An are large Y-shape protein produced by plasma cells that are used by the immune system to identify and neutralize foreign objects such as bacteria and viruses. The antibody works recognizes a unique part of the foreign target, called an antigen.
This assignment is in reference to why it is accurate to say that a fish has a better immune system than a jellyfish.
This is my response:
Jellyfish immune systems are focused on physical defense, such as stinging which is the same mechanism that they use while feeding. Their endocrine system in relation to internal immunity (the B and T cells) is rather superficial due to their simplicity in structure. Fish have both internal and external defense mechanism, their external mechanism consist of scales that inhibit bacteria and the thin mucous membrane with antiobiotic qualities in their oesophagus membrane and scale covering as well as their eyes. It helps slough off debris and discourages parasites from attaching themselves to the fish. Their internal defense is made up of C-interferos that attack bacteria and viruses in the bloodstream
Also jellyfish have an open circulatory system and a gastro-vascular cavity where digestion takes place. Then, nutrients from digested foods brought into cells in the animal's simple body. Where as fish have closed circulatory system. Animals must be able to circulate antibodies in the closed circulatory system in order to keep up a strong immune system.