Most (proper) fish in a days fishing was 47 chub (from about 2lb - 5lb-080z) from the top swim on the Sheephills section of the Swale.
Highest number of species in a day is 12, believe it or not from the Wear. Chub, dace, roach, bream, perch, barbel, eel, gudgeon, brown trout, sea trout, rainbow trout and a flattie of some kind (not sure what as it was many years ago before a higher weir was built at Chester le Street) We also used to get the large sea lamprey up the river as high as Durham in those days.
If anyone thinks that's high for a northern spate river, the Wear also holds: Brook lamprey, salmon, carp (several types) tench, pike, grayling, along with the usual smaller species,(but never seen/heard of a Tommy R) and I and a friend are sure we have seen a sturgeon in different sections of the river. Dead zander have also been found but these were believed to have been introduced by certain 'specimen' angler a few years back. Unconfirmed catfish have also been reported in the last 12 months