Histopathological and Hematological Changes in Mummichogs, Fundulus heteroclitus, Infected by a Pseudomonad

Abstract

The hematological and histopathological changes in mummichogs infected by Pseudomonas reptilivora included a dramatic reduction in hematocrit values; massive structural lymphoid necrosis with formation of edematous spaces in the splenic tissue; empty and degenerate hepatic veins and sinusoids; and necrosis of the renal tubules in naturally and experimentally infected fish. Electron microscopy of the renal tissue revealed clumps of chromatin in the nuclei, disintegration or degeneration of organelles, and an increase of digestive vesicles or autophagic vacuoles in the cells. This is the first description of the pathology of this bacteria in a marine fish. Key words: fish disease, Pseudomonas, bacteria, hemorrhagic septicemia