A tropical fish usually found in the Amazon Basin in South America has been discovered in a Black Country canal.
The leopard pleco, from the catfish family, was spotted by contractors who had drained Walsall Canal for maintenance work.
Sold to eat algae off the side of tanks, it is thought someone has dumped the unwanted fish in the waterway.
The Canal and River Trust believes it must have been recently as it would not have survived a winter.
John Ellis, national fisheries and angling manager with the trust, said the fish - which has not been sexed - had done well not be eaten by a native pike.
The canal was drained between lock one and two for the work by MEN Fisheries on 7 August and an electric current passed through the water to temporarily stun the fish so they could be gathered in a net and removed.
"You'd expect to find the normal, native species when doing this, like perch, bream, or roach," he said.
"But this was totally out of the blue.
"At first, the contractors thought it was a bull head - a native fish that is quite rare to find as they've suffered from pollution - but when they were looking at it, it was nothing of the sort.
"They took it back to their headquarters and put it into a tank.
"If a fish is eating, it's healthy and it's happily now munching it's way through the algae on the side of that tank."
But Mr Ellis appealed to people not to discard unwanted, foreign species into UK waterways.
"Obviously someone decided they didn't want it and put it in the canal, but that's not the right thing to do as there's lots of issues there, especially around bacteria and parasites," he added.