There's a one yellow with pink gills thats about 5cm long, a lot of babies that are white with pink gills around 2 cm long and a few browner ones with gills about 2cm as well.
2013 photos & vids here
eff37 on Flickr
Looks like newt nymphs.No idea on species. Newts across Europe are protected and should not be fished out of ponds and kept in jars. Where did you get them for and can they go back?
Possibly could be Smooth Newt tadpole, pic right at bottom of this Wiki article ... en.m.wikipedia.org/.../Smooth_newt
Just like you Caroline I have been googling & learning all about the lifestyles of various Newts & other related critters ... good way to pass the time whilst it's too hot for housework or gardening!! Lol
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