quarantine question...

[Magnum Man]

so, most of us??? at least in the past, I have built my tanks, around the fish first, then tried to add "environment"
I know when I was raising Tilapia, the seller warned about snails carrying disease... i could never keep the bladder snails out of the tanks, growing the fish outside...

but that makes me question adding non fish livestock, to an existing tank... is it likely micro crustations, shrimp, and or dwarf crayfish, or snails, could cause fish death, in a mature tank??? it's not likely we could quarantine copods, or other little critters that are good for our tanks, and provide food for our fish... I'm at the point that I'm adding these beneficial lil critters to my tanks... I know they likely should have been added before the fish, but hindsight is 20/20...

 

[Magnum Man]

adding this, non fish related... I remember as a kid, I had a grass hopper in a jar, one day it started pooping out this white thread... I assume now, that it was thread worm, but it was like almost a foot long, that came out of a medium sized regular grass hopper... so, it's likely any wild foods could contain nastiness we don't want in our fish...

 

[GaryE]

There are a few parasites that a tank could have, but it's an enclosed body of water and they're hard to miss. What's more serious, and I have no data to prove this observation, is viruses and bacterial pathogens in the fish already there. This has only been a problem for me when I introduced wild sourced fish to tanks with farmed fish. I've always assumed that the blackwater fish I like encounter less bacterial life and fewer viruses in their extreme environments. Farmed, aquacultured fish are exposed to many more diseases than wilds, due to crowding, mixing of fish from different regions and forced growth techniques. It's a first contact scenario.

Your Tilapia are food fish, and there the stakes are different. Outdoor fish around here can contact blackspot, a harmless to us bird parasite that uses the fish as a carrier. It ruins their commercial value, as it's ugggggly. Even easily treated Ich makes fish inedible, as the trace meds shouldn't be ingested.
When I used to keep native fish, red bellied dace, pearl dace and other minnows from pristine environments often had black blotches.

I've used live food from forests for many years, and have yet to see any signs of parasites or diseases from them. I pick my spots and go with clean water. I like snow fed, fishless habitats - vernal pools. They dry up seasonally, but by then I'm culturing what I caught in the backyard, out behind the garage...