A Comparison of the Innate and Adaptive Immune Systems in Cartilaginous Fish, Ray-Finned Fish, and Lobe-Finned Fish.

Abstract in brief

• The immune system in vertebrates consists of two parts: the innate immune system, which is the first to respond to pathogens and does not remember past infections, and the adaptive immune system, which targets specific pathogens with memory for future defenses.
• The review compares these immune components across different fish groups—cartilaginous fish, ray-finned fish, and lobe-finned fish—and highlights both the conserved elements and notable differences in their immune systems, including physical barriers, immune cells, and molecules like immunoglobulins and MHC.
• Studying the immune systems in various fish species helps scientists understand how immune defenses evolved over time in vertebrates, providing insights that are relevant to higher animals, including humans.