Ichthyobodo - FHP

Science Center Objects

Fish Diseases


Gills from Lost Rver suckers with a heavy infestation of Ichthyobodo sp. (arrows)

Gills from Lost River suckers with a heavy infestation of Ichthyobodo sp. (arrows).  Slide is stained with hematoxylin and eosin. Credit: Carla Conway, USGS. (Public domain.)

Ichthyobodosis is a disease of freshwater and marine fishes caused by the flagellate parasite Ichthyobodo necator (previously named Costia necatrix). The parasite is found globally and infects a broad range of fish host species. Recent phylogenetic studies indicate that Ichthyobodo is a multi-species complex (Ichthyobodo spp.). The parasite attaches to the gills and skin of the fish. Fish with heavy infestations may appear lethargic, flash or rub against objects and suffer mortality if the condition is untreated. Research at the Western Fisheries Research Center has implicated Ichthyobodo sp. as a mortality factor of Lost River suckers (Deltistes luxatus) during mesocosm studies conducted in Upper Klamath Lake. Lost River suckers are endangered and high juvenile mortality is hindering recovery efforts. Current research focuses on better understanding the role of Ichthyobodo sp. in juvenile sucker mortality by use of histopathology and investigating epidemiological patterns of infection by use of molecular methods such as eDNA profiling.