Mysterious post-spawning disease

["Maladorno, Dionigi" <DIONIGI.MALADORNO@roche.com>]

Hello! I am new to the list, and I was planning to lurk for a while.
However, the following topic is too interesting (I am currently quite
focused on diseases in Discus) to sit and watch! Apologies if I write
something I shouldn't have written! So, here are some comments and
questions:

Tom Mroz and others wrote about their problems with a mysterious disease
affecting mainly male Apistos, shortly after spawning. The key symptoms
seem to be breathing difficulties, followed by bloating and death. 
The way I see it the most puzzling part of the story is the preferred
male target, which somewhat makes infective and water quality causes
less plausible (but not totally impossible). Why would, say, a fluke, a
bacterium or an improper osmotic balance affect males only? Gender
differences in response to various forms of stress or disease certainly
may exist, but the extent of the difference (males bloat and die,
females are perfectly normal) is really intriguing. So, I think it would
be helpful to know the following details about individual post-spawn
bloat episodes from the people that experienced this problem :

- - water source and conditions (pH, dGH, dKH, assuming that ammonia and
nitrites were OK)
- - any recent introduction of new fish in the tank
- - gender/species/age
- - previous medications given
- - was the affected fish moved to another tank after spawning
- - sequence of onset of the symptoms and time they lasted
- - medications given after the problem occurred
- - were other fish in the tank affected
- - outcome (fish dead/survived)

If detailed information is available on several cases, it may be
possible to get some hint helpful to confirm it and maybe in the future
find an explanation. 

Again, I hope this kind of post is in line with the tone of the list.
Nice talking to you guys!



Dionigi Maladorno
dionigi.maladorno@roche.com
This message presents personal opinions which are not necessarily those
of my employer.