Predatory behaviour of gekkonid lizards, Ptyodactylus spp., towards the scorpion Leiurus quinquestriatus hebraeus, and their tolerance of its venom

In the present pilot study the effect of the venom of the Israeli yellow scorpion (Leiurus quinquestriatus hebraeus (Birula, 1908)) on two Israeli fan-toed gecko lizards (Ptyodactylus guttatus von Heyden, 1827 and P. puiseuxi Boutan, 1893) was examined through (1) observations on feeding behaviour and (2) toxicity assays. It was shown that (1) the geckos ate the extremely venomous yellow scorpions in a sting-avoiding fashion and when occasionally stung they were not affected; (2) subcutaneous injections of lyophilized venom were survived by the scorpion-sympatric P. guttatus in doses of 1 mg of crude lyophilized venom per g of body weight (4000 times its LD₅₀ value for mice), in contrast with the presumably allopatric P. puiseuxi which died within 80 and 210 min from doses of 1 and 0.5 mg per g, respectively. The pharmacological and ecochemical aspects of the above tolerance are discussed.