ARS | Publication request: THE POTENTIAL FOR AN EXOTIC HETEROPHID TREMATODE TO INVADE AND CAUSE DISEASE IN FOUR MAJOR AQUACULTURE SPECIES

Submitted to: International Aquatic Animal Health Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: August 30, 1998
Publication Date: N/A

Technical Abstract: A heterophyid trematode reported from wild fish in Texas and tropical fish in Florida and was examined to determined if it had potential to spread to cultured fish species in other states. Cercariae of this unnamed trematode established infection in channel catfish (Ictalurus punctatus), sunshine bass (Morone chrysops female X Morone saxatilis male), golden shiners (Notemigonus crysoleucas) and fathead minnows (Pimephales promelas). Penetration of the cercariae occurred in less than three minutes and the trematodes positioned themselves along the cartilage support of the gill filament. A strong host response, host cyst production, cartilage displacement and proliferation of epithelial tissue on the filament edges, was observed in sunshine bass and fathead minnows. Host responces in golden shiners and catfish, although similar, were slower and much less pronounced. Histological examination showed the parasites were encased in a cyst-like structure composed of cartilage and there was displacement and distortion of adjacent filament cartilage. There were no inflammatory cells present. The gill surface adjacent to the cysts exhibited moderate epithelial hyperplasia. The strong host response to this trematode indicates that it could cause serious disease problems in sunshine bass and fathead minnows and to a lesser extent in