Targets vasopressin-oxytocin related receptors (PubMed:32155768). Is more active on fish receptors than on their human counterparts, supporting an evolved role of this conopressin in the envenomation process (PubMed:32155768). Acts as an agonist on zebrafish vasopressin receptors V1a1R (EC(50)=10.6 nM), V1a2R (EC(50)=44.06 nM, partial agonist), V2R (EC(50)=299.2 nM) and oxytocin receptor (EC(50)=353.73 nM, partial agonist) (PubMed:32155768). Shows a weaker activity on human receptors AVPR1B (EC(50)=51.92 nM), AVPR1A (EC(50)=123.78 nM), AVPR2 (EC(50)=299.2 nM) and oxytocin (OXTR) receptor (EC(50)=455.66 nM, partial agonist). In vivo, exhibits grooming and scratching behavior in mice, following intracerebral injection (PubMed:3680228). Expressed by the venom gland. The cysteine framework of the conopressin is C-C. Belongs to the vasopressin/oxytocin family.