Which animal groups have nematocysts, a water vascular system, or a hollow dorsal nerve cord?

In the context of biological morphology, the specific animal groups associated with these features are as follows:

• Nematocysts: These specialized, stinging intracellular capsules are produced exclusively by members of the phylum Cnidaria, which includes animals such as jellyfish, corals, sea anemones, and Portuguese men-of-war.12
• Water vascular system: This system is a characteristic feature of echinoderms, such as starfishes, sea urchins, and sea cucumbers. It consists of a series of fluid-filled canals derived from the coelom that function in locomotion and respiratory exchange.3
• Hollow dorsal nerve cord: This is a defining characteristic of the phylum Chordata. The phylum includes vertebrates, tunicates, and cephalochordates, all of which possess a nerve cord located dorsal to the gut at some stage in their life cycle.4