Barb tank melt down...

[Magnum Man]

I'm not sure what happened, but the mascara barbs paid the price... I could only find one last night... all the smaller fish seem to be alright... the mascaras were the medium sized fish, and everything has always been peaceful in that tank... my best guess, the torpedo went berserk??? it's grown into a 10 inch heavy bodied fish... but last night, it appeared normal, and hanging with the Tin Foils... I suppose another possibility is the mascaras ( 3 ) 2 males and 1 female, reached sexual maturity, and the males had a brawl??? I haven't been home much over last weekend, so not a lot of observation... they are all bigger fish, so capable of some banging around... not much hard scape in the tank, to maximize the swimming space, a resin hollow log on each end, intended to give the smaller fish some shelter, and a handful of 1 inch sticks standing in a corner, for the pleco, and to add some wood component to the water, but otherwise no line of sight breaks in this tank, which hadn't needed any previously??? last night I couldn't find 4 - 4-5 inch fish, with not many hiding places for a fish that size, I suspect the worst open top tank, with lots of Pothos on the long sides... if someone were forced out of the tank, they would have had to have gone over the hang on tank filters on the ends... didn't see any fish on the floor, but the lights on that tank had begun to dim, by the time I checked on it, and noticed this last night...

 

[GaryE]

That's unfortunate. They looked really cool.

I'm going to sound like the old teacher I am, so I apologize in advance. But it's been my experience that if you have a crowded tank, as you like to have, the weakest link crashes. Often, the most expensive and most beautiful link crashes. Any aggression or imbalance is amplified by crowding. It doesn't matter how good or how skilled you are.

Unless you see it go down, or a fish turns into a serial killer, it generally remains a mystery.

You need more tanks!

 

[Magnum Man]

yes... unfamiliar fish in a crowd... I know nothing about the torpedo... and not much about the mascaras, but assumed they would not have the cichlid breeding charictoristics

 

[Magnum Man]

lights aren't fully on yet, but the smaller long fin Rosie's are all fine, and no fin nipping... the spot tail algae eaters all fine, as are the long fin core's and the long fin green dragon pleco.. Only one of the 3 aspera's is swimming around ( smaller than the mascaras ) I want to blame the torpedo barb, but would think there would be fin damage on the smaller fish... I did just add a few large almond leaves, so maybe the big leaves floating around freaked out the bigger fish, and started a chain reaction, or added to the water, where the mascara males fired up???

 

[GaryE]

So, devil's advocate here.
What makes you suspect aggression?

I expect if that were the case, the smaller barb would have died first. The corpses would have showed wounds, as would other fish. An aggressor fish may target one fish, but not three without going for five, or ten as well.

Why couldn't it be stress related disease, maybe something dormant in the Dawkinsia that was activated by stress?

Long finned rosy barbs are a longtime hobby favourite, mutations of a species popular for 75 years because of extreme hardiness. They would survive rough company and stress, though if the torpedo barbs were the culprit, those long fins would be lunch. Dawkinsia are the new kid in the hobby, beautiful barbs that have only recently become readily available, although still "high end" in the trade. They're reputed to be more delicate than the old "Puntius" group.

I used to really like barbs (still do), and kept a lot of them (alas, no more, just 2 species). When Asian barbs were killers, it was a war of attrition, and the wear and tear showed before it moved to fatalities.

 

[Magnum Man]

in early morning light, I didn't find any dead, or damaged... ( just missing completely ) and they were always in plain sight... there hasn't been any changes to that tank for the last 3 months, and everyone appeared to be thriving... I'm still on my previous minimal water change routine, until the bigger RO fires up this week... so nothing that wasn't there last week / month, with exception of 3 large dried Indian Almond leaves...

knowing little about the residents ( except the Tin Foils ), and almost no previous keeping experience ( except the Tin Foils, that have been here around 3 years )

do the male Dawkinsia get territorial, or excessively rambunctious, at sexual maturity??? it they started flying around the tank, & got the 4 larger fish bouncing around, it could have resulted in a violent reaction??? little if any damage initially noted, just missing fish, & just the mid sized fish...

 

[GaryE]

I've never kept them - they came into the hobby after I went for smaller tanks than they need. So I don't know how rowdy they get.

I have seen similar die offs with other species though. Fish look great for months, or a year, and then all die the same night while tankmates are unaffected. I've at least twice lost entire species in divided groups, in different tanks, within a 3 day span. Tankmates were unaffected.

It's weird as it gets, but I figure that Mycobacter isn't the only infection that lies dormant in fish for a very long time, and can explode out when things aren't right for the fish. Deciding what was wrong in the set up is hard when it's a recent addition to the hobby like that. There's not a lot of info.