Figure 2

Fluorescently labelled parasite spores attach to the oesophagus of susceptible, but not resistant, Daphnia clones. (a) Picture of a susceptible Daphnia magna exposed to fluorescently labelled spores. The entire animal is shown. Parasites are attached on the epithelium of the oesophagus (arrow). Other labelled spores can be seen with the rest of the food in the end gut (arrowhead). (b) Picture of a resistant D. magna exposed to fluorescently labelled spores. The entire animal is shown. The oesophagus is free of parasite (arrow). Labelled spores can be seen with the rest of the food in the end gut (arrowhead). Note the autofluorescence of the mandibule. Extended focus images obtained by the camera Leica DFC 300FX and the program Leica Application Suite (Version 3.4.0, package 'Montage'). Intensity, contrast and sharpness were increased with the same strength.