Chapter 12 of Oar Feet and Opal Teeth covers egg to adult development of copepods
Chapter 12 of Oar Feet and Opal Teeth covers egg to adult development of copepods. It includes a section on how stone-like teeth, clasped like jewels in chitin bezels, come to sit on the outside of the mandibular exoskeleton. Long ago, coauthors and I wrote a paper 1 to summarize our work toward understanding the process. Recently, while discarding old files, I found some transmission electron micrographs (TEMs) we did not publish. Perhaps that was because of some displayed gaps in tissue preservation. However, these sections cut along the cores of the “duct” we believed carries a silica-bearing substance from a gland at the base of the mandible to the fibrous tooth molds on the developing jaw edge (Figure 12.19B in Oar Feet and Opal Teeth ). Duct is in quotes, because there seems to be no actual lumen. The sections (Figures A & B) show the ducts’ distinctive structure of osmophilic (osmium staining) “lamellae.” Those appear to have been moving oval inclusions toward...