Oto sudden death

[Dazydaizee]

Looking for some help on Otos that died very suddenly...

I was very reluctant to buy fish from the pet store after such bad experiences in the past and such great experiences this time around having obtained all from independent sources. But I couldn't find Otocinclus anywhere but 2 pet shops, one of which was awful. So when I found them at Petsmart in good condition tonight, I went ahead and got some. They had nice plump bellies, were active, no signs of disease or illness save one with a little tear in the tail.
I got a total of 18 Otos and 6 cories. The Otos were to be split between 3 tanks (46 gal, 36 gal, 10 gal), 6 in each. One of the tanks is at work, so I was separating out the cories & 6 otos to bring with me tomorrow.

Admittedly, I did a quick and probably useless acclimation which I realize now was a mistake, but having had such great luck (and not a single death) with quickly acclimating fish & inverts right out of a box after 2 days in the mail... I just didn't think much of a 10 minute trip from the pet shop...
What I did was float the bags, move 6 Otos to a dip 'n pour container, add in about 25% (probably less) water from the 36 to the container. Added another 25% or so about 15 minutes later, then dumped them in about 10-15 minutes after. For the others I had little water left to work with to separate them so I ended up putting about 50% from the 10 right into the bag. I then separated them out and after about 15 minutes released 6 Otos into the 10 gallon, and the other 6 along with the cories into a large container that was seated in the 10 gallon so that I can easily transport them tomorrow.
All seemed well.

I looked into the 36 after 20-30 minutes of adding the Otos and 1 was laying dead. I removed that one (probably the largest and plumpest). I went back to the tank a minute later to throw in some zucchini and found another dead in some moss at the top. As I took that one out I saw a third swimming very erratically up and down and turning over, clearly in distress. I immediately scooped a jar of water from the 10 gallon where all Otos were alive and calm (and water parameters are normally identical), scooped the fish out and placed it in the jar. It paused a bit, then continued odd swimming behavior, but more slowly, and died within 30 seconds. I started searching for the other three, found one that seemed perfectly fine. I scooped it out and put it in the 10 gallon. I set up tests for the 36 hoping that everything was still normal as it had been a day or two ago when I last tested (I did test the 10 directly before and ammonia, nitrate, & nitrite were 0 and pH about 7.4.) While the tests for the 36 were running I saw the other 2 Otos who seemed perfectly fine. Tests were Ammonia & Nitrite 0, Nitrate 5ppm, pH about 7.6. Temp in both tanks is 79-80.
10 gallon has only some snails and a couple baby dwarf crays (shrimplet size) and just a dual sponge filter (I'd been planning to take the tank down but then found the baby crays, so it needs some work). There are plenty of plants and driftwood in both tanks. The 36 has snails, khuli loaches, bristlenose pleco, a few male endlers, & RCS. It has a Rena Filstar canister filter, a dual sponge filter, and a large airstone.

Any ideas? Is it just a coincidence that the 3 fish who died were all in the same tank, or is there something I'm missing?? I feel awful and I'm worried about the rest of them even though they all seem just fine (as do the cories). I don't even want to go look in the tanks now...

Thanks...

 

[Kaosu]

ottos are sensitive when you first get them...if your going to lose them it will be with in the first few weeks (if you can keep them alive that long you should be in the clear)
these little fish are almost alll wild caught, ..they sedate them, shipping is hard on them and loss is very high.

when buying them wait untill they have been in the tank for a few weeks..pick out the ones without rounded or rubbed off tail fins, you might not of done anything wrong, these little fish are roughly handled and like i said loss is high when transporting...youtube has some videos on how these guys are captured in the 1000's by adding a paralytic to the water up stream to top them from getting away.

keep an eye on the rest and see how they do.

when getting them from large pet stores ask when there shipments come in...come in the day they get them and look over the tank...then wait and come back the day before the next shipment..those fish ( should be your best bet, it sounds kinda mean but the week in the petstore kinda kull out the sick fish that will most likely die at home anyway.

this is just my experience i did allot of research on these little guys, before buying, and this is what has worked for me i have 3 and have yet to lose one in a year ^_^.

hope this helps.

 

[wrek]

Where the bellies simply plump or were they VERY large? If they're really large it could be a bacteria. Everything else looks fine. I'd take them back and exchange them but maybe look for some without huge bellies? -- Though it doesn't make sense, unless it was the stress in the move from the store that they'd die quickly after being introduced into your tank if it was bacterial.

-- What day of the week did you buy them and what day of the week does your petsmart get it's fish stock in? Mine gets theirs on Thursdays. I shop there Thursday night so the fish have calmed down a bit before I buy them, but I've made friends with one of the guys that receives them so he'll hold onto something if I'm looking for it. Ideally, I'd like to let them stew over night and get them on Friday. I like them to get calmed down but not sitting in the tanks there too long.
Anyway, I ask because it's possible you bought them too quickly after they were put in the tanks?


I have several, from Petsmart. No issues and I did far less acclimating than you.

 

[Dazydaizee]

Their bellies looked plump in a healthy way.. like my bristlenose plecos, not disproportionately large. The larger one may have been a bit questionable, I guess.. but the others all look like a good, healthy weight.

On the shipping topic... I've heard about buying the older stock from pet shops for healthier fish, but I've also read that one of the biggest reasons Otos die is starvation and that they often come in to the stores thin and then are not fed properly and continue to lose condition. So once I saw those nice, healthy looking bellies and nice active fish, I guess I jumped at the opportunity. For some reason until you mentioned this, I didn't even make this connection.. but the staff was sorting a box of bettas while I was there.. so now I wonder if this was shipment day and they may have just been added to the tank today. I guess that makes sense since I don't usually see so many of them there.. normally when I do go there, I'm there early on Mondays and they're usually unpacking fish. Well, that was stupid of me not to realize....

 

[wrek]

I guess buying them fresh or waiting for them to age at the pet store is a debatable topic. Some fish I'd say yes, wait.. but there are some fish that won't last a day in the tanks at the store, not because they die but because they sell out. Black Ghost Knifes for example. They're gone quickly.

 

[Kaosu]

not stupid... youv only lost 3...keep an eye on them and you should be fine.

 

[Dazydaizee]

It's been awful... 15 dead fish in 3 days. As luck would have it, that leaves one in each tank (remember I started with 6 per tank divided over 3 tanks). At least now I know it's not the tank... or the tank setup, inhabitants, filtration, etc.. because while the water quality is great in all three, the setups vary quite a bit. So I've got a bag of dead fish in the freezer and I'm not holding out for the other three (They look fine, but so did the other 15). I should know by tomorrow if they stand a chance.. since it's been a daily thing..

Funny thing is that all 6 cories are doing fantastic, nice and active, settling in well. All of my other fish are great... including the 30 shrimp I received who sat in a box in the mail in the nice New England winter for 2 days and arrived alive and well, and the 30 snails who spent one day longer in the mail and were completely unphased and munching on algae wafers immediately.
Never again with Otos.. but just to be sure I've learned my lesson, I'm guessing ONE will survive to a ripe old age so I'll feel guilty about not keeping adequate numbers...

 

[Khemul]

Sometimes waiting isn't a good option. Around my area they are somewhat rare (not hard to get, just that stores generally don't like ordering them in unless they already have the demand) so they don't stay very long in the store tanks.


The main theory I've heard on Oto death is that the sedation used to catch them may damage their kidneys and/or liver. It seems to depend on how hardy the fish were when harvested, but most of the causes of sudden Oto death seem to be linked to internal problems/organ failures that are blamed on the sedatives.

 

[RustyRay]

I killed my first batch of Oto's in exactly the same way, by doing a quick acclimation. But ever since then, I've kept them successfully by using the drip method.

It think as aquarists we have a built in belief that we should get the fish out of the bag as quickly as possible. I think that belief is all wrong. Fish are great at surviving long term in poor water conditions. But they're not so good as dealing with sudden changes in water chemistry.

I'm a broken record -- but we should acclimate fish slowly, even if the fish have been shipped a long distance and have been sitting in a bag for days, or if they've come from a local store, which is 10 minutes away.

I set up a slow drip (30 drips per minute) and let them sit in a small bucket for several hours, sometimes overnight. I haven't lost a fish yet with the drip method.

 

[Dazydaizee]

I haven't lost a fish yet with the drip method.

I don't doubt that a very slow acclimation process would have helped, yet it does nothing to quell my guilt and frustration over purchasing these fish in the first place. I just feel bad for them and I do wish that I could ensure every animal in my tank was born in captivity vs. wild caught just to die in a cage in my home. Then again, I know the issues with raising animals captively on a mass scale as well.
I thought I'd looked into otos enough prior to their purchase, but apparently I hadn't. I am hoping to at least stick to animals who thrive in aquaria.. I never again want to witness so many die due to the stresses or adverse reactions to drugs used in their capture.
The remaining 3 were alive when I last saw them today, so I'm hoping when I get back tomorrow night they'll still be okay...