Cnidarian Immunity: A Tale of Two Barriers -- Gastropod Immunobiology -- Bivalve Immunity -- Earthworm Immunity -- Leech Immunity: From Brain to Peripheral Responses -- Innate Immunity in C. elegans -- Immunocompetent Molecules and Their Response Network in Horseshoe Crabs -- Tick Innate Immunity -- Beetle Immunity -- Immunity in Lepidopteran Insects -- Fly Immunity: Recognition of Pathogens and Induction of Immune Responses -- Mosquito Immunity -- Crustacean Immunity -- Echinoderm Immunity -- Urochordate Immunity. It can be seen that the insects are the still attracting most research and researchers. However, an increasing interest is emerging to study new invertebrate groups, especially those where the genome is known. Even though Drosophila has been and still is an excellent model for immune studies, it is now clear that there are great differences between immune responses in Drosophila and that of several other invertebrates, which indeed calls for more research on other invertebrates