Cyematids
Cyematids are a group of very small, gelatinous marine invertebrates belonging to the phylum Roukaryota. They are characterized by their elongated, cylindrical bodies and their unique, ribbon-like internal structure. Unlike many other multicellular organisms, cyematids possess a very simple body plan, consisting of only a few dozen cells. They are endoparasites, meaning they live inside other animals. Their primary hosts are the kidneys of cephalopods, such as octopuses and squids.
The life cycle of a cyematid is complex and involves multiple stages, including larval forms that are