Some Chemical and Zootoxicological Properties of Stingray Venom

A definitive chemical and pharmacological study has been carried out on the venom of the stingrays, particularly the round stingray Urobatis halleri, common to the Southern California coast. The lethal fraction of the venom is a protein of medium molecular weight, but apparently bound with an enzyme, or some other substance, which makes its separation as a pure substance very difficult. Pharmacological studies indicate that in severe envenomation, secondary shock can occur and can lead to death. A series of studies on the in vitro neutralization of Urobatis halleri venom with antivenins prepared against the bat stingray Myliobatis californicus and the round stingray U. castexi were carried out. One ml of the M. californicus antivenin neutralizes the lethal activity of 10 mg of bat stingray venom. On ml of the U. castexi antivenin neutralizes the lethal activity of 5 mg of this stingrays venom. The M. californicus antivenin provided little protection against the lethal activity of U. halleri venom. The U. castexi gave some protection at the 0.20 level, the 0. 50 level and the 1.00 level. It is apparent that there is some significant cross protection between the antivenins of these two stingray species. Further immunochemical work is in progress on the venoms of four Urobatis species.