Ultrastructure of the Peritrich Ciliate Ambiphrya ameiuri and Its Attachment to the Gills of the Catfish Ictalurus punctatus1

Abstract

Ambiphrya ameiuri is an ectocommensal peritrich that attaches to the gills of warm‐water fishes and filters bacteria from the water. The ultrastructure of this protozoon, its attachment to the fish gills, and its effect on the gill tissue were investigated by scanning and transmission electron microscopy. The peritrich attached to the gills by fibers extending from the scopula. A microtubular array, apparently a barren kinetosome, was present in each lobular projection, but no scopular cilia were observed. At low densities Ambiphrya had no apparent harmful effects on the fish; however, at high densities respiration may be impeded. Ultrastructural studies indicate that this organism receives no nourishment from the host tissue.

Major Ectoparasitic Protozoa of Fish and Other Aquatic Animals: With Particular Emphasis on Morphology, Biology, Epidemiology, Pathology, Diagnosis, Prevention and Control

“…In small ponds (1 hectare) fish are not spared even in relatively mild winters, with minimum temperatures above Although there are a number of reports on poor condition and mortalities, particularly of fry, coinciding with massive infestation of trichodinids, Trichodinella epizootica in particular [38], and the sessilians Apiosoma, Ambyphrya and Scopulata [39][40][41][42][43], histopathological changes in events of massiveinfections by these ectoprotozoans are hardly evident, if occurring at all [44,45]. Trichodinella epizootica in carp [38] and Tripartiella cichlidarum in cichlids [43] cause some erosion of the gill epithelium.…”

“…However, food vacuoles of trichodinids revealed bacteria rather than sloughed cells [45]. Ultrastructural observation on attached Apiosoma did not reveal any interference with the host cell serving as substrate [38,44,46] or peripheral tissue response. Thus, mortalities following massive colonization of gills by sessilians [39] could result from the dense cover of sessilians disrupting gas exchange through the respiratory epithelium.…”

A Severe Outbreak of Ectoparasitism Due to Epistylis sp. in Pond‐Reared Orconectid Crayfish1

“…Peritrichous ciliated protozoans, such as Epistylis sp., are generally considered ectocommensals, attaching to the exoskeleton and gills of crustaceans, and feed primarily on bacterial cells (Johnson 1977;Fitzgerald et al 1982) associated with eutrophic ponds. Statistically significant correlations have been shown between turbidity and prevalence of Epistylis sp.…”