At first glance, the venoms of all snakes appear similar. They are slightly opalescent fluids of lemon-yellow color. However, in their chemical composition, the two types of venom (vasotoxic and neurotoxic) differ significantly. They are similar only in that both are complex mixtures of biologically active substances with protein characteristics. The venom of vipers and rattlesnakes is rich in hydrolytic enzymes, whereas the venom of cobras and sea snakes is rich in peptide neurotoxins.