989 reported that more than 120 species of snakes existed in Myanmar. According to the report of Myanmar Herpetological Survey Project conducted with Forest Department and California Academy of Sciences (2010), a total of 172 species of serpents exist in Myanmar. 1,3. Lecturer, Dr, Department of Zoology, East Yangon University 2. Associate Professor, Dr, Department of Zoology, East Yangon University 4. Lecturer(Ret) Department of Zoology, East Yangon University 36 East Yangon University Research Journal 2019 (Special Issue) The venomous snakes in Myanmar are Russell’s viper, cobra, king cobra, krait, sea snakes and green snakes. For farmers, snakes are very useful because they help to control rodent populations by feeding on rats and mice that would otherwise damage crop or stored food (Sharma et al., 2013). These venomous snake bites affect the economically important farmers who are mostly bitten during their farming activities or on the way to the farm from their home. Thus, snake bite is particularly a great problem in Myanmar. Having one of the highest burdens of snake bites across the globe, it’s estimated more than 500 people die each year in Myanmar from snake bites, many as a result of acute kidney failure arising from the venom. Thanlyin Township and its environs were chosen as a study site. These environs possess many trees, ponds, lakes, marshes, shrubs, open field and green lands. The result of this study will be provided to understand the morphology and character of some venomous and non-venomous snakes in Thanlyin Environs. - to study the morphological characters of some collected snakes in the Thanlyin environs - to record the distribution of snake species in the study area - to assess the some snake bites case occurring during the study period Materials and Methods Study Area Thanlyin, Kyauktan, Khayan, Thongwa Townships were chosen as the study sites (Fig.1) Thanlyin Township 6 44 6 5 Kyauktan Township 6 38 6 Khayan Township 6 46 6 32 Thongwa Township 6 4 6 32 Study period Study period was lasted from May, 2001 to April, 2005. Collection of specimen The snakes were captured by using a snake hook and a snake tong from the study area by the help of villager and security staffs of East Yangon University. The natural colors of specimens were recorded. The measurement of scales count, and scale position of the head and tail were also recorded. Then they were preserved in 10% formalin for further study. East Yangon University Research Journal 2019 (Special Issue) 37 Identifications The identification of the specimens were followed after Boulenger (1890). Smith (1943), Cox et al. (1998), and Leviton et al. (2003) (Source: Google Map) Fig.1 Map of study area Results and Discussion A total of 11 snake species which belong to six families of order Squamata were recorded in Thanlyin environs. Districtive characters of collected snake species Boiga multomaculata (Boie, 1827) Common name - Large spotted cat snake Local name - Ngan-mwe-pwe-tu Body very slender, laterally compressed, head is large with two broad dark brown stripes which diverge posteriorly, distinct from neck, eyes are large with the elliptical pupil, Two series of asymmetrically arranged, large, more or less oval shaped, solid blackish or dark brown spots found in whole dorsal body. Mildly venomous snake Collecting date - 15.10.2003 Collecting site - Nyaung- wyne village Thanlyin Township . 38 East Yangon University Research Journal 2019 (Special Issue) Coelognathus radiatus (F.Boie,1827) Common name - Copper head snake Local name - Ngan zoung Posterior maxillary teeth largest; snout twice as long as the eye; loreal a little longer then high. Above grayish brown; with 4 black stripes on the anterior half of the body. Head with black collar, 3 black lines radiate from behind each eye. Body scales in 19 rows, more or less distinctly keeled. Non-venomous snake Collecting date - 10.6.2003 Collecting site- Nga-pyay-ma village Thanlyin Township Lycodon aulicus (Linnaeus,1758) Common name - Wolf snake Local name - House snake Body slender; head flattened; snout projecting beyond lower jaw; single precocular; postoculars 2; supralabials 9; 2 enlarged posterior maxillary teeth; eye small; pupil verticals; tail long; dorsals smooth. Dorsum brown or grayish-browth with 12-19 white cross-bars, sometimes speckled with brown, expanding laterally to enclose triangular patches; venter cream or yellow-white. Non-venomous snake Collecting date - 2.5.2002 Collecting site - Kha-yan Township Oligodon cyclurus (Cantor, 1839) Common name - Cantor’s kukri snake Local name - Myat shaw Body robust; subcylindrical; head short, indistinct from neck; loreal absent; single preocular; postocular 2; supralabials 6; infralabials 7; eye small; pupil rounded; dorsal smooth; anal divided. Dorsum purplish-brown with longitudinal dark brown stripes. Non- venomous snake Collecting date - 30.5.2002 Collecting site - East Yangon University Campus Ptyas mucosa (Linnaeus,1758) Common name - Rat snake Local name - Linn mwe East Yangon University Research Journal 2019 (Special Issue) 39 Body slender; head elongated, distinct from neck, pupil rounded, tail long; dorsal smooth or weakly keeled; anal divided. Dorsum yellowish or reddish brown to black; posterior of body with dark bands. Non- venomous snake Collecting date - 7.2.2003 Collecting site - Thone- gwa Township Xenochrophis piscator (Schneider,1799) Common name - Checkered keelback (or)water snake Local name - Yay mwe pyauk ma Body robust, cylindrical; head distinct from neck; single preocular; postocular 3; supralabials 9; nostrils directed slightly upwards; eye large; pupil round; dorsal scales strongly keeled. Dorsum olive-brown, black spots arranged in 5-6 rows.Non- venomous snake Collecting date - 3.8.2001 Collecting site - Mya-kaing village Kyauktan Township Xenopeltis unicolor Reinwordt,1827 Common name - Sunbean snake Local name - Mwe pya da Head much depressed, snout rounded, with anterior depression, rostral broader than high, internasals much smaller than prefrontals, frontal large; one supraocular present and small. Body scales in 15 rows. Non- venomous snake Collecting date - 10.12.2004 Collecting site - Kayin - seik village, Thanlyin Township Bungarus fasciatus (Schneider,1801) Common name - Banded kraits Local name - Ngan taw kyar One preocular, one supraocular, two postoculars, seven supralabials present; third and fourth supralabials touching the eye. Body scales in 15 rows. The banded krait is easily identified by its alternate black and yellow cross bands, its triangular body cross section, and the marked vertebral ridge. Venomous snake Collecting date - 15.10.2003 Collecting site - Kyauktan Township Naja kaouthia Lesson, 1831 Common name - Monocled cobra Local name - Mwe hout 40 East Yangon University Research Journal 2019 (Special Issue) Snout length twice of eye length. O-shaped or spectacle mark upon the hood. Body scales in 17 rows, smooth, more or less strongly keeled. Yellowish or brownish to black above. Venomous snake Collecting date - 15.11.2002 Collecting site - Mya Kaing village, Kyauktan Township Daboia russelii (Shaw & Nodder, 1797) Common name - Russell’s viper Local name - Mwe pwae Body robust; head distinct from neck; forehead with small scales; nostril enlarged, in large nasal shield; supralabials 10-12; eye small; pupil vertical; tail short. Dorsum light brown with 5-7 rows of large, black-margined orange-brown blotches along body. Venomous snake Collecting date - 20.4.2002 Collecting site -Khayan Township Enhydrina schistosa (Daudin,1803) Common name - Beaked sea snake Local name - Gyad pya Head shield entire, nostrils superior, nasals in contact