Three forms of vertebrates are commonly found in caves – fish, amphibians and bats, although they are either accidental or using them for shelter. It is thought there is not enough food for them to survive as troglobites in UK caves.

Fish
Bullheads Cottus gobio and blanched brown trout Salmo trutta are often found in caves in Britain, especially in Wales and Yorkshire.
Salmon Salmo salar have been reported in Hurtle Pot, but may have been introduced by man.
Trout Salmo trutta have been reported in a number of caves including Ingleborough Cave, Gaping Ghyll, Hurtle Pot, Rowten, Upper Long Churn, Fairy Holes (Weardale), Bruntscar (this one was nicknamed Dick and fed by cavers). Many of these fish appear white in the caves but this depigmentation is a temporary condition and the colour is restored in daylight. The row of pink spots remains on the white fish however.
Bullheads Cottus gobio have been recorded in Gaping Ghyll.
There are other recordings of fish in Great Douk, Swinsto, Alum sump, Borrins Moor, Rowten sump.
The Eel Anguilla anguilla is a third species that is encountered underground, it is common in the Dentdale phreatic zone.
For non-divers a good place to see fish is to creep down to the water in Hurtle Pot and peer into the water.

Amphibians
Common Frogs Ranus temporaria can be found underground. Those in vertical entrances are accidental visitors and often look thin and starved, although there are exceptions though such a large healthy looking specimen in Lost Johns in the sump below Pinnacle Pitch. Presumably it had come in via the stream and had either survived the drop down Monastary and Pinnacle Pitches, or had come in as frog spawn and lived in the cave since then.
Those in horizontal systems may have chosen to be there and be able to leave the cave easily when desired, these may appear well fed and healthy.
Specimens have also been seen a long way underground  e.g. terminal lake in Ingleborough cave and healthy specimens have been seen 1km into the sump.

Common Frog Ranus temporaria in Mistral Hole