So sorry to hear about your longfin...I'll be watching this thread too! Must have names for the lil' buggers. Watch the thin tatty one turn out to be the biggest bruiser, lol.
Things sure can happen quick, though. You adding any greenery to your setup?
Greenery + Oscar = green salad
Does the Lemon have red eyes? . . .or is that just the camera?
Considering that you have had the majority of them for 6 weeks now, I wouldn't expect to be seeing sunken stomachs. It looks to me like you have some form of IP's in that tank, some fish worse for wear than others. If you can get NLS Hex-Shield in your part of AU I would highly recommend feeding that to clear your fish out. If you can't get your hands on any Hex Shield I would recommend checking out my sticky on the 3% epsom salt solution. If one fish has it, the parasites will get spread about via their feces, so you will want to treat all.
Last time i heard it still not available in Aus but will definitely ask tomorrowNot sure if this will help, but Paul Talbot at Majestic Aquariums in Sydney is the AU distributor.
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