PMC

Hirudo verbana Digestive Tract. Schematic of the leech digestive tract (modified from and ). The ingested blood meal is stored in the crop where it forms a highly viscous intraluminal fluid (ILF) consisting of densely packed erythrocytes (dark circles surrounded by autofluorescence, examples indicated with arrow heads in insets). Fluorescence in situ hybridization micrographs of the leech crop describe (A) thick layers of mucus (red arrows) near the crop epithelium (dashed line) that develop after feeding and (B) circulating hemocytes (blue arrows) within the ILF that contain bacterial cells (green arrows). DAPI (blue), sWGA (red), and EUB338 (green). Scale bars = 10 μm.