Haemocyanin & Sight?

HybridReplicate

Spectrostatic
Joined
Jan 26, 2017
Messages
107
I'm reading about tarantula blood (haemolymph doesn't have quite the same ring) & spectroscopy shows significant absorption at 350 & 580 nm. I recalled when reading about tarantula's eyes that the presumed visible spectrum is dual-sensitivity, with a primary near 500 nm & a secondary near 370 nm.

Coincidence?
 

Olan

Arachnoangel
Old Timer
Joined
Dec 23, 2002
Messages
794
Probably coincidence. The wavelengths they can see are due to the photoreceptors in the eye, and the wavelength absorbed by the blood is due to the heme-containing oxygen carrying proteins. I highly doubt tarantulas use the same proteins for both functions.
 

viper69

ArachnoGod
Old Timer
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Dec 8, 2006
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12,372
.

Coincidence?
Yes it is.

The proteins used for vision are not the same proteins used in oxygen transport, not even close. They aren't even in the same family, nor do they have copper in them as do hemocyanins.
 

HybridReplicate

Spectrostatic
Joined
Jan 26, 2017
Messages
107
I would be interested in any sources you could direct me to that go into tarantula A&P in some depth.

My thought was more along the lines of a problem with the experimental protocol, perhaps contamination or somesuch. Improbable, but I read anecdotal reports of tarantulas reacting to red light before transitioning to haemolymph. The more likely explanation is variation in species.
 

viper69

ArachnoGod
Old Timer
Joined
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12,372
I would be interested in any sources you could direct me to that go into tarantula A&P in some depth.

My thought was more along the lines of a problem with the experimental protocol, perhaps contamination or somesuch. Improbable, but I read anecdotal reports of tarantulas reacting to red light before transitioning to haemolymph. The more likely explanation is variation in species.
If you google tarantula vision, you will come upon a paper done with a N. American genus. It's a primary journal article.

Your anecdotal reports are wrong. Tarantulas do not see into the red part of visible spectrum.

I have no idea what you mean by "transitioning to haemolymph"??
 
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