This is fascinating. I spotted this place by accident and had to Google what I was looking at.
Turns out these fascinating little creatures are tadpole shrimp! There's only TWO groups in the UK - New Forest pond and a pond in Scotland. I'm not sure which of the sub-types they fit into but most likely "simplex". They're extremely endangered in the UK as a result.
Of all the shrimp to land on by accident it was one of the most fascinating for a Brit! Subscribing - thanks!