- (mesotocin, isotocin, valitocin, glumitocin, aspargtocin, vasotocin,
seritocin, asvatocin, phasvatocin), in
worms (annetocin, nematocin),
octopuses (cephalotocin...
- amphibians, lungfishes,
coelacanths Cys-Tyr-Ile-Gln-Ser-Cys-Pro-Ile-Gly-NH2
Seritocin Frogs Cys-Tyr-Ile-Ser-Asn-Cys-Pro-Ile-Gly-NH2
Isotocin Bony fishes...