Has potent hemolytic activity (PubMed:10964707). Is lethal to mice and crayfish (PubMed:10964707). Causes cutaneous inflammation in humans (PubMed:10964707). May act as a pore-forming toxin, disrupting normal transmembrane ion concentration gradients in susceptible cells (Probable). Oligomer. Forms a membrane channel in the prey. It is suggested that CrTX-B is synthesized in the tentacle, is modified (become CrTX-A) and then migrates to the nematocyst. Contains disulfide bonds. LD(50) is 20 ug/kg by intravenous injection into mice and 5 ug/kg by intraperitoneal injection into crayfish. CrTX-A and CrTX-B are encoded by the same gene. However, they differ by their molecular masses (43 and 46 kDa, respectively). In addition, CrTX-A is primarily localized in nematocysts, whereas CrTX-B is only detected in the tentacle without nematocyst. Belongs to the jellyfish toxin family. Type II subfamily.