I dont have much information regarding them either but where we live (south florida, USA) we have lots of those type of tadpoles, regular black/brown ones and even some spotted and striped ones... they have been there for as long as i can remember (new life cycles obviously) Ive never seen one morph into a white frog though.. perhaps they die before morphing into adult frogs or we just missed seeing them evolve. I cant imagine though that over the course of 20 years (we started tadpole hunting when i was about 3-4yrs) that there would be an increase or decrease in pollution causing the white tadpoles, they have been there all along, perhaps its just a type of species...perhaps because your half a world away it could be something totally different?

Good luck with it! I cant wait to see what it looks like as it grows. Congrats to your daughter on a neat find They sure are cool.