Most potential parasites of native fishes do no reproduce well in the confines of a tank. There are always exceptions but in 45 years of fish keeping parasites that were not already established on the fish have not been a problem. There are some potential parasites that use crustaceans as hosts and can be problem but I've never experienced them yet.
I have seen some tanks over run with thread worms and isopods but for the most part it was poor tank husbandry that caused the problem. These types parasites are relatively easy to get rid of.
All wild caught fish have the potential to have worm type parasites that cause problems, healthy fish in the wild generally carry a parasite load through out their entire lives with minimal health effects, most of these parasites need an intermediate host like a bird to be able to reproduce.
Some fish are more vulnerable than others, I have been told that bowfin are very susceptible to these internal parasites and bowfin carry a huge parasite load in the wild.
Much like salt water reef tanks freshwater has it's own invertebrates that many people mistake for parasites but they are often helpful to the ecology of the tank. Scuds, flat worms, tubefex worms, even some aquatic earth worms and lots of tiny creatures that often live quite well in tanks with large fish because the large fish do not eat them the way small fish will.
Hydra are pretty cool in a freshwater tank, i feed lots of live daphnia and hydra often come in on wood and rocks i collect from streams. i like to add a piece of wood or rock directly from the pond or stream so I get these small creatures. Much like the idea of live rock in marine aquariums the creatures are generally helpful and not a real problem.
BTW if you are lucky you might get hydra that have algae inside they live off of similar to coral, freshwater sponges also occur that have algae they grow inside themselves.
I have seen some tanks over run with thread worms and isopods but for the most part it was poor tank husbandry that caused the problem. These types parasites are relatively easy to get rid of.
All wild caught fish have the potential to have worm type parasites that cause problems, healthy fish in the wild generally carry a parasite load through out their entire lives with minimal health effects, most of these parasites need an intermediate host like a bird to be able to reproduce.
Some fish are more vulnerable than others, I have been told that bowfin are very susceptible to these internal parasites and bowfin carry a huge parasite load in the wild.
Much like salt water reef tanks freshwater has it's own invertebrates that many people mistake for parasites but they are often helpful to the ecology of the tank. Scuds, flat worms, tubefex worms, even some aquatic earth worms and lots of tiny creatures that often live quite well in tanks with large fish because the large fish do not eat them the way small fish will.
Hydra are pretty cool in a freshwater tank, i feed lots of live daphnia and hydra often come in on wood and rocks i collect from streams. i like to add a piece of wood or rock directly from the pond or stream so I get these small creatures. Much like the idea of live rock in marine aquariums the creatures are generally helpful and not a real problem.
BTW if you are lucky you might get hydra that have algae inside they live off of similar to coral, freshwater sponges also occur that have algae they grow inside themselves.
