Comparison of biological and biochemical characteristics of venom from rattlesnakes in the southern Baja California Peninsula.

In Mexico more than 40% of reported snakebites are due to rattlesnake species. In general, the venoms of these snakes are characterized by the presence of highly enzymatic components that could provoke coagulopathies, local and systemic tissue damage and some cases neurotoxicity. In northwestern Mexico (Baja California Peninsula, Gulf of California and Pacific islands), 15 species of Crotalus are distributed. Such a biodiversity implies a high variability in venom compositions that in turns would results in high variability in clinical manifestations. In this work, venoms of Crotalus catalinensis, C. enyo enyo, C. mitchellii mitchellii and C. ruber lucasensis were studied. Lethal doses from 0.35 to 9.21 mg/kg were obtained being venom of C. m. mitchellii the most potent of all. Venoms of C. catalinensis, C. e. enyo and C. r. lucasensis show high hemorrhagic potency (1.34, 1.48 and 1.68 μg respectively). Coagulant activity was found in venoms of C. catalinensis (4.6 μg), C. e. enyo (101.9 μg) and C. m. mitchellii (13.6 μg). Our results point out hemorrhage as one of the most expected signs by three of the four most abundant species in the area. Also, neurotoxicity must be expected by C. m. mitchellii.