Structure of the Brachionus plicatilis ovary. Light and fluorescent images of the Brachionus ovary. (A-E) Differential interference contrast (DIC) images of whole Brachionus indicating the ovary and other morphological structures. Scale bars indicate 100 μm. Rotifer range from starved adult individuals with greatly reduced ovaries (A) to normal individuals (C), to those with a developing oocyte (D) to those with a large oocyte deforming other structures (E). (F and G) Higher magnification image of a Brachionus ovary (annotated in G) under DIC optics showing the structures of the vitellarium, germ cell cluster and oocyte. Scale bars represent 50 μm. Note: the granules/lipid droplets in the vitellarium and their concentration in the oocyte. (H and I) High magnification mixed confocal/phase contrast image of a Brachionus ovary stained with propidium iodide (red) for nuclei (annotated in I). All of the cell types of the ovary are visible. Scale bars represent 50 μm (J-L) Expression of compounds reactive to DAB and H2O2, producing intense black staining. Staining is in the oocyte and in a tube (asterisks in J and K), passing near the germ-cells, that appears to connect the vitellarium with the developing oocyte. Granular staining is also seen in the vitellarium (arrowhead in J) Scale bars in J and K are 100 μm, 50 μm in L.