I've kept them in the past. They are lots of fun to watch, but the feeding is a hassle. I never could get them to eat anything but live bloodworms. I'm not sure of their life expectancy but I've never had one live longer then a month. Having arms and legs seems to make it a bigger let down when they die... That's probably just me though.
What was it you could not keep alive the Dwarf frogs or the dwarf sirens?
I kept my dwarf aquatic frogs for few yrs , remember they loved blood/tubifex worms even the dry cubes but never kept dwarf sirens.
I know nothing about them but have read the northern dwarf (Pseudobranchus striatus) is difficult but the Florida dwarf (
Pseudobranchus axanthus) has even been bred in captivity.
I looked up the scientific names as don't know it off hand lol.
I saw the Florida dwarfs in a pet store and they were neat .The guy had them for few months . I think it is illegal to sell native fauna in same state but than again this is Florida lol.