Osteichthyes: Immune Systems of Teleosts (Actinopterygii)

Teleosts and elasmobranchs are the lowest vertebrates that possess adaptive immunity akin to mammalian ones. However, the fish immune system is different from that of mammals, that is, a lack of bone marrow, lymph nodes and germinal center. Their immune system is also characterized by the fact that their surface is covered by live cells with mucus in direct contact with environmental water and the fact that the immune response is greatly affected by temperature.