More fish from the River Lea at Stanborough Park, Welwyn. I'm not great at identifying fish (you seldom see them clearly anyway unless you're an angler) but I reckon these are Dace. Quite slim and sleek, with a large eye compared to the Barbel in my previous post from the same spot, though not quite as big. here's another shot with one of each (I think) Barbel above, Dace below – each perhaps 25cm long. Or maybe I've got three species here in total?

Update: having found a good book on dish with photos, they could easily be Chub instead of Dace.