Just some fun facts that were sitting in a draft article that I will never finish. It's been a year since I last posted on this blog, mostly because I was busy finishing my master's thesis, and partly because I was getting bored with the whole "reporting news" thing. So I'm going to change things up a bit, I think. I'll start posting single interesting articles as I come across them, rather than a weekly digest (which was something of a chore), and I also want to do some fun math/science things.
Most mammals have the familiar red blood that we all know and love. The colour is mostly due to the presence of the iron-based molecule hemoglobin. Spiders have copper-based blood (same as crabs, hemocyanin) which is blue or green or sometimes yellowy. Some worms (Polychaeta) have blood which is green/bright red (chlorocruorin, iron-based), depending on conditions. Some other worms (mostly deep sea worms) have a different colour of red (hemerythrin, iron). Sea squirts and tunicates have a pale green blood pigment (vanadium chromagen, clearly vanadium-based, but with the vanadium possibly in several different oxidation states) which can, depending on other chemicals present be blue, orange, yellow or pink (or basically anything). Some molluscs have brown blood (pinnaglobin, manganese).
There are many others, some of which are mentioned in a neat little book about extraterrestrials. Xenology: An Introduction to the Scientific Study of Extraterrestrial Life, Intelligence, and Civilization.
