The Effects of Venom from a Fish-Hunting Cone Snail (Conus catus) on the Physiology of Danio rerio (Zebrafish) Embryos

Abstract

Fish hunting cone snails of the genus Conus are predatory gastropods whose venom contains post translationally modified peptides that targeted towards voltage gate channels and ligand gated ion channels. Conus catus use their venom to capture their prey affecting their entire nervous system. Though it only takes a single peptide to cause the prey to undergo tetanic paralysis, the exact target has yet to be discovered. This summer I have microinjected the toxin milked from Conus catus into Danio rerio (zebrafish) and observed its physiological effects on the organism. Toxin injections were preformed on embryos of different developmental stages starting at the 18 somite stage after they have been dechorionated (approximately after 18 hours after the egg has been laid). Carefully monitoring the amount and location of the venom injected in the time-staged organisms, their responses were recorded and documented. This was done to identify the exact time frame at which they first respond to the toxin enabling us to have a better understanding of the activity of the neuroexcitatory peptides. We have recently discovered that the venom not only affects the entire nervous system of the fish but also causes it to experience peristalsis in its anterior gut. Further experiments to find the exact target of the venom peptides will be preformed using focal electrodes and microelectrodes will be utilized to investigate the electrical activity.