A walk in the hills today

[mark]

The habitat. South Wales hills - a frozen pond, altitude 800m, air temp -2 C.

In the pond are lots of last years 1 inch long larvae, still active under the ice but slow enough to catch for a photo. Probably Lissotriton vulgaris but I'm no expert. I was surprised they were surviving.

 

[francesco]

looks more t. cristatus to me. You can tell by the long toes. Do you get all 3 species in that pond?

 

[mark]

I don't know, it was the first time I've see this pond and I wasn't expecting to see anything. Do Triturus often overwinter in ponds? There were a mixture of light and dark larvae. I couldn't get near the dark ones without getting wet feet and in sub-zero temps I didn't fancy that!

 

[philip]

there are still lissotriton vulgaris larvae in a local pond near me. we are only a couple of hundred feet above sea level, near manchester. but a few miles away and 500 feet higher is a pond containing only lissotriton helviticus, but i could find no late larvae in there. maybe all the helviticus bred earlier than the vulgaris last spring. i have bred both species, and there appears to be no difference in the time needed for metamorphosis

 

[alan]

They often overwinter in ponds where the water is cold, so the larvae grow more slowly. I suspect they are vulgaris too.

 

[william]

i would say helveticus at that hight Mark.

Francesco- it's certainly not a cristatus, it isn't dark enough. and the toes aren't long enough

 

[francesco]

since I can't see any spots on the tail maybe you're right but colour isn't a good key cos it varies depending on which substrate and temperature they are.

 

[francesco]

Mark
have you got any other photos of it?

 

[mark]

I did take a few others but I’m not sure they will help. There are no markings as such and the tail fin is very small. My guess is that larvae in cool ponds, that are forced to over-winter develop differently to those that grow fast in warmer water. The head shape is that of a very young larvae, considering that it’s probably 6 months old. The legs are quite well developed and the tail fin has shrunk already. I would expect the tail fin to shrink just before metamorphosis, but these larvae were far from that.

I’ll check the other pics when I get in tonight.

 

[william]

Francesco the fact that the larvae is a brown colour also suggests the fact that it's a lissotriton rather than triturus. also the lack of body spots indicates this and lack of a blue rim to the tail.

 

[mark]

 

[francesco]

what size is it?

 

[mark]

~2.5cm

 

[rubén]

Interesting finding

The delicate aspect and proportion of legs, head and tail, beyond the stained diffuse of small dots, makes me think in Lissotriton too. Probably this larvae have more than 1 year...

Anyway, what altitude reaches Triturus cristatus in England?

Mark _ I'm not surprised anymore about the resistance to the cold of the newts... recently I have been able to see T. marmoratus under a thin layer of ice...

(Message edited by iberian_guest on January 26, 2006)

 

[william]

Ruben, i personally don't know any figures, but Triturus cristatus is generally associated with lowlands, Lissotriton helveticus with high ground (but that's not to say that it isn't found in lowlands as well) and Lissotriton vulgaris is both, but it is far commoner in the lowlands than uplands.