Invasion of Tilapia mossambica (cichlidae) viscera by the monogenean Enterogyrus cichlidarum.

The monopisthocotylean monogenean Enterogyrus cichlidarum, which normally inhabits the stomach and anterior intestinal lumina of tilapine cichlids, invaded the internal organs of juvenile Mozambique tilapia (Tilapia mossambica). Adult worms infected the intestinal mucosa, peritoneal cavity, liver, heart, blood vessels, swimbladder, and braincase. Most of the parasites were adults and contained eggs. Both adults and eggs incited a mononuclear inflammatory response. Infections were associated with chronic morbidity and mortality. Although affected fishes were overcrowded, the precise stress responsible for such an unusually invasive event is unknown.