I am familiar with these trematode larvae, they are mostly harmless to fish, but a disease cause to the bird it is eaten by, and only activated when that bird that eats the fish. I have had a couple wild caught fish show up where they were visually obvious.
And the disease cycle was part of my microbiological studies many years ago.
There are a number of protozoan species that use this snail to fish to bird life cycle from the northern east coast of the U.S. thru South America.
The cycle starts with a snail, that is eaten by a fish, and continues when the fish is eaten by a bird.
If the fish is not eaten, the life cycle stalls (the fish is simply an in-between carrier with inert trematodes).
In aquaculture, if the parasites build up in a closed system, then it can overwhelm the fish, but wild fish seldom pick up enough trematoads to become overwhelmed
In ordering this species, because it comes from a very specific black water, rheophyllic South American habitat, unless your water parameters exactly match that natural habitat, or you can artificially match it in your tank with powerheads, and by adding tannins, that would be (to me) the more pressing concern.
