- Structural and functional evolution of the vasopressin/oxytocin superfamily: vasopressin-related conopressin is the only member present in Lymnaea, and is involved in the control of sexual behavior. Van Kesteren, R.E., Smit, A.B., De Lange, R.P., Kits, K.S., Van Golen, F.A., Van Der Schors, R.C., De With, N.D., Burke, J.F., Geraerts, W.P. J. Neurosci. (1995)