Uromastyx.org

Here is a good article on the lymph sacs I mentioned previously to LMS.

http://jeb.biologists.org/content/121/1/165.full.pdf

legend! thanks T

what a brilliant peice of work. ive only just started reading it but will enjoy studying the peice

im still reading it and omg, its amazing isnt it. the function of the lymph sacs being that the osmosis like transfer occurs most when their is less fluid stored and therefore makes survival more likely, that is as if awaiting fluid from rain etc.
it makes sense that sacs reduce most in the first few days as their digestive system is sustaining a particular pattern and thus must adjust gradually opposed to a dramatic change in fluid content in the body which would cause digestive complications. but the values in the stored fluid are not so concentrated as the body will still retain these from internal fluids.
what i would like to know is how the constant use of this body function affects their overall health in the long term. obviously regular periods of dehydration will shorten life span but are there any other reactions to the operations of the lymph sac fluid retrieval system? such as eyesight and brain function?

also what other behaviours would associated to this biological function in wild observations.

goes to show that we must be very careful when using medication to treat chucks for things like parasites as we must take into consideration water rentention weight.
also that having a high moisture content diet in captivity doesnt appear to have a detremental impact as they will adapt to the level of mostire in their diet with ease once regularity is confirmed.

and perhaps that dehydration in chuckwallas is not as immediatley fatal as it is in other species.

does anyone know anything about the evoluntionary history of sauromalus? it would be interesting to know how far back in history the species goes as they are so highly adapted. surely it would like a very long time for them to estbalish this bilogical function so effectively?

Look for the work of Brad Hollingsworth. He did a paper on chucks that was great that I think talked about fossil record etc. Not sure of the title of the article but it was long. From maybe the late 90's

Thanks Tom!
I love learning about chucks. Love everything about them!

Hollingsworth, B.D. 1998. The systematics of chuckwallas (Sauromalus) with a phylogenetic analysis of other iguanid lizards. Herpetological Monographs 11:38-191.