Fig. 2

Electron micrographs of parasitized intestine of Esox lucius. a Numerous mast cells (MCs) (arrows) are scattered inside the lamina propria-submucosa; arrow heads indicate granules released due to degranulation. b High magnification of two MCs. Eccentric polar nuclei (asterisks) and many electron-dense granules (arrow heads) inside their cytoplasm are visible. c A MC (thick arrow) occupied the whole lumen of a small capillary; two nuclei (arrows) of endothelial cells of capillary are evident. d Micrograph shows a neutrophil (arrow head) and several MCs (arrows) scattered among the collagenous fibres (asterisks). Scale-bars: a, 4 μm; b, 1.25 μm; c, 1.43 μm; d, 2.86 μm