ATRACTASPIS - MINI REVIEW 



97 



Fig. 13 Ridges on the teeth of Pachyrhachis problematicus (arrow). 



new distribution record for engaddensis (Al-Sadoon & Abdo, 199 1 ; 

 see also Al-Sadoon et al, 1991; Gasperetti, 19881; Joger, 1997; 

 Schatti & Gasperetti, 1994). 



It should be pointed out that the toxicity of the venom of certain 

 species, such as A. microlepidota, may vary according to distri- 

 bution, causing death in certain cases (see above) or containing less 

 potent toxins in others (above and Table 1). 



As with other venoms, snakes and some mammals are also 

 resistant to Atractaspis engaddensis venom, including the local 

 mongoose (Herpestes ichneumon, Bdolah et al, 1997). At least in 

 one instance, it was found that a mongoose (Paracynictis selousi) 

 fed on a specimen of A. bibroni (Greene, 1997). 



There is no antiserum available against any of the Atractaspis 

 species. 



mainly because of their influence on the cardiovascular system, 

 which may lead to death. Only a very small number of lethal cases 

 has been recorded until now, perhaps a total of five, three by A. 

 microlepidota (one adult man and two girls aged 4 and 6), one by A. 

 irregularis, an adult man, and one unknown (Corkill et al., 1959; 

 Warrell et al. , 1 976). Despite the fact that A. engaddensis has one of 

 the most potent venoms known, all patients bitten by this species 

 finally recovered, one probably due to 'the immediate and energetic 

 treatment he received' (Chajek et al, 1974). Most recently (July, 

 2002) a forty-six-year-old man was bitten on the inner aspect of the 

 right thumb while trying to catch an Atractaspis engaddensis near 

 his home in the Judean Desert, some 1 5 km north west of Jericho. He 

 was taken to the hospital where he arrived after about 40 minutes in 

 serious condition. Resuscitation failed and he was pronounced dead 

 after about 45 minutes (Nadir & Stalnikowicz, personal communi- 

 cation). This is the first death by an Atractaspis engaddensis bite in 

 Israel. Another recent case, from Saudi Arabia, involved a two-year- 

 old-girl who died within one hour after being bitten on the foot by 

 what was identified as A. microlepidota engaddensis. The region 

 where the bite occurred, at Diriyah near Riyadh, Saudi Arabia, is a 



EVOLUTION 



The discussion of snake origin and evolution has been recently 

 revived by a new and renewed examination and analysis of the 

 fossils discovered by Haas (1979; 1980a; 1980b) at an Upper 

 Cretaceous site north of Jerusalem. While the debate on the eco- 

 logical origin (marine or terrestrial) and the relationships of these 

 specimens (mosasauroid or macrostomatan) is still going on (Lee 

 & Caldwell, 1998; Greene & Cundall, 2000; Tchernov et al, 

 2000), Rieppel & Zaher (2001) have recently concluded that 

 'Pachyrhachis is neither a basal snake, nor a link between snakes 

 and mosasauroids, but shows macrostomatan affinities instead'. 

 Pachyrhachis possesses ridges or cutting edges on its teeth 

 (Rieppel & Kearney, 2001; Fig. 13) and the teeth of another fossil, 

 Haasiophis, have still to be further investigated in detail. Should 

 furrows or any other suggestive structures be found, they could be 

 taken as plausible signs for the existence of some kind of glands 

 that might have secreted active substances, even before the 

 appearance of caenophidian snakes. 



ATRACTASPIDIDAE 



VIPERIDAE 



SARAFOTOXINS HEMORRHAGES HEMORRHAGINS PHOSPHOLIPASE 



A 2 -CONTAINING TOXINS 

 (VIPEROTOXINS; PRESYNAPTIC 

 NEUROTOXINS) 



ELAPIDAE 



PRESYNAPTIC NEUROTOXINS 

 POSTSYNAPTIC NEUROTOXINS 

 CARDIOTOXINS; CYTOTOXINS 



ANCESTRAL 

 ENDOTHELIN 



ANCESTRAL 

 PROTEASE 



ANCESTRAL PHOSPHOLIPASE 



Fig. 14 Schematic representation of the possible origin of some major snake venom toxins from enzymatic precursors (partly after Strydom. 1979). 



