Copper-based blood

[Cheryl]

While watching a Nature program on horseshoe crabs, I was suprised and interested to learn that their blood is copper-based hemocyanin rather than iron-based hemoglobin. I had not previously been aware that there were creatures on earth with copper-based blood. There aren't a lot of such creatures, just horseshoe crabs, a few other arthropods, and mollusks.

I'm excited to learn that copper-based blood isn't just theoretical but a proven possibility. Yay for Anne for not picking an impossibility.

Unfortunately there is a flaw...the hemocyanin causes their blood to be blue when oxygenated, and colorless when not, whereas Anne's dragons have green blood. It makes sense to assume it'd be green, as copper takes on a green patina as it rusts (ie as it chemically reacts with oxygen), but I guess that isn't the case with hemocyanin. On the other hand, there's nothing to say that the dragons don't use different copper-based protein and not hemocyanin.

[Kath]

Oh, it's definitely a possibility! I'm sure Jack Cohen had a hand in helping her work it out, didn't he? Lots of transition metals (like copper or iron) have the capability of forming net-like compounds capable of carrying O2 one way and CO2 the other, and there's even good evidence that Copper might be a more logical choice on Pern. As it's pretty poor when it comes to the heavier elements useful in a high tech society (I'm thinking the transuranics the Theks have such a taste for), the relative abundances of copper and iron would also be likely to be more skewed towards copper than they are here.

[P'ter]

I'd have thought that it was called 'Cuprocyanin' as H(a)em- surely denotes iron?

And anything with cyan- in its name would surely be blue.

[Cheryl]

Nope, it refers to blood.

[P'ter]

I thought it only refers to blood because of the iron content of blood; since WE can't have blood that doesn't contain iron.

[Cheryl]

Iron usually is denoted by ferro- or fer- , isn't it?

[Kath]

Yup. The link with iron (e.g. haematite) goes the other way around - in the case of haematite, it can be reddish and looked like it was bloodstained!

[Topaz the Golden]

I knew that horseshoe crabs had copper blood my little sister was a volunteer at the NYC aquamiurm(sp?). She loves horseshoe crabs and Jellies(jellyfish). Did you know that you can almost drain the blood out of the horseshoe crab with no ill effects on it.

[GHarris]

Originally Posted by Cheryl

While watching a Nature program on horseshoe crabs, I was suprised and interested to learn that their blood is copper-based hemocyanin rather than iron-based hemoglobin. I had not previously been aware that there were creatures on earth with copper-based blood. There aren't a lot of such creatures, just horseshoe crabs, a few other arthropods, and mollusks.

I'm excited to learn that copper-based blood isn't just theoretical but a proven possibility. Yay for Anne for not picking an impossibility.

Unfortunately there is a flaw...the hemocyanin causes their blood to be blue when oxygenated, and colorless when not, whereas Anne's dragons have green blood. It makes sense to assume it'd be green, as copper takes on a green patina as it rusts (ie as it chemically reacts with oxygen), but I guess that isn't the case with hemocyanin. On the other hand, there's nothing to say that the dragons don't use different copper-based protein and not hemocyanin.

That's ok, Star Trek does the same thing. Vulcans have copper based blood which is green.



GH

[Tamara Henson]

Copper-based blood (Hemocyanin) can be found in many arthropods. Hermit Crabs have been mentioned but lobsters, snails, and spiders also have hemocyanin - and both snails and lobsters are definatly eaten. Unfortunatly this blood is more blue than green tough theretically it may be green in other species.

More relevant perhaps is the green blooded skink. As soon as I read about this animal my mind flashed onto Pern's dragons. This is a lizard of the genus Prasinohaema that litterlly has bright green blood.The best known is the New Guinea species P.virens. According to Wikipedia (and I confirmed it by looking it up in several reptile books at the library)..

As in other lizards of the genera Prasinohaema, the blood of P. virens is green, rather than the usual red coloration of most vertebrates. The green blood pigmentation results in a strikingly bright lime-green coloration of muscles, bones, tongue, and mucosal tissue. This coloration of the blood is the result of the accumulation of the bile pigment biliverdin in levels that would be toxic in all other other vertebrates.[2] Biliverdin is a compound that is formed from the breakdown of hemoglobin, and is normally converted to bilirubin. However, it is believed that mutation in various genes regulating bilirubin formation lead to the formation and accumulation of high levels of biliverdin

Some sites claim this lizard is toxic but in actuallity it simply taste so bad predators avoid it. Never heard that wherries taste horrible but it is possible that Pernese vertebrates have a similar chemical or that the chemical is unique to dragons, firelizards, and whers.

[Kath]

Originally Posted by Tamara Henson

More relevant perhaps is the green blooded skink. As soon as I read about this animal my mind flashed onto Pern's dragons. This is a lizard of the genus Prasinohaema that litterlly has bright green blood.The best known is the New Guinea species P.virens. According to Wikipedia (and I confirmed it by looking it up in several reptile books at the library)..

Some sites claim this lizard is toxic but in actuallity it simply taste so bad predators avoid it. Never heard that wherries taste horrible but it is possible that Pernese vertebrates have a similar chemical or that the chemical is unique to dragons, firelizards, and whers.

That's a lovely picture!

I don't know about Wherries, but at least some of the Pernese snakes taste pretty foul - perhaps for a similar reason?

[GinnyStar]

Originally Posted by Tamara Henson

More relevant perhaps is the green blooded skink. As soon as I read about this animal my mind flashed onto Pern's dragons. This is a lizard of the genus Prasinohaema that litterlly has bright green blood.The best known is the New Guinea species P.virens. According to Wikipedia (and I confirmed it by looking it up in several reptile books at the library)..

As in other lizards of the genera Prasinohaema, the blood of P. virens is green, rather than the usual red coloration of most vertebrates. The green blood pigmentation results in a strikingly bright lime-green coloration of muscles, bones, tongue, and mucosal tissue. This coloration of the blood is the result of the accumulation of the bile pigment biliverdin in levels that would be toxic in all other other vertebrates.[2] Biliverdin is a compound that is formed from the breakdown of hemoglobin, and is normally converted to bilirubin. However, it is believed that mutation in various genes regulating bilirubin formation lead to the formation and accumulation of high levels of biliverdin

Some sites claim this lizard is toxic but in actuallity it simply taste so bad predators avoid it. Never heard that wherries taste horrible but it is possible that Pernese vertebrates have a similar chemical or that the chemical is unique to dragons, firelizards, and whers.

That why some of the snakes are eatable, and some are not.

The way the muscles in dragons is told about in Moreta when she is reparing the High Reach Sr. Queen after her own queen had cluched.

Also I've been think that the spiderclaws and laying eggs in the sand is more like the horsreshoe crabs in laying eggs, then crabs in self, and shell fish an I don't get along