BLOOD-FEEDING ARTHROPODS - LIVE SYRINGES OR INVERTEBRATE PHARMACOLOGISTS

The habit of blood feeding evolved independently several times among t he > 14,000 species and 400 genera of hematophagous arthropods. The sp ecific need to remove blood from the host's skin led to sophisticated mechanical adaptations in invertebrate mouthparts. Moreover, the need to counteract the vertebrate host's hemostasis Led to the evolution of salivary antihemostatic compounds injected into the host by these sam e mouthparts. The convergent evolution scenario for hematophagy has re sulted in a large diversity of salivary anticlotting, antiplatelet, an d vasodilatory substances. Thus, in addition to excelling as phlebotom ists, hematophagous arthropods excel as pharmacologists.