A Study of Nematocyst Discharge of <i>Physalia physalis</i> and Venom Composition

Abstract

In this work, we studied the effects of various chemicals on P. physalis nematocyst discharge and the composition of the released venom. The exposure of nematocyst to K+ and Na+ induced a massive discharge in a short time of exposure. Conversely, the Ca2+ ions apparently resulted in an inhibitory effect. The electric stimulation was shown to be a reproducible and effective way to induce nematocyst discharge in a few seconds. The SDS-PAGE profile of the venom proteins released revealed a similar pattern, having a broad MW distribution and wide bands with 40, 25 and 20 kDa. The released venom exhibited proteolytic activities that are inhibited by PMSF and EDTA. The present study provides an overview of discharge sensation and venom released of P. physalis nematocysts and could contribute for future venom proteomics research efforts.

Keywords

• <i>Physalia physalis</i>
• venom toxins
• nematocyst discharge
• chemosensation