The host is the pelagic ctenophore "Mnemiopsis leidyi". Found at a depth of , it is the deepest dwelling ctenophore discovered. Among other projects that year, Morgan completed an experimental study of ctenophore embryology. The structure of these specialized cells is extremely complex and varies among ctenophore species. Once the tentacles are set, the ctenophore drifts passively. Egg production increases with ctenophore size, and it is unclear when senescence occurs. Ctenophore nerve cells and nervous system have different biochemistry as compared to other animals. In one experiment the ctenophore favored adult "Pseudocalanus minutus" more than other forms of zooplankton. In 1997 another ctenophore species arrived--"Beroe ovata", a predator of "Mnemiopsis leidyi".