parasites from stream gravel?

[blueether]

Back history:

until about 4 or 5 weeks ago all my natives were outside and in cramped conditions and possably poor water conditions - not enough w/c's. When they were moved back in to their 430l tank some of the bullies ad fins that were in a poorer state, a bit torn etc but no sign of infection. I added a little salt (about 2-3g/l) for the first week, that was removed with about 30% weekly w/c. in the first few days of the tank being re-setup the ammonia peaked at about .25 but came down quite fast. In the first week the feeding was light to help with any ammonia spikes.

At about 2 week in I noticed that one of the big torries was breathing hard and was listless but still looked to be eating. Increased surface agitation. didn't seem to help.

At about 2 1/2 -3 weeks the torrie passed on

At about 3 weeks I noticed the same in one of the big female Cran's bullies, within 24h she was dead as well.

At about 3 or 4 weeks I saw one or two bullies with raised spots on tails or pectoral fins, started with more salt (3g/l)

By 5 weeks (now) the spots have got large, maybe 5+ bullies have developed them, and in the first two fish that I saw the spots on some spots have vanished. some bullies are flashing.

I have done 2 50% water changes in the last week and the salt is now at 4g/l. Yesterday I thought I was perhaps on top of the infection as I hadn't seen new spots for a day or two.

Tonight I see that one bully has new spots and for the first time I see what could be a spot on a kokopu. until now only the bullies have shown spots. Most of thes spots have been where there could have been fin damage from when they were outside - I've not seen spots on their main body until tonight with the kokopu and one bully.

The bully has a spot/growth on in in it's gill plate.

The spots are very raised and much bigger than ich, almost growth like but look to be somewhat embedded ie on one of the bullies tail the spots were visible from both sides.

The only thing that has changed in the tank is moving all the fish back inside and the addition of stream gravel. The gravel cane from a flood course from a clear-water stream. Where it came from was water filled with a very slow flow, maybe about 1 1/2 feet deep and quite warm. there were bullies and a trout fingerling in the pool where it came from. The gravel was only rinsed in the same water, not under tap water.

I'm wondering what the parasite/infection could be, and if I should up the salt some more (adding another 400g atm to take it to about 5g/l)

Photos:

And on or in gill cover:

[Stella]

mm, I have seen those bumps before in my fish, but not sure what it is. Usually appears when the fish have had low-level stress for a long time,usually summer heat.

I think salt worked on it (I would recommend cranking it up to 6ppt and maintaining that for at least a few weeks), and improved water maintenance. It does take a long time for those bumps to go away completely.

The deaths seem odd. Maybe there is something else happening that caused that and lead to the bumps secondarily.

[Sophia]

can you use fenbendazole on these fish? that's the stuff a few of us used on some odd white internal worms that were visible from the outside of the fish, and made their way to the outside.

also I wonder, could you do an autopsy to see if it's a worm or something else?

[blueether]

Thanks for the idea sophia, I'll see how a bit more salt and time goes.

Stella, I'll admit that the water when they were outside was neglected, as is so easy to do when it isn't in the same room as you.

I'll bump the salt upto 6ppt a bit latter - they have already had one increase tonight.

[blueether]

Ok... three weeks of salt at 6ppt with ~40% w/c every 5 or so days with no deaths, then 2 within 2 days. Didn't notice the first one acting odd at all but the second one was lethargic on fri. night so did a w/c on saturday and found 1/2 a bully. within an hour of the w/c the one that was listless was all but dead slight tear in the tail but otherwise looked ok...

in the last three weeks there has also been 3 spawns. 2 Cran's and a common.