I've always heard that even if fish were never stocked in an isolated pond, eventually some species would show up there. Supposedly fish eggs would stick to the legs of birds wading in another pond, and when the birds came to the first pond the fish eggs would come off, grow into adult fish, and eventually start reproducing.

Is there any truth to that, or is it an old-wives tale? (Or an urban legend, to use the modern term.)

A friend of mine is putting in a pond and has talked to several biologist about getting the pond stocked. Both of the biologists told him that even if he didnt put any catfish in the pond..(he wants to raise/catch bass) he will have catfish due to the "eggs on legs" fact.......

Fisheries Biologist told our fly club that all though it is possible that eggs and legs might happen it is more likely that during flood conditions small fish and fry will move upstream even through very shallow water. It is even more likely that some well meaning person put the fish in there.

The theory is true. My friend has a pond on his property and every summer the pond dries up, although in the early spring there are small catfish and bass in the lake. Unbelievable....believe it.