Unknown Archer Death

[Fella]

I recently added 3 archers to a freshwater tank.

This morning (7 days after having them) I found one of them dead.

The night before they were all feeding happily (spitting all over the place).

I cloned the filter from a freshwater one, and midweek raised the SG to 1.005. Water comes back as 10 nitrates, ammonia and nitrite 0.

The other fish are fine, and displayed no aggression to the other fish (I have never seen them squabble, nor would i really expect them to in under a week).

The fish that died has showed no symptoms of illness whatsoever.

So now unfortunately I'm left with 2 archers (I believe to be microlepis). Will they fight? I'm assuming it's quite likely. They're quite small, only 4-ish inches in length. Not exceptionally young (they spit quite far, and did not need to be taught) and I'm concerned that they may squablle as they get older.


So my questions are -

What is likely to have caused the death?

Are the 2 remainders likely to squabble? (I thought I was risking it with 3 as it was...)

Are they notriously fragile?

Are there any precautions I should now take?

 

[flamingonhot]

Well, this is all I can think of at the moment but..

Did you raise the Sg all the way up to 1.005 in one day? IMHO, you should only raise it by .001-.002 per -week-. If that's the case, they might have gotten a shock from it.


lmao sorry if I misread that..i'm sitting here trying to think of what could have gone wrong..and I just turn up a blank .

 

[Dave Legacy]

Did you raise the Sg all the way up to 1.005 in one day? IMHO, you should only raise it by .001-.002 per -week-. If that's the case, they might have gotten a shock from it.

I doubt that increase in salinity killed the fish because archers can adjust to salinity changes quite quickly. The biological filter on the other hand, cannot. Rasing your specific gravity that quickly could screw up your cycle and cause a spike. Archers aren't friendly dudes, they will establish a pecking order, but I haven't seen aggression so bad that someone was killed.

Archers are hardy fish, at least T. jaculatrix. I don't tell this story often, but when I first established my archer tank I was impacient and used bio-spira which bombed miserably probably because of a light salt content. I experienced a huge spike of ammonia at 8.0ppm for three days straight, archers almost completely black with silver spots showing signs of extreme stress. The only thing that saved them was 50% water changes every 4-5 hours for a week (middle of the night, middle of the day, had to be done), and then daily for a following week. The fact is that the NH3 and N02 was always present to some degree for 2 weeks... my friends swear they're invincible.

Unless you can come up with some firm evidence to narrow down it's death, it might have just been a fluke thing, or maybe it was diseased before you got it. Maybe it was overly stressed when captured or in transit. Maybe it was captured with the use of toxins, not nets. Keep a close eye on the other guys for a couple weeks and see what happens.

Sorry for your loss.

 

[nmonks]

In my experience, raising from 1.000 to 1.005 should have little to no effect on the filter bacteria. It's only once you get past 1.005 that the bacteria start to "change" to the high-end brackish/marine ones. So assuming your nitrites are still good, I'd dismiss SG change as the key factor.

What is likely to have caused the death?

Difficult to know. I'd suggest two things. Firstly, there could be aggression between the fish you haven't seen. Archers (and monos) dropping off one at a time is fairly common. There may be a stress issue going on that makes the bullied fish weaker in some way. Second possibility is damage/sickness since being collected. Either way, for now, I wouldn't worry too much.

Are the 2 remainders likely to squabble? (I thought I was risking it with 3 as it was...)

Yes. Keep an eye on things. If you're lucky they will establish a hierarchy quickly and that will be that. Since these fish are from a fairly small species, they may be able to settle their differences within the confines of an aquarium better than the larger species. But my personal experience is that archers sooner or later end up as single specimens.

Are they notriously fragile?

No; archers are quite tough. So basically I'd agree with Dave L. and say you were unlucky and leave it at that.

Are there any precautions I should now take?

Beyond trying to pin down exactly which species they are, there isn't much you can do. You might want to think of a backup plan in case the two archers do fight, though.

Cheers,

Neale

 

[Fella]

Thanks for the replies.

The steps I think I'll take from here will simply be to watch the new guys, hope they don't fight, and be on the look out for more of the same species, to dissipate the aggression.

Thanks for the replies!