Cnidarians

These are invertebrates that are radically symmetrical, meaning the halves of the body are identical. Cnidarians have stinging cells in their tentacles that they use to protect themselves and paralyze their prey. There are 10,00 species, and some examples are Pillar coral (Dendrogyra cylindricu) and Hydra (Hydra vulgaris).

Flat Worms

These are soft, paper thin invertebrates with a brain smaller than a cluster of nerves. They are either parasitic, feeding on and laying eggs on host, or free living, eating smaller organisms and dead meat. There are about 20,000 species and some are Tapeworm (Cestoda) and Planaria (Planariidae).