In the early '80's when i was a teenager snakes started to become popular as pets and there were plenty of garter snakes around.
However, i bought two snakes of garter snake size that the pet shop called bronze snakes.
They were a deep bronze colour on top and a yellow colour underneath. But when they were frightened they would puff themselves up and underneath inbetween their scales they were bright blue. They looked beautiful so as kids we used to keep tapping the glass of the tank to make them puff up and turn blue. They used to eat whitebait.
Unfortunately a vet gave me something to bath them in for mites which could be readily seen against the blue, and it killed them.
I am now a vet myself and have never seen these snakes again since and everyone i've spoken to about them has never heard of them.
Many internet searches have failed to come up with anything like it and i now know a herpetologist quite well and he is completely foxed by what they might be.
I know I didn't imagine them!
Does anyone know what they might have been?
Unfortunately I don't have any pictures of them.
I'm not saying that this is the species you had as a kid, but I wouldn't trust a 30-year old memory to be very acurate in all its details, and I would broaden the search a lot, thinking that many of those details may have been generated by my brain over those years.
Thankyou for your help. I have looked at the slow worm and it doesn't look quite like what i had. I know my memory might not remember exactly what the snake in it's relaxed state looked like but it was quite dramatic when it puffed up. You couldn't see the blue at all on the outside at rest it was under and inbetween the scales and could only be seen when the snake expanded and it could almost double the size of its girth to make itself look bigger.
It remains a mystery.
Thanks for your time though.
Just to let you know i have found the snake and it is a common bronze back tree snake from India.
It is exactly how i remember it and I recognised it instantly.
so far i've found:
eastern yellow-bellied racer
yellow-bellied house snake
olive house snake
aurora house snake
and a few pretty ones when i searched for "garter snake blue"... i've been trying to find something promising for nearly an hour haha but to no avail :c this is all i could come up with.
Thank you for your answer. Even though none of your suggestions match my snake I did follow your lead for blue garter snake which led me eventually to the common tree snake of Australia and i think that was it. It varies in colour but says when disturbed it puffs up and shows bright blue skin under the scales. They also eat fish and mine used to eat white bait. As the colour can vary i think this must be it as mine were a bronze colour but the belly was yellow/cream. The pictures look roughly about the right size, very slim and fast moving.
So thankyou for your time and interest, i was beginning to think I was going mad as no one seemed to have heard of a snake that can puff up and go blue. It was quite dramatic and looked beautiful. I assume these could have been imported into this country years ago to be sold for pets.
Actually looking into it a bit more I think it was the common bronzeback tree snake which is from India. The resting colour is more like what I remember mine to be rather than the Australian ones. I have just watched a video of them and they get that flashing blue colour along their body when they puff up. I think this is definitely the snake I had. Mystery solved!