Plate 3. Bacterial infections: a,b. Dropsy in carp from Kajansi farm, Uganda (× 0.8). c. Exophthalmus and cornea hyperplasia in eyes of Oreochromis sp. from Kajansi farm, Uganda (× 2.5). d. Ulcerating skin lesions in Synodontis afrofisheri from north Lake Victoria (× 0.8). e. Vibrio parahemoliticus (arrow) in kidney blood of farmed tilapia hybrid in Israel. f. V. parahemoliticus (arrow) in macrophage aggregate in spleen of a fish of the same group as e. g. Inflammatory lesions in winter stored tilapia hybrid with Pseudomonas sp. as presumptive causative agent. h–g. Histopathological process in tilapia hybrid spleen (h,j) and liver (i) due to pasteurellosis, from granulomatous lesion to liquifactious necrosis.

Plate 4. Bacterial infections continued: a-g. Pasteurellosis in cichlid fishes: a. Hepatocyte degeneration in tilapia-hybrid liver. b. degeneration and death of cells invaded by the bacteria; c,d. the resulting disintegration of the tissue due to infection (same fish). e–g. Pasteurellosis in angel fish (Pterophyllum scalare), showing nodular, bacteria loaded (arrows) lesions (abcesses) with gradually disintegrating macrophage-like cells. h,i. Epitheloid granulomatous lesions with acid fast positive bacteria (Mycobacteria) (arrows) in estuarine grey mullets from Israel (E, epitheloid cells; F, loose outer and, Fi, dense inner layers of fibroblasts; L, surrounding spleen tissue).

Plate 5. Epitheliocystis: a,b. Hypertrophic epitheliocystis infected cells on gills of Oreochromis aureus, Israel. c. Low mag. transmission electron microscopic (TEM) view of hypertrophic epitheliocystis infected cells (approx. 27 μm in diam) in gills of carp, Israel. d. Hyperinfected gill of Mugil cephalus, Israel. e–h. TEM view of epitheliocystis organisms: e. dividing round bodies (0.7 μm in diam.) and f,h. rods or elongate bodies (1–2 μm long) (same arrows), and cocci (elementary bodies) (0.5 × 0.3 μm) (open arrows) of Oreochromis Epitheliocystis; g, round bodies of carp epitheliocystis (0.4–0.8μm in diam) (W- host cell wall).