Illness/Sickness: White specs on wild newt

[clizzzo]

imgur: the simple image sharer

I found this newt on my way home from the pub and he looks like he's suffering with some kind of infection. Thought this was strange.. he was living under a bridge no where near any pools of water.

Does anyone know what's up with him and if this is normal for wild newts?

 

[slowfoot]

The newt looks healthy - they actually spend quite a bit of time out of water - and the white spots look like toxic skin secretions. Usually these are expressed in response to being handled or attacked. That's my best guess.

 

[clizzzo]

Ah yeah he was generally being an idiot, playing dead and stuff so he probably didn't like being handled. Glad to know there's not some nasty new fungus or something going around killing all our newts!

 

[jAfFa CaKe]

I have never seen a smooth newt secrete poison like that before! Nice pictures.

 

[sde]

Very cool! I love it when amphibians secrete poison :wacko:

 

[Chinadog]

No, me neither, but to be fair most smooth newts i've handled have been in the aquatic phase. Maybe it's something they only do when terrestrial?

 

[jAfFa CaKe]

Maybe, but around me the ponds are all closed off. So I normally find a lot of terrestrial Vulgaris. But still, I've never seen it like that. The only places I find Vulgaris in the aquatic phase is in my pond.

 

[Alpestris350]

I'm very sure Lissotriton Vulgaris do not have toxins or at least any toxins which they can release like that (I have handled them/observed them for quite a few years in the wild) Having said that, I can't think of what that could be. Maybe it's water droplets with some white colouration/texture in it from dust or something?

 

[Alpestris350]

Also, there looks to be some damage/growth on the bottom right leg? The skin in my opinion looks damaged along the newt's sides unless it is water/light.

 

[jAfFa CaKe]

Yes, you are correct on the leg thing. I, to, didn't know that L. Vulgaris could excrete poison but that looks exactly the same as any other poison being excreted from other caudates.

 

[sde]

It doesn't look much like the poison I have seen caudatas secrete, usually its more runny. But it definitely looks like poison, what else could it be?

Its back leg is busted up pretty good like Alpestris said. Maybe it was attacked by some animal or something and secreted poison as a defense? Maybe simply handling it isn't enough for this species to secrete poison, but if provoked enough maybe it does?

One thing that caught my eye was on its tail there is clearly another white substance. You can see it best in the second picture. It is flat, like the poison I often see in A. gracile, and looks more like milk. The 'dot poison' couldn't be fungus, its too uniform...sooo...I have no idea, other than that it actually is poison. Seems reasonable enough to me. -Seth

 

[Alpestris350]

I agree it doesn't look too different from toxins produced by other salamanders. However, wouldn't they possess aposematic colouration to try and warn predators that they're toxic (otherwise it's pretty useless?). And their colour suggests to me that they try to camoflauge. Also, wouldn't they need paratoid glands to release toxins like that?

 

[caleb]

I agree it doesn't look too different from toxins produced by other salamanders. However, wouldn't they possess aposematic colouration to try and warn predators that they're toxic (otherwise it's pretty useless?). And their colour suggests to me that they try to camoflauge. Also, wouldn't they need paratoid glands to release toxins like that?

No, they don't need parotoid glands- other newt species will release toxins from their skin just like this.

Smooth newts do have bright yellow or orange bellies, which could be a warning colouration. They have been known to show this colour by 'unkenreflex' when threatened. Plenty of toxic newt species (e.g. Taricha, Cynops) are similarly dark above and bright yellow, orange or red below.

Smooth newts' secretions have actually been shown to be more toxic than those of great crested newts, which are well known for their toxicity. I'll try to post the reference later.

If anyone wants to know what it's like to nibble on a toxic newt, I'd recommend reading Eleanor Ormerod's account from 1872:
Observations on the Cutaneous Exudation of the Triton cristatus, or Great Water-Newt. By Miss Eleanor A. Ormerod.

 

[jAfFa CaKe]

It doesn't look much like the poison I have seen caudatas secrete, usually its more runny. But it definitely looks like poison, what else could it be?

Its back leg is busted up pretty good like Alpestris said. Maybe it was attacked by some animal or something and secreted poison as a defense? Maybe simply handling it isn't enough for this species to secrete poison, but if provoked enough maybe it does?

One thing that caught my eye was on its tail there is clearly another white substance. You can see it best in the second picture. It is flat, like the poison I often see in A. gracile, and looks more like milk. The 'dot poison' couldn't be fungus, its too uniform...sooo...I have no idea, other than that it actually is poison. Seems reasonable enough to me. -Seth

I think the other liquid on the tail is just where the poison drops have given way and spread out? Or maybe it is something else. Either way, this thread continues to intrigue me.

 

[caleb]

Smooth newts' secretions have actually been shown to be more toxic than those of great crested newts, which are well known for their toxicity. I'll try to post the reference later.

Chemical Zoology vol. 9, 1974, edited by M. Florkin & B. T. Scheer gives these subcutaneous LD50 values for mice (which I've arranged in decreasing potency):

Tetrodotoxin (from Taricha torosa) 8 ug/kg
Samandarin (from S. salamandra) 1500 ug/kg
T. marmoratus toxin 1800 ug/kg
L. vulgaris toxin 6700 ug/kg
T. cristatus toxin 20000 ug/kg

They also state that vulgaris, cristatus, alpestris and marmoratus 'possess secretions of an amazingly high hemolytical activity'.

Obviously if smooth newts only produce tiny amounts of their toxins then they're unlikely to be harmful to predators (and there are certainly lots of predators that do eat them), but they clearly do produce rather toxic substances.

 

[Alpestris350]

Chemical Zoology vol. 9, 1974, edited by M. Florkin & B. T. Scheer gives these subcutaneous LD50 values for mice (which I've arranged in decreasing potency):

Tetrodotoxin (from Taricha torosa) 8 ug/kg
Samandarin (from S. salamandra) 1500 ug/kg
T. marmoratus toxin 1800 ug/kg
L. vulgaris toxin 6700 ug/kg
T. cristatus toxin 20000 ug/kg

They also state that vulgaris, cristatus, alpestris and marmoratus 'possess secretions of an amazingly high hemolytical activity'.

Obviously if smooth newts only produce tiny amounts of their toxins then they're unlikely to be harmful to predators (and there are certainly lots of predators that do eat them), but they clearly do produce rather toxic substances.

That is impressive. I doubted they produced toxins because I had never seen them do so nor seen a page which has suggested that these newts do produce harmful toxins. They are in the 'Least Toxic' category of salamander species?
Caudata Culture Articles - Newt Toxins

 

[caleb]

They are in the 'Least Toxic' category of salamander species?
Caudata Culture Articles - Newt Toxins

Yes, mainly because the most toxic species are very very toxic indeed. There was an interesting thread a while ago started by a forum member who was poisoned by N. kaiseri:

http://www.caudata.org/forum/f1173-...urergus/81129-kaiseri-poisoning-incident.html

Reading Eleanor Ormerod's account, it's clear that even those 'least toxic' species can cause rather unpleasant poisoning.