Losing mature common bristlenose

[ali12345]

1. Water parameters
a) Temperature range. - 25 C
b) pH. 7.3
c) GH. 12
d) KH 6
e)Ammonia 0 , Nitrate 40 , Nitrite 0
f) Water change frequency
twice weekly 10-15% each time
(Most LFS's will check your water and give a list of readings).

2. Tank set up
a) Size. 2700 litres
b) Substrate. sand
c) Filtration. 4 fx5
d) Furnishings. bogwood, ornaments
e) Other tank mates. filament barbs, clown loaches, synodontis, scissortails, L066, L340 , clown plecs, banjo cat, midnight cats, cories, porthole cats, rainbow cichlids
f) How long has it been set-up? At least a year, probably 2 years
g) When was the last new fish added? 3 months L66
h) Foods used and frequency? twice daily, flake am, catfish pellets, courgette, frozen bloodworm, live river shrimp - harvested from other tank.

3. Symptoms / Problem description
No symptoms until they turn up dead but after losing a couple of 8 years plus bn females I have now lost more of them and am now losing males. Lost both of my alpha males.
Younger fish seem fine. I have had several bloodlines in there over the years.
No other fish are affected.
No changes to the tank at all.
I have new fish in other tanks but so far as I know I have not cross contaminated and bn seem fine.

4. Action taken (if any)
Tested water as above.
Large water changes - hma water. Taken out some of the furniture so bodies more easily found.

5. Medications used (if any)
none


Ideas anyone ? Inbreeding issues. Can't see how anything would be so specific to particular fish. Lost my second alpha male yesterday - he had the best branching bristles, really complex - just like a mature stag.

Alison

[.Plecomania.]

everything looks fine in what you listed, maybe just overfeeding or random aggression from other catfish, though BN males can hold their ground.

[JamesFish]

Hi,

Is it possible the L66 you added last have been growing fast and now out size the bristlenoses? (Assuming they were = or smaller to start with?) Its just a thought that they might be hounding them out of hiding places / territory and pushing off food.

It could be a very wrong guess but as the last change unless something else just got big enough to hurt them or stress them.

[ali12345]

The L66 are still smaller than the bns.
Although thinking about it all - I did move in a male bn from a different tank. He isn't the biggest but commandeered his own cave.
Can one bn terrorize a whole colony?