the heart of cray fish also seems to be of particular interest.
Interesting tidbit about open circulatory system I found from the site -
Open circulatory systems (evolved in crustaceans, insects, mollusks and other invertebrates) pump blood into a hemocoel with the blood diffusing back to the circulatory system between cells. Blood is pumped by a heart into the body cavities, where tissues are surrounded by the blood
on hemocyanin from this study
These results show that hemocyanin of crayfish is involved in several immune responses such as an oxygen carrier protein, as a precursor for an antibacterial peptide, and a molecule with phenoloxidase function.These results show that hemocyanin of crayfish is involved in several immune responses such as an oxygen carrier protein, as a precursor for an antibacterial peptide, and a molecule with phenoloxidase function.
For whatever reason most of the research seems to be around late 90s early 00s, I guess there was some particular motivation for looking into them around that time. It seems to given rise to a lot of discoveries in ecological immunology research.
I think the most interesting thing looking into it is all of the trade offs and upkeep in the immune system of these types of organisms. I guess Crayfish may live in extreme conditions so that could be part of the reason we look at them?