Loaches Online Forum

Yesterday, I ran into the next round of hillstream trouble: two Vanmanenia's dead.

Unlike everything so far, these deaths do not make sense. Namely:
1. Not new fish, I had them for five months.
2. The tank is in good condition, lots of air, current, heavy plants.
3. Water parameters are perfect (0/0/<10/6.6)
4. No changes to the tank in two months.
5. No other fish (6 hillstreams only, now 4).
6. I do take precautions against contamination from other tanks.
7. No symptoms/signs before/after death.
8. Filter/powerhead are fish-safe.
9. Fish was totally fine 30 hours before I found the bodies -- this was the last time every one was looked at carefully.
10. The only new food tried was the Carnivoir pellets (but they are eaten by schisturas and Beaufortias without any problems.)

Basically, nothing to go on whatsoever.

Now, my wife's reaction was "old age" (she is not an expert, but saw this fish a lot.) Jim's comment was the same (Jim -- thank you! -- is obviously the top expert, but did not see the fish). I can add to it that half the fish I originally chose was the largest and I did notice that on two the pattern on their sides was faded (probably an old age sign). But I cannot accept old age causing *two* deaths at once, something else may be wrong.

("Old age" is only possible as follows: one fish died first, the other ate it and died from the toxins created by decomposition....this is what I assume happened, but I cannot rely on this.)

One comment on "old age": statistically, someone who keeps 60 hillstream loaches with 5 year lifespan should expect an old age death about once a month. I think some of you do have this many and can confirm or deny this. (BTW, this is absolutely horrible, now that I've realized it..) On my end, I have about 30, but some are schisturas and I don't know their lifespan (?)...not enough statistics.

One thing that greatly bothers me is that all unexplained hillstream deaths I had are Vanmanenia's (I do have other species). Unfortunately, it is not something anyone else seems to keep, so I even don't know for a fact if it is possible to keep them long-term, but I have to assume that I might be mistreating them. Either environment or food are wrong.

(Incidentally, the store they came from had very difficult time keeping them alive. I know some mistakes they made, but despite their efforts they could not keep any alive for more than 2 months. Schisturas, Gastros, Beaufortias -- no such problems.)

It is my responsibility to try to make it work, but I have no idea what to do now.

For now, I did a large water change, put in the quarantine drugs to cover the possibility of an infection, what next?

Some crazy thoughts now:

Some Vanmanenia's are Brackish. .. maybe I should add trace amounts of sea salt?
Maybe they need live food? (but they seem to be more vegetarian).
?????

Ideas are welcome.

TIA

Oh, and one specific question to people who keep hillstreams...

Do you see any clustering of unexplained deaths of particular species? If yes, what are they?

"Unexplained death" === a death of a fish you had for more than 2 months where you have no idea of the cause.

I think I see such clustering on Vanmanenia...googling around on Confuzona seems to indicate such a clustering there as well (but I maybe wrong--I don't have Confuzona's).

Thanks for the "top expert" compliment, but I don't know about that.
I learned a tremendous amount from a certain guy who posts regularly on this site by the name of Martin Thoene.

I have had unexplained hillstream deaths. In fact, most hillstream deaths seem to be that way. Usually, when hillstreams die, they seem to just burn out. You might notice a change of color (usually faded) a day or so before and maybe reduced appetite, but that is often it. I have even had them eat in the morning and die in the afternoon. No other fish in the tank died or were ill at the same time or later.
You have no idea what your fish went through prior to finding their way to your tank and no idea how old they are. Perhaps, as the fish got older, its immune system weakened allowing some normally harmless bacteria to kill the fish. Perhaps the other fish could have eaten it and developed an infection too.
I say "Perhaps" because I just can't say for sure.
You have to remember that we are still "writing the book" (no not THAT book;) ) on hillstreams and learning more all the time.
In your case, you are one of the few around here who has had this species so you are in uncharted waters.
Before you go adding salt or making changes , perhaps, you should just observe for a few days and see if you have any more deaths.
Adding salt or making other changes when your parameters seem fine may create another problem that you might falsely attribute to the death of the other fish.
So, my advice is to just chill for a few days and observe the fish. You have had them now for a bit and should be able to determine if they are behaving abnormally.
Good luck!!!

(1stly apologies to Martin --- I did not mean what I apparently said. I learned/learning a lot from him too...)

(2ndly, to assure: I'm not making any random changes until I have reasons to think they will do good rather than harm.)

I also don't think I can do anything instant. It is some kind of long-term effect.

I cannot learn anything by observing: they seem to behave normally right now. The only unusual thing was that the food was not fully eaten yesterday -- but this is probably because they ate a dead one. They did finish the food today.

The current plan is to quarantine them further, checkups every eight hours, and -- probably in two weeks -- move them to the community tank where I have one more Vantanmenia. That one was around for seven months, is certainly a young one (much larger now than originally)....maybe somehow that other tank is better.


Darn. I really hate when I have nothing to go on. It is so much nicer to deal with ich, skinny disease or septecimia.

Donno what I'm going to do about the hillstreams. Maybe I should just stick to the species you two proved to be "keepable".... lots of effort went into these Vanmanenia's, including frequent checkups no other fish here gets. All for nothing.

I would definately not say this is all for nothing.
First of all, you may not have anymore problems with these fish.
Secondly, as I said, you are in uncharted waters and anything that can be learned about these fish is important.

So far, I'm learning awfully little...in fact I'm only learning that there is a problem, and I don't think I'm out of the woods at all.

I now have five losses and five alive (one is in another tank and came from another source -- may be significant).

Losses:
1 after 1 day -- clearly shipping related.
1 after 1 week -- very likely shipping related.
1 after 2 months -- cause undetermined.
2 after 5 months -- cause undetermined.
Something wrong here.

In contrast, with Schistura I have no losses yet (1 year), and with Beaufortia (almost 6 mo) I have one due to a known cause (that sucker-killing bacteria). With Chenis, I have a truly horrible record, but every single loss is accounted for (and all occurred within the 1st two months). This looks like an anomaly of unknown nature.

The only other time I saw an anomaly like this was with B.Kubotai's. Turned out that they have a high tapeworm infection rate and being sold smaller, succumb faster....easy to fix, once you know what is wrong. This one is a puzzle.

UPDATE. No more problems so far. Of the remaining four, three seem young, so hopefully no dying in the immediate future.

I've been discussing this elsewhere, and someone (who is a known experienced fishkeeper) thinks that the problem was O2 deprivation caused by rotten excess food in a small tank.

He said, in particular:

CFC on TFF wrote:Could excess food have been left uneaten over night and removed oxygen from the water as it started to break down? Balitorid loaches are very susceptible to low oxygen levels and the weakest of the group would have been affected. This is even more likely if the tank has live plants as during the hours of darkness they switch from using CO2 to O2 so an increase in O2 demand from uneaten food could take the levels over the edge.

A possible scenario is like this:

One dies from the old age, I don't see the body for possibly as long as 24 hours (it was in a place where it was hard to see), body decomposes together with extra food, O2 deprivation kills one more fish; followup cleanup and water changes presumably stopped the process.

Does this make sense?
(The tank in question does have good O2 sources: lowered water level with a HOB filter + a powerhead....so it is very difficult for me to imagine running out of O2).

That's possible, particularly if its a small tank. There's that whole BOD (biological oxygen demand) situation. Dead fish+excess =increased BOD. Whether that is enough to kill old or weakened fish, I don't know.

Very interesting, thank you.

IME, this species is definitely weaker than an "average hillstream".

OK, I guess I have to try to adjust the procedures to cut the chances of this happening again. Don't fully understand how, yet.

I think I'm going to cut on food in all hillstream tanks, this had to be one of the contirubuting factors. I wonder if one other way I messed up was by not having any dither fish in the tank at all (wanted them to have nice undisturbed life and possibly you-know-what)...3-4 WCMM's would ensure that there is no leftover food.