Sporozoon tincae infection in tench. An ultrastructural investigation

Abstract

For several years now, pathological skin changes have been observed in tench Tinca tinca L. from northern Germany. Using light microscopy, numerous instances of the causative agent have been detected, cell-bound in macrophages and/or between altered tissue structures. The infection shows systemic spread, as the microorganisms, Sporozoon tincae, also appear in the spleen. Using electron microscopy, it was possible to depict numerous different features of the microorganism associated with the intracellular development and multiplication of the agent. The structures lacked a true cell nucleus, so the previous assignment of the organism to the Protozoa is no longer maintainable. Our findings demonstrate that S. tincae is not a eukaryotic organism. We suggest that S. tincae be classified as bacteria.

A review of the diseases and contaminant related mortalities of tench (Tinca tinca L.)

“…Fish showed changes of ulcerous character on fin bases, on the body wall and on the tail. Based upon electronmicroscopic studies, Kaup and Korting in 1994 classified S. tincae as a bacterium. Whilst this bacterium is localized in histiocytes of the subcutis, it can also be found in the spleen and liver of affected fish.…”