Triops is a genus of small crustaceans in the order Notostraca (tadpole shrimp). Some species are considered living fossils, with a fossil record that reaches back to the late Carboniferous, 300 million years ago. One species, Triops longicaudatus, is commonly sold in kits as a pet.
Innate immunity is found in both animals with and without adaptive immunity. The molecular components of the innate immune system do not appear to be closely related to the molecules of the adaptive system.
1 Innate (nonspecific) system responds quickly and consists of: 2  First line of defense - intact skin and mucosae prevent entry of microorganisms. 3  Second line of defense - antimicrobial proteins, phagocytes, and other cells.  Inhibit spread of invaders throughout the body.