Just because a fish outwardly looks very healthy does not mean it is a carrier of pathogens and internal parasites that can get introduced into new water. A fish can be a tolerant but carrier of internal problems. Moving wild fish can be done but it is pretty risky. Be prepared for eventual latent problems that can show up a few years later as the community becomes mature and maybe over crowded fish exposed to "stress problem". Lots of times tiny thin almost clear fish leaches attach to fish fins and are never noticed. Internal tape worms are always a continual problem in wild fish who are constantly exposed to everything in that wild ecosystem. There are salt dips and soaks that can minimize transfer of external stuff; not internal digestive tract stuff of protozoans and parasites.
As an example here is a list of the number of differnt parasites of smallmouth bass over their distribution in the USA.
protozoans 12, trematodes 49, cestodes a2, nematodes 13 acanthocephalans 9, leeches 9, mollusks 1, crustaceans 9. The most common ones are bass tapeworm, black-spot and yellow grub. The bass tapeworm will cause sterility or limit SMB reproduction.
Last edited by Bill Cody; 02/26/20 05:27 PM.
