Fig. 2.

Cnidocytes in the Hydractinia feeding polyp. (A) High-concentration DAPI staining shows the distribution of cnidocyst-capsule containing cnidocytes in the oral half of a feeding polyp, where mature cnidocytes (in white) are densely packed in the tentacles, and less dense in the hypostome and body column. (B) Double HCR-FISH of two mature cnidocyte markers (HyS0002.245 in cyan, HyS0027.82 in magenta) shows spatial location in the oral half of a feeding polyp. (C) Zoom-in of a single tentacle showing location of putative desmonemes and euryteles. (C’) Zoom-in showing the two mature cnidocyte markers together with DIC to highlight cnidocyte capsules. Nuclei stained with Hoechst are shown in dark blue. Scale bars are 50 µm in A and B and 10 µm in C and C’. Asterisk in A and B indicates the mouth.