Eastern red spotted newt, or Tiger salamander?

[pent565]

At what age can one tell the difference? I rescued some caudate larva from a quickly drying ditch (stupid parents), and in my area both are native, though I haven't actually seen any adults of either species. I am tempted to assume tiger salamander, as it was a ditch, not a pond with adults, but at the time it was raining a lot, and had a tenuous connection to a pond/swamp system in the woods.

I'll try to get some pics up, but for now as far as behavior goes, these guys are eating anything in front of their faces. I'm feeding them plenty of bloodworm, yet the four I have left still cannibalized the other fifteen or so. All four are the same size, so I'm past that danger, I just wish I'd noticed the trend in time to set up a cycled tank to separate them. They stay at the bottom, though I have some floating plastic plants in there. Three are mostly dark black, while one has developed a muddy brown color, almost reddish, which had me hoping eastern newt.

How big should I expect either species to get before they ditch their gills?

 

[Kaysie]

You will be able to tell at hatching. These two are quite different.

Easterns are usually 1-2 inches when they morph. Tigers are 5-6 inches. It's the end of July now, so they'll be close to morphing size. That should clue you in on species too.

Both are terrestrial when they morph, especially Easterns. Efts are terrible swimmers.

 

[pent565]

well, if they should be close to morphing, they're nowhere near 5-6 inches. Barely one inch, but then I'm in NS, our summers start later than other places.
Oh, and a new possibility occurred to me. They could be yellow spotted salamander eggs. I always assumed those were tiger salamanders, what with the whole looking the same thing. Are they in fact different?

 

[Kaysie]

I'm from Michigan, so most of my memory of this stuff comes from 'the north'. Even in Nova Scotia, there will be a serious size difference between tiger sals and Notos at this point. Tigers will be way bigger than an inch. Heck, they're over 1cm when they hatch!

Spotted salamander egg masses are very distinct. They're distinct, extremely cohesive clumps of 20 to 200, ranging from clear to opaque milky white to cloudy green (especially in masses getting ready to hatch), attached to sticks. Tiger salamander egg masses are usually smaller, and less cohesive.

 

[Coastal Groovin]

I'm guessing you found them in NS. They could be blue spotted, eastern newts,yellow spotted salamanders or four toed They should be morphing this month or next. Nova Scotia does not have tiger salamanders. Since you found them in a smaller area of water and not the main pond they maybe Four Toed (Hemidactylium scutatum) or a eastern newt. Here is a link to a picture of a four toed larvae http://www.arkive.org/four-toed-salamander/hemidactylium-scutatum/image-G113879.html to help you out.

 

[pent565]

definitively not the four toed. Blacker from the start. I could swear we have tiger salamanders in ns, they're just uncommon. Dad found one with its tail stuck under a garage door once. I was a child at the time, but I remember how huge that thing was. Do we really have blue spotted around here? At the moment I'm strongly thinking yellow spotted, since they're the only ones I've seen other than red-backs.

 

[pent565]

The google image ones all look the same... .