FMRFamide, a neuropeptide involved in cardiac activity regulation, is found in Biomphalaria glabrata, a species of a freshwater snail best known for its role as the intermediate host for the human-infecting trematode parasite Schistosoma mansoni.
This freshwater snail species is used as a model organism, in other words, a non-human species which is extensively studied to understand a biological phenomenon, with the expectation that discoveries made in the model will provide insight into the workings of other organisms. Model organisms are in vivo models and are widely used to research human disease when human experimentation would be unfeasible or unethical.