Not to criticize at all, because I used to catch frogs, etc., and keep them as pets when I was younger myself: but in most cases it's really best to leave wild animals in the wild, especially if you don't know exactly what they are, if they are a fragile population, or if you're not sure exactly how to care for them. Far too often they end up dead because you don't know how to care for them correctly. Enjoy them by observing them in the wild, or AT MOST catch it to observe it for a couple days in a tank, and then let it go again. Then go to your petstore and get a salamander there that has been bred for the pet trade, and that you can recieve good instructions on how to care for it. This is what I wish I had done in some instances in the past, when I killed a wild caught animal, and couldn't help but feel guilty for taking it out of its native home to die in a tank...
Vernal pool habitats are also not the most common, and in some cases may need all the help they can get to maintain their biodiversity and health.
Just my two cents, as a past 'offender' myself.
Edit: One last thought; A lot of reptiles and amphibians worldwide are threatened in the wild because of overcollection for the pet trade, and collection for personal pets. I'd just as soon not contribute to that problem...