A spitting cobra is any of several species of cobras that can defensively spray a toxic secretion - functioning as both a venom (that can be injected via a wound) and a toxungen (that can be sprayed on the target surface) - from their fangs into the eyes of an attacker.
Schematic comparison between sections of non-spitting cobra fangs (left) and spitting (right). Spitting cobras on the right. 1: Section of the whole fang in the sagittal plane. 2: Horizontal section through the fang at the discharge orifice. 3: Frontal view of the discharge orifices.
The spat toxungen is generally harmless on intact mammalian skin (although contact can result in delayed blistering of the area), but can cause permanent blindness if introduced to the eye; if left untreated it may cause chemosis and corneal swelling.
The toxungen sprays out in distinctive geometric patterns when muscles squeeze the glands to squirt it out through forward-facing holes near the tips of the fangs.[1] Individuals of some species of spitting cobras make hissing exhalations/lunging movements of their heads when "spitting", and such actions may assist in propelling the venom, but research does not support the hypothesis that they play any major functional part except possibly enhancing the threatening effect of the behaviour.[2][3] When cornered, some species "spit" their toxungen as far as 2 m (6.6 ft).[4] While spitting typically is their primary form of defense, all spitting cobras also can deliver their toxin as a venom by biting.
Most spitting cobras' venom/toxungen is significantly cytotoxic, apart from the neurotoxic and cardiotoxic effects typical of other cobra species. The ability to spit likely evolved in cobras three times independently through convergent evolution.[4] In each of these three events the venom convergently evolved to be more effective at creating pain in mammals to serve as a better deterrent, with each of the three evolutions roughly correlating with the evolution and/or arrival of early hominins.[5]
Species
ǂ: Not a “true spitting cobra”, although these species have the ability to “eject” venom, they rarely do so and when they do use this defense, it is exceptionally rare.
Some of the Viperidae have been reported to spit occasionally.[6]
References
^Young, B. A.; Dunlap, K.; Koenig, K.; Singer, M. (September 2004). "The buccal buckle: The functional morphology of venom spitting in cobras". Journal of Experimental Biology. 207 (20): 3483–3494. doi:10.1242/jeb.01170. PMID 15339944.
^Berthé, Ruben Andres. Spitting behaviour and fang morphology of spitting cobras. Doctoral thesis, Rheinischen Friedrich-Wilhelms-Universität, Bonn, April 2011.
^Rasmussen, Sara; Young, B.; Krimm, Heather (September 1995). "On the 'spitting' behaviour in cobras (Serpentes: Elapidae)". Journal of Zoology. 237 (1): 27–35. doi:10.1111/j.1469-7998.1995.tb02743.x.
^ abPanagides, Nadya; Jackson, Timothy N. W.; Ikonomopoulou, Maria P.; Arbuckle, Kevin; Pretzler, Rudolf; Yang, Daryl C.; Ali, Syed A.; Koludarov, Ivan; Dobson, James; Sanker, Brittany; Asselin, Angelique (2017-03-13). "How the Cobra Got Its Flesh-Eating Venom: Cytotoxicity as a Defensive Innovation and Its Co-Evolution with Hooding, Aposematic Marking, and Spitting". Toxins. 9 (3): E103. doi:10.3390/toxins9030103. ISSN 2072-6651. PMC5371858. PMID 28335411.
^Kazandjian, T. D.; Petras, D.; Robinson, S. D.; van Thiel, J.; Greene, H. W.; Arbuckle, K.; Barlow, A.; Carter, D. A.; Wouters, R. M.; Whiteley, G.; Wagstaff, S. C.; Arias, A. S.; Albulescu, L.-O.; Plettenberg Laing, A.; Hall, C.; Heap, A.; Penrhyn-Lowe, S.; McCabe, C. V.; Ainsworth, S.; da Silva, R. R.; Dorrestein, P. C.; Richardson, M. K.; Gutiérrez, J. M.; Calvete, J. J.; Harrison, R. A.; Vetter, I.; Undheim, E. A. B.; Wüster, W.; Casewell, N. R. (2021). "Convergent evolution of pain-inducing defensive venom components in spitting cobras" (PDF). Science. 371 (6527): 386–390. doi:10.1126/science.abb9303. ISSN 0036-8075. PMC7610493. PMID 33479150.
^Wüster, Wolfgang; Thorpe, Roger S. (December 1992). "Dentitional phenomena in cobras revisited: Spitting and fang structure in the Asiatic species of Naja (Serpentes: Elapidae)" (PDF). Herpetologica. 48 (4): 424–434. JSTOR 3892862.
Greene, Harry W. (1997) Snakes: The Evolution of Mystery in Nature. University of California Press, Berkeley and Los Angeles, California.
External links
Wikimedia Commons has media related to Spitting cobras.
Video of an African red spitting cobra spraying its venom
Video of an African red spitting cobra feeding
'Spitting Cobras' Sharp-Shooting Secrets"
January 07, 2023
spitting, cobra, spitting, cobra, several, species, cobras, that, defensively, spray, toxic, secretion, functioning, both, venom, that, injected, wound, toxungen, that, sprayed, target, surface, from, their, fangs, into, eyes, attacker, schematic, comparison, . A spitting cobra is any of several species of cobras that can defensively spray a toxic secretion functioning as both a venom that can be injected via a wound and a toxungen that can be sprayed on the target surface from their fangs into the eyes of an attacker Schematic comparison between sections of non spitting cobra fangs left and spitting right Spitting cobras on the right 1 Section of the whole fang in the sagittal plane 2 Horizontal section through the fang at the discharge orifice 3 Frontal view of the discharge orifices Juvenile red spitting cobra Naja pallida Red spitting cobra Handling of Naja siamensis using full face protection Contents 1 Venom 2 Species 3 References 4 External linksVenom EditThe spat toxungen is generally harmless on intact mammalian skin although contact can result in delayed blistering of the area but can cause permanent blindness if introduced to the eye if left untreated it may cause chemosis and corneal swelling The toxungen sprays out in distinctive geometric patterns when muscles squeeze the glands to squirt it out through forward facing holes near the tips of the fangs 1 Individuals of some species of spitting cobras make hissing exhalations lunging movements of their heads when spitting and such actions may assist in propelling the venom but research does not support the hypothesis that they play any major functional part except possibly enhancing the threatening effect of the behaviour 2 3 When cornered some species spit their toxungen as far as 2 m 6 6 ft 4 While spitting typically is their primary form of defense all spitting cobras also can deliver their toxin as a venom by biting Most spitting cobras venom toxungen is significantly cytotoxic apart from the neurotoxic and cardiotoxic effects typical of other cobra species The ability to spit likely evolved in cobras three times independently through convergent evolution 4 In each of these three events the venom convergently evolved to be more effective at creating pain in mammals to serve as a better deterrent with each of the three evolutions roughly correlating with the evolution and or arrival of early hominins 5 Species Editǂ Not a true spitting cobra although these species have the ability to eject venom they rarely do so and when they do use this defense it is exceptionally rare African cobras Naja ashei Naja katiensis Naja mossambica Naja nigricincta Naja nigricincta woodi Naja nigricollis Naja nubiae Naja pallidaAsian cobras Naja atra ǂ Naja kaouthia ǂ Naja sagittifera ǂ Naja mandalayensis Naja philippinensis Naja samarensis Naja siamensis Naja sputatrix Naja sumatranaSpitting snakes in other families Hemachatus haemachatusSome of the Viperidae have been reported to spit occasionally 6 References Edit Young B A Dunlap K Koenig K Singer M September 2004 The buccal buckle The functional morphology of venom spitting in cobras Journal of Experimental Biology 207 20 3483 3494 doi 10 1242 jeb 01170 PMID 15339944 Berthe Ruben Andres Spitting behaviour and fang morphology of spitting cobras Doctoral thesis Rheinischen Friedrich Wilhelms Universitat Bonn April 2011 Rasmussen Sara Young B Krimm Heather September 1995 On the spitting behaviour in cobras Serpentes Elapidae Journal of Zoology 237 1 27 35 doi 10 1111 j 1469 7998 1995 tb02743 x a b Panagides Nadya Jackson Timothy N W Ikonomopoulou Maria P Arbuckle Kevin Pretzler Rudolf Yang Daryl C Ali Syed A Koludarov Ivan Dobson James Sanker Brittany Asselin Angelique 2017 03 13 How the Cobra Got Its Flesh Eating Venom Cytotoxicity as a Defensive Innovation and Its Co Evolution with Hooding Aposematic Marking and Spitting Toxins 9 3 E103 doi 10 3390 toxins9030103 ISSN 2072 6651 PMC 5371858 PMID 28335411 Kazandjian T D Petras D Robinson S D van Thiel J Greene H W Arbuckle K Barlow A Carter D A Wouters R M Whiteley G Wagstaff S C Arias A S Albulescu L O Plettenberg Laing A Hall C Heap A Penrhyn Lowe S McCabe C V Ainsworth S da Silva R R Dorrestein P C Richardson M K Gutierrez J M Calvete J J Harrison R A Vetter I Undheim E A B Wuster W Casewell N R 2021 Convergent evolution of pain inducing defensive venom components in spitting cobras PDF Science 371 6527 386 390 doi 10 1126 science abb9303 ISSN 0036 8075 PMC 7610493 PMID 33479150 Wuster Wolfgang Thorpe Roger S December 1992 Dentitional phenomena in cobras revisited Spitting and fang structure in the Asiatic species of Naja Serpentes Elapidae PDF Herpetologica 48 4 424 434 JSTOR 3892862 Greene Harry W 1997 Snakes The Evolution of Mystery in Nature University of California Press Berkeley and Los Angeles California External links Edit Wikimedia Commons has media related to Spitting cobras Video of an African red spitting cobra spraying its venom Video of an African red spitting cobra feeding Discovery News Spitting Cobras Sharp Shooting Secrets Retrieved from https en wikipedia org w index php title Spitting cobra amp oldid 1126032562, wikipedia, wiki, book, books, library,
