English: Histopathology of Hematodinium infections in Carcinus maenas (shore crab).
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.