A new study published in the Proceedings of the National Academy of Sciences shows that cone snails use a pretty neat tactic to capture prey. They release insulin to lower blood sugar (i.e. hypoglycemic shock), which immobilizes fish for an easy meal. The venomous insulin is molecularly different from molluscan insulin and was actually found to be similar to fish insulin.

Sources:

Safav-Hemami H, Gajewiak J, Karanth S, Robinson SD, Ueberheide B, Douglass AD, Schlegel A, Imperial JS, Watkins M, Bandyopadhyay PK, Yandell M, Li Q, Purcell AW, Norton RS, Ellgaard L, Olivera BM. Specialized insulin is used for chemical warfare by fish-hunting cone snails. Proceedings of the National Academy of Sciences. In Press. doi: 10.1073/pnas.1423857112