Anolis carolinensis hatchling in our animal facility.
I’ve noticed that many of the anoles in my breeding colony occasionally have white protuberances emerging from their nostrils, like the two-month old hatchling to the left. I haven’t been able to determine whether these protuberances are the remnants of an old shed or whether the lizards have a fungus growing in their nostrils. By the time I catch an afflicted individual in its cage the protuberances are gone, seemingly because the lizard blew them out while moving to evade my hand. Has anyone experienced this phenomenon?
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Yoel, nasal salt secretions are fairly common (so I am told). (http://www.ncbi.nlm.nih.gov/pubmed/20623801) Off hand I recall observing similar secretions on A. maynardi and A. cybotes over the last few years. I don’t often see them on my captive animals, however.
That looks like salt. Most (all?) reptiles have salt glands in the nose and will, under certain conditions, get a crusty buildup around the nostril.
Here are a couple of references to get you up and running:
Peaker, M. and J. L. Linzell. 1975. Salt glands in birds and reptiles. Cambridge University Press.
Hazard, L.C., C. Lechuga and S. Zilinskis. 2010. Secretion by the nasal salt glands of two insectivorous lizard species is initiated by an ecologically relevant dietary ion, chloride. J Exp Zool A Ecol Genet Physiol. 313:442-451.
Hazard, L.C. 2001. Ion secretion by salt glands of desert iguanas (Dipsosaurus dorsalis). Physiol Biochem Zool. 74:22-31.
Hazard, L.C. 2004. Sodium and potassium secretion by iguana salt glands: Acclimation or adaptation? Pp. 84-93. In: Iguanas: Biology and Conservation. A. Alberts, R.L. Carter, W.B. Hayes, and E. Martins, editors. University of California Press.
@Thom – I’ve noticed them in A. cybotes, too! One qualitative observation – these appeared to be more common in the A. cybotes I was keeping in the cold room (20C). If they’re salts, any suggestion that their prevalence should increase with decreasing temperature? I worried about a fungus, too, and spent some time cleaning schnozes.
Ahhh. Salt! Thanks for the information and links. Good to know that it isn’t a fungus!
@ Yoel – Taste it next time. =)
@ Martha, this is a little surprising to me as nearly every A. maynardi I observed on Cayman Brac had them on hot days and very few had them on cool days. But again, this is just a casual observation.
Yes, this is definitely salt. My personal observations over 20+ years of anole husbandry are that the secretions increase when anoles are slightly dehydrated. I assume this is a way to regulate water and salt balance in the body.
I’m interested to know if others have noticed a positive correlation between the nasal salt secretions and dehydration as more salt secretions with dehydration seems counter-intuitive at first (as salt helps with water retention; at least in mammals). Any ideas, herpetologists?
I have actually seen that also in Anolis sagrei in the wild here in Taiwan as well.
The 2010 article by Hazard et al. (as mentioned by Tony earlier today) studied nasal secretions from A. carolinensis in response to 4 days of daily injections of various combinations of cations and anions vs. sham control. They concluded that “…anoles secreted solely in response to chloride, rather than potassium, sodium, or other osmotic challenges…Anoles secreted
entirely potassium, even when sodium-loaded, and appeared to secrete entirely chloride, suggesting that their glands are highly specialized for potassium chloride excretion.”
Salt secretion in response to dehydration could make sense. Dehydration would cause the ion concentration in the blood to increase, and the little anole hypothalmus would probably detect that and try to get rid of excess salt to maintain homeostasis.
Salt does help with water retention in mammals, but not in lizards. This is due to differences in the structure of the mammalian and lizard kidneys. Mammalian kidneys have structures called a loop of henle (which utilize salt movement across membranes), but lizard kidneys don’t. The result is that mammals can create urine with a high salt concentration (by retaining water), but lizards can’t.
Hmmm. I think we’ll have to up the amount of water we spray into the cages every day then. We mist moderately twice a day but our lizard room is fairly dry now that winter has set in. For those battling similar issues, see the Glor lab’s series on The Evolution of a Lizard Room for discussions of watering and humidity (https://anoleannals.wordpress.com/2011/11/03/evolution-of-a-lizard-room-part-ii-maintaining-humidity/).
Thanks all for the discussion!