Fig. 4
From: A severe microsporidian disease in cultured Atlantic Bluefin Tuna (Thunnus thynnus)
Transmission electron micrographs of Glugea thunni from the caecal mass of Thunnus thynnus from the Mediterranean Sea. a Longitudinal section of an adult microspore showing the ultrastructure (scale bar 500 nm). b Detail of the anchoring disk and spore wall (scale bar 400 nm). c Detail of polar filament surrounding the spore (scale bar 1 µm). Abbreviations: AD—anchoring disk; En—wall endospore; Ex—wall exospore; N—spore nucleus; PF—polar filament; Pp—polaroplast; PV—posterior vacuole; Wa—spore wall