Fig. 6

Histopathology of Hematodinium infections in C. maenas. a Multinucleate elongate form of the parasite (arrow) seen attached to the wall of haemolymph channel in gill lamella in a low severity (grade L1) infection. b Low power micrograph of gill lamellae from a crab with high severity (grade L4) infection showing large numbers of parasites (arrows). c Low power micrograph of the hepatopancreas from a crab with high severity infection. The intertubular space (*) is replete with different forms of Hematodinium. d, e High power micrographs showing the diversity of forms of the parasite including rounded (small arrows), multinucleate rounded and elongate forms (large arrows). Abbreviation: T, tubules. Scale-bars: a, 25 µm; b, c, 100 µm; d, e, 10 µm