Multi image tiling of the trophosome area of Paracatenula sp. santandrea

Five specimen of Paracatenula sp. santandrea were fixed with PHEM buffered glutaraldehyde as described by Montanaro et al. (doi: 10.7717/peerj.1860 ) and processed with a high pressure freezer. Samples freeze-substituted in acetone with 1% w/v osmium tetroxide as described by McDonald and Webb (doi:10.1111/j.1365-2818.2011.03526.x ). All samples were embedded in Low Viscosity Resin using centrifugation embedding as described by McDonald (doi: 10.1017/S1431927613013846 ) and ultrathing sections were cut, mounted on slot grids, contrasted with lead citrate and uranyl acetate and then imaged with a Quanta FEG 250 scanning electron microscope equipped with a STEM detector. Images were recorded with a 10-20% overlap to allow reassembly with imaging software afterwards. Each image stack represents one sample.