চকৰিফেঁটী সাপ

অসমীয়া ৱিকিপিডিয়াৰ পৰা
Monocled cobra
চকৰিফেঁটী সাপ
সংৰক্ষণ স্থিতি
জীৱবৈজ্ঞানিক শ্ৰেণীবিভাজন
জগৎ/ৰাজ্য: Animalia
পৰ্ব: Chordata
শ্ৰেণী: Reptilia
বৰ্গ: Squamata
উপবৰ্গ: Serpentes
পৰিয়াল: Elapidae
গণ: Naja
প্ৰজাতি: N. kaouthia
বৈজ্ঞানিক নাম
Naja kaouthia
Lesson, 1831
Naja kaouthia distribution

চকৰিফেঁটী সাপ বা monocled cobra (Naja kaouthia) ফেঁটীসাপৰ এটা প্ৰজাতি। ইয়াক মধ্য এছিয়া আৰু দক্ষিণ এছিয়াৰ বহু অঞ্চলত পোৱা যায়।

শ্ৰেণীবিভাজনৰ ইতিহাস[সম্পাদনা কৰক]

১৮৩১ চনত René Lesson নামৰ ব্যক্তিজনে চকৰিফেঁটী সাপক ভাৰতীয় ফেঁটী সাপতকৈ পৃথক এক ধুনীয়া সাপ বুলি বৰ্ণনা কৰে যাৰ সন্মখৰ ফালে ১৮৮ টা স্কে'ল আৰু পিঠিৰ ফালে ৫৩ যোৰ স্কে'ল থাকে।[2]

তেতিয়াৰে পৰা কেইবাবিধো চকৰিফেঁটী সাপক ভিন ভিন বৈজ্ঞানিক নামেৰে বৰ্ণোৱা হৈছে:

  • ১৮৩৪ চনত জন এড্‌ৱাৰ্ড গ্ৰে'-এ থমাছ হাৰ্ড্‌ৱিকে অঁকা চকৰিফেঁটী সাপৰ ছবি Naja tripudians var. fasciata নামেৰে প্ৰকাশ কৰে।[3]
  • ১৮৩৯ চনত থমাছ কেণ্টৰে Naja larvata নামেৰে অগণন পাতল হালধীয়া পথালি আঁচ থকা আৰু ফণাত এটা বগা চকৰি থকা মাটীয়া ৰঙৰ চকৰিফেঁটী সাপৰ বৰ্ণনা দিয়ে। ইয়াক বম্বে, কলিকতা আৰু অসমত পোৱা গৈছিল।[4]

Naja tripudians নামেৰে চকৰিফেঁটী সাপৰ কেইবাবিধো প্ৰকাৰ ১৮৯৫ৰ পৰা ১৯১৩ চনৰ ভিতৰত উল্লেখ কৰা হৈছিল।

  • Naja tripudians var. scopinucha 1895
  • Naja tripudians var. unicolor 1876
  • Naja tripudians var. viridis 1913
  • Naja tripudians var. sagittifera 1913

১৯৪০ চনত মেল্‌কম আৰ্থাৰ স্মিথে চকৰিফেঁটী সাপক Naja naja kaouthia নাম দি spectacled cobra-ৰ অন্তৰ্গত কৰে।[5]

  • Naja kaouthia kaouthia – Deraniyagala, 1960

বিৱৰণ[সম্পাদনা কৰক]

এটা কমবয়সীয়া চকৰিফেঁটী সাপ

চকৰিফেঁটী সাপৰ ফণাত চকৰিৰ নিচিনাকৈ এট ঘূৰণীয়া (monocellate) বিন্যাস থাকে (ভাৰতীয় ফেঁটী সাপতকৈ বেলেগ)। কম বয়সীয়া সাপৰ ৰঙৰ ভিন্নতা কম। সাপডালৰ সন্মুখভাগ হালধীয়া, মুগা, ধোঁৱাবৰণীয়া বা ক'লা ৰঙৰ হয় আৰু পথালি আঁচৰ সমষ্টি থাকিব বা নাথাকিব পাৰে। ই জলফাই বৰণীয়া বা মাটীয়া বা ক'লা বৰণৰ হ'ব পাৰে আৰু ফণাত ফালধীয়া বা কমলা ৰঙৰ ঘূৰণীয়া দাগ থাকিব বা নাথাকিব পাৰে। It has a black spot on the lower surface of the hood on either side, and one or two black cross-bars on the belly behind it. The rest of the belly is usually of the same color as the back, but paler. As age advances, it becomes paler, when the adult is brownish or olivaceous. The elongated nuchal ribs enable a cobra to expand the anterior of the neck into a “hood”. A pair of fixed anterior fangs is present. The largest fang recorded measured ৬.৭৮ mm (০.৬৭৮ cm). Fangs are moderately adapted for spitting.[6] Adult monocled cobras reach a length of ১.৩৫ to ১.৫ m (৪.৪ to ৪.৯ ft) with a tail length of ২৩ cm (৯.১ in). Many larger specimens have been recorded, but they are rare. Adults can reach a maximum of ২.৩ m (৭.৫ ft) in length.[7][8]

Scalation[সম্পাদনা কৰক]

They have 25 to 31 scales on the neck, 19 to 21, usually 21, on the body, and 17 or 15 on the front of the vent. They have 164 to 197 ventral scales and 43 to 58 subcaudal scales.[7]

Monocled cobras tend to have more than one cuneate scale on each side. The shape of the frontal scale is short and square. Ventrals in males range from 170 to 192, in females from 178 to 197. Subcaudals in males range from 48 to 61, in females from 46 to 59.[6]

বিতৰণ আৰু বাসস্থান[সম্পাদনা কৰক]

চকৰিফেঁটী সাপ ভাৰতৰ পৰা চীন, ভিয়েটনাম আৰু কম্বোডিয়া পৰ্যন্ত পোৱা যায়। বাংলাদেশ, ভূটান, ম্যানমাৰ, লাওচ, নেপাল আৰু থাইলেণ্ডতো ইয়াক পোৱা যায়।

Monocled cobras can adapt to a range of habitats, from natural to anthropogenically impacted environments. They prefer habitats associated with water, such as paddy fields, swamps, and mangroves, but can also be found in grasslands, shrublands, and forests. It also occurs in agricultural land and human settlements, including cities. They can be found up to elevations of ১,০০০ m (৩,৩০০ ft) above sea level.[1]

আচৰণ[সম্পাদনা কৰক]

Monocled cobras are terrestrial and most active at dusk and in the evening. In rice-growing areas, they hide in rodent burrows in the dykes between fields and have become semi-aquatic in this type of habitat. Juveniles feed mostly on amphibians, and adults prey on small mammals, snakes and fish. When disturbed they take flight, but they have rarely been observed to spit venom.[6] However, when threatened, they will raise the anterior portions of their bodies, spread their hood, usually hiss loudly, and strike in an attempt to bite and defend themselves.[8]

They are often found in tree holes and areas where rodents are plentiful.[9]

প্ৰজনন[সম্পাদনা কৰক]

This is an oviparous species. Females lay between 16 and 33 eggs per clutch. Incubation periods range from 55 to 73 days.[10] Egg-laying takes place in January to March. The females usually stay with the eggs. Some collaboration between males and females has been reported in Naja naja x Naja kaouthia - hybrids.[6]

সংৰক্ষণ স্থিতি[সম্পাদনা কৰক]

This species has been assessed as Least Concern by IUCN owing to its large distribution, tolerance of a broad range of habitats, including anthropogenically altered environments, and its reported abundance. No major threats have been reported, and the species is not thought to be undergoing a significant population decline. In places the distribution of this species coincides with protected areas, probably providing small safeguards. Monocled cobras are harvested for the skin trade, however, collection from the wild is minimal and not likely to be causing significant population declines.[1] Naja kaouthia is listed on CITES Appendix II.[11]

বিষ[সম্পাদনা কৰক]

Monocled cobras at Snake Farm in Bangkok

The median lethal dose is 0.28-0.33 mg/gram of mouse body weight.[8] The major toxic components in cobra venoms are postsynaptic neurotoxins, which block the nerve transmission by binding specifically to the nicotinic acetylcholine receptor, leading to flaccid paralysis and even death by respiratory failure. The major α-neurotoxin in Naja kaouthia venom is a long neurotoxin, α-cobratoxin; the minor α-neurotoxin is different from cobrotoxin in one residue.[12] The neurotoxins of this particular species are weak.[13] The venom of this species also contains myotoxins and cardiotoxins.[14][15]

In case of intravenous injection the সাঁচ:LD50 tested in mice is 0.373 mg/kg, and 0.225 mg/kg in case of intraperitoneal injection.[16] The average venom yield per bite is approximately 263 mg (dry weight).[17]

The monocled cobra causes the highest fatality due to snake venom poisoning in Thailand.[18] Envenomation usually presents predominantly with extensive local necrosis and systemic manifestations to a lesser degree. Drowsiness, neurological and neuromuscular symptoms will usually manifest earliest; hypotension, flushing of the face, warm skin, and pain around bite site typically manifest within one to four hours following the bite; paralysis, ventilatory failure or death could ensue rapidly, possibly as early as 60 minutes in very severe cases of envenomation. However, the presence of fang marks does not always imply that envenomation actually occurred.[19]

In Myanmar (Burma), Maung TM, a 20-year old male was admitted to Insein hospital (near Yangon), within one hour of being bitten by a monocled cobra on the inner side of thigh. In fact he was bitten while squatting to urinate in the field. On admission there was a black patch and gross swelling at the site of the bite. Polyvalent serum, containing anti-viper and anti-cobra, was given intravenously on admission. On the next day the eye lids drooped and he developed signs of respiratory paralysis which demanded immediate tracheostomy and mechanical ventilation. He was again given antivenom with atropine and prostigmine with good response. The drugs were repeated as their actions had been only short lasting. The development of respiratory paralysis after an apparent recovery may indicate that there was a depot of venom at the site of bite from which it was absorbed slowly. This assumption may call for local infiltration. Locally there was extensive necrosis and ulceration requiring skin grafting at a later date.[20]

আৰু চাওক[সম্পাদনা কৰক]

তথ্যসূত্ৰ[সম্পাদনা কৰক]

  1. 1.0 1.1 1.2 Bain, R. H. (2009). "Naja kaouthia". IUCN Red List of Threatened Species. Version 2011.1. International Union for Conservation of Nature. http://www.iucnredlist.org/apps/redlist/details/177487. 
  2. Lesson, R.-P. (1831) Catalogue des Reptiles qui font partie d’une Collection zoologique recueillie dans l’Inde continental ou en Afrique, et apportée en France par M. Lamare-Piqout. Catalogue dressé (juillet 1831). 25. Le Naja Kaouthia, Naja kaouthia, Less.. Bulletin des Sciences Naturelles et de Géologie, Tome XXV: 122.
  3. Gray, J. E. (ed.) (1834) Cobra Capella. Illustrations of Indian zoology chiefly selected from the collection of Maj.-Gen. Hardwicke. Vol. II: Plate 78.
  4. Cantor, T. (1839) Naja larvata. Proceedings of the Zoological Society of London. Vol. VII: 32–33.
  5. Smith, M. A. (1940) Naja naja kaouthia. Records of the Indian Museum. Volume XLII: 485.
  6. 6.0 6.1 6.2 6.3 Wüster, W. (1998). The cobras of the genus Naja in India. Hamadryad, 23(1): 15−32.
  7. 7.0 7.1 Smith, M. A. (1943) Naja naja kaouthia In: The Fauna of British India, Ceylon and Burma, Including the Whole of the Indo-Chinese Sub-Region. Reptilia and Amphibia. Volume III (Serpentes). Taylor and Francis, London. Pages 428–432.
  8. 8.0 8.1 8.2 Chanhome, L., Cox, M. J., Vasaruchaponga, T., Chaiyabutra, N. Sitprija, V. (2011). Characterization of venomous snakes of Thailand. Asian Biomedicine 5 (3): 311–328.
  9. "Naja kaouthia: General Details and Information". WCH Clinical Toxinology Resource. University of Adelaide. http://www.toxinology.com/fusebox.cfm?fuseaction=main.snakes.display&id=SN0040। আহৰণ কৰা হৈছে: 3 February 2012. 
  10. Chanhome, L, Jintkune, P., Wilde, H., Cox, M. J. (2001). Venomous snake husbandry in Thailand. Wilderness and Environmental Medicine 12: 17–23.
  11. "Status of Naja kaouthia". CITES species database. CITES. http://www.unep-wcmc-apps.org/isdb/CITES/Taxonomy/tax-common-result.cfm/isdb/CITES/Taxonomy/tax-common-result.cfm?source=animals&displaylanguage=eng&Common=16665&Country=&tabname=status। আহৰণ কৰা হৈছে: 3 February 2012. 
  12. Wei, J.-F., Lü, Q.-M., Jin, Y., Li, D.-S., Xiong, Y.-L., Wang, W.-Y. (2003). α-Neurotoxins of Naja atra and Naja kaouthia Snakes in Different Regions. Acta Biochimica et Biophysica Sinica 35 (8): 683–688.
  13. Ogay, A.; Rzhevskya, D. I., Murasheva, A. N., Tsetlinb, V. I., Utkin, Y. N. (2005). "Weak neurotoxin from Naja kaouthia cobra venom affects haemodynamic regulation by acting on acetylcholine receptors". Toxicon খণ্ড 45 (1): 93–99. doi:10.1016/j.toxicon.2004.09.014. PMID 15581687. http://www.sciencedirect.com/science/article/pii/S0041010104004027। আহৰণ কৰা হৈছে: 25 December 2011. 
  14. Mahanta, M.; Mukherjee, A. K. (2001). "Neutralisation of lethality, myotoxicity and toxic enzymes of Naja kaouthia venom by Mimosa pudica root extracts". Journal of Ethnopharmacology খণ্ড 75 (1): 55–60. doi:10.1016/S03788741(00)003731. http://www.sciencedirect.com/science/article/pii/S0378874100003731। আহৰণ কৰা হৈছে: 25 December 2011. 
  15. Fletcher, J. E.; Jiang, M.-S.; Gong, Q.-H.; Yudkowsky, M. L.; Wieland, S. J. (1991). "Effects of a cardiotoxin from Naja naja kaouthia venom on skeletal muscle: Involvement of calcium-induced calcium release, sodium ion currents and phospholipases A2 and C". Toxicon খণ্ড 29 (12): 1489–1500. doi:10.1016/0041-0101(91)90005-C. PMID 1666202. http://www.sciencedirect.com/science/article/pii/004101019190005C। আহৰণ কৰা হৈছে: 25 December 2011. 
  16. Fry, Dr. Bryan Grieg. "LD50 Menu". Australian Venom Research Unit. University of Queensland. http://www.venomdoc.com/LD50/LD50men.html। আহৰণ কৰা হৈছে: 25 December 2011. 
  17. Engelmann, W.-E. (1981). Snakes: Biology, Behavior, and Relationship to Man. প্ৰকাশক Leipzig; English version NY, USA: Leipzig Publishing; English version published by Exeter Books (1982). পৃষ্ঠা. 51. ISBN 0-89673-110-3. 
  18. Pratanaphon, R.; Akesowan, S., Khow, O., Sriprapat, S., Ratanabanangkoon, K. (1997). "Production of highly potent horse antivenom against the Thai cobra (Naja kaouthia)". Vaccine খণ্ড 15 (14): 1523–1528. doi:10.1016/S0264-410X(97)00098-4. PMID 9330463. http://www.sciencedirect.com/science/article/pii/S0264410X97000984। আহৰণ কৰা হৈছে: 25 December 2011. 
  19. Davidson, T.. "Snakebite Protocols: Summary for Human Bite by Monocellate Cobra (Naja naja kaouthia)". http://drdavidson.ucsd.edu/Portals/0/snake/Naja.htm. 
  20. Gopalakrishnakone, Chou, P, LM (1990). Snakes of Medical Importance (Asia-Pacific Region). প্ৰকাশক Singapore: Venom and Toxin Research Group National University of Singapore and International Society on Toxinology (Asia-Pacific section). পৃষ্ঠা. 235. ISBN 9971-62-217-3. 

অতিৰিক্ত পঠন[সম্পাদনা কৰক]

  • Wüster, Wolfgang (1993) A century of confusion: Asiatic cobras revisited. Vivarium 4 (4): 14–18
  • Cox, Merel J. (1995) Naja kaouthia Herpetological Review 26 (3): 156–157
  • Kyi, S. W., Zug, G. R. (2003) Unusual foraging behaviour of Naja kaouthia at the Moyingye Wetlands Bird Sanctuary, Myanmar. Hamadryad 27 (2): 265–266
  • Wüster, W. Thorpe, R.S. (1991) Asiatic cobras: Systematics and snakebite. Experientia 47: 205–209
  • Wüster, W., Thorpe, R.S., Cox, M.J., Jintakune, P., Nabhitabhata, J. (1995) "Population systematics of the snake genus Naja (Reptilia: Serpentes: Elapidae) in Indochina: Multivariate morphometrics and comparative mitochondrial DNA sequencing (cytochrome oxidase I)". Journal of Evolutionary Biolology 8: 493–510
  • Wüster, W. (1996) Taxonomic changes and toxinology: Systematic revisions of the Asiatic cobras (Naja naja complex). Toxicon 34 (4): 399–406
  • Wüster, W. (1998) The cobras of the genus Naja in India Hamadryad 23 (1): 15–32

বাহ্যিক সংযোগ[সম্পাদনা কৰক]

সাঁচ:Naja species