Otos dropping left and right

[eco23]

Hi everyone

I started with 7 Otos in my 46 gallon during a diatom outbreak back in March. To my surprise, all 7 of them survived and seemed to be absolutely thriving up until a couple weeks ago.

First I randomly found one dead in a plant being munched on by a shrimp. It was one of the skinnier ones, and I chalked it up to an isolated incident. A few days later I found another in a similar situation. Over the last 2 weeks at least 5 of the 7 have met the rose garden including 2 of the nice fat ones.

Now I know Otos don't have a good survival rate and are sensitive, but the fact they're all dying off together obviously says there's a common cause. Also since they've been in the tank together for 6 months it compounds the mystery. Water parameters are pristine...0 ammo, 0 no2, 10 no3, pH 7.4. Stocked with Danios, Red Eye and Neon Tetras, a Bolivian Ram, Amanos, RCS and Panda Corys

Here's the only changes recently-
*Added 6 Panda Corys about a month ago
*Began conservatively dosing Flourish comp 2x per week
*Fighting off algae with a blackout and pwc's a few times per week

I'm also dealing with an algae issue I seem to be getting a handle on...and on the DW it's possible there is a bit of Cyano (I'm not good with algae ID's). It doesn't appear like the pics I've seen of Blue/Green algae, but for a period the tank had an "earthy" smell which led me to that conclusion. I've heard some strains of Cyano release toxic compounds and I wonder if that is related, yet it's only effected the Otos.

I've heavily stepped up my pwc routine since the deaths to fight the algae, and obviously cleanse the tank if something is polluting the water causing the deaths.

So....is it possible the new Corys are outcompeting the Otos for food? (I'd think they have different diets). If it is indeed an outbreak of Cyano algae (technically bacteria)...might that be related? I have to assume the new ferts wouldn't be involved.

Thanks for any ideas.

 

[librarygirl]

Aw sorry about your fish Eco! This is out of the realm of my experience but just wanted to say sorry about your fish and I hope you find the cause.

 

[eco23]

Aw sorry about your fish Eco! This is out of the realm of my experience but just wanted to say sorry about your fish and I hope you find the cause.

Thanks. I really liked the little guys even though they're the smallest fish in the tank. The Corys kinda stole their thunder with all their activity, but I've always been especially fond of the Otos (and thankful for the way they took care of the diatoms for me). I've lost other fish and buried them, but the fish that I truly was upset about was my GBR and my Otos. . Hopefully someone has an idea.

 

[Deckape]

Thanks. I really liked the little guys even though they're the smallest fish in the tank. The Corys kinda stole their thunder with all their activity, but I've always been especially fond of the Otos (and thankful for the way they took care of the diatoms for me). I've lost other fish and buried them, but the fish that I truly was upset about was my GBR and my Otos. . Hopefully someone has an idea.

No ideas but you know I hate that for you.

 

[User]

How well were they eating? Was algea thier only food supply? Mine eats a lot of algea but does not touch any processed food. I feel as though 7 might be a lot and you cutting down on the algea may have cut off food supply for all seven. The two larger ones may have died due to all the water changes. I know I lost a few when I did numerous water changes to cut down some of my nitrates. When I stopped, they stopped dying...and now I only have one happy (?) one..

Maybe an isolated event, just my personal experience...
I hope you find a reason as well and sorry for your loss. I loved my ottos as well.

 

[jcolon]

Sorry to hear about your ottos Eco... Hope your other fish continue to do well!

 

[eco23]

How well were they eating? Was algea thier only food supply? Mine eats a lot of algea but does not touch any processed food. I feel as though 7 might be a lot and you cutting down on the algea may have cut off food supply for all seven. The two larger ones may have died due to all the water changes. I know I lost a few when I did numerous water changes to cut down some of my nitrates. When I stopped, they stopped dying...and now I only have one happy (?) one..

Maybe an isolated event, just my personal experience...
I hope you find a reason as well and sorry for your loss. I loved my ottos as well.

Thanks. They would occasionally munch on an a wafer during the night, but they seemed to rely on bio-film and algae. There's still plenty of algae in the tank, but the diatoms they loved are long gone (and have been for months...thankfully...and due to them).

Honestly I can't blame water changes, I've always been OCD with my tanks, and doing 2-3 pwc's a week (although not necessary) has often been part of my routine. I'm a big believer in fresh, dechlorinated, temp matched water = happy fish.

At this point I'm really leaning towards Blue/Green algae toxicity (which I've seen mentioned, but not explained)...or simply being outcompeted for food that I didn't know they relied so heavily on. They're deaths really did start occurring shortly after the introduction of the Corys. Their behavior also changed after the Corys were added. They used to be very active and chase each other around the tank, but since the Corys...they became much more fond of hiding in the DW.

I appreciate everyone's responses

 

[User]

Np just throwing my idea out there! Maybe the cories brought something with them? Though I doubt it since you probably qt and whatnot.

Good luck finding out! I think you may be right with the algea thing then!

 

[librarygirl]

Doing a bit of research.....many people have had trouble keeping Ottos. Apparently to catch them in the wild they use cyanide and other toxins to stun them which then kills them at some point in the future. Did you buy all of the Ottos at the same time and/or from the same source? Not sure if this was the reason, but could be a factor.

They also apparently have a certain gut bacteria that can deteriorate if they don't have the proper nutrients to maintain it; so during transport, at the LFS etc if they are starved the anaerobic bacteria die-off so when they are introduced into a tank with algae they simply can't digest it.

Of course take all of this with a grain of salt; it's just what I've found doing some quick searches; nothing I'd feel secure in citing as a source. If I can get some time at work I can go through some of the databases and see if I can find documented info.

This is a bummer though b/c I had wanted to get Ottos for my tank eventually. Oh well.

 

[absolutangel04]

I personally have doubt about the cyanide thing, though I have heard it too. When you buy fish, you can always ask if they were wild caught or tank bred. I try to keep only tank bred fish when possible, but my kuhlis were wild caught.
Anyway, it is possible that the issue may be the type of algae in there. I would try supplementing blanched vegges for the ones still in there. They should have a decently plump tummy when viewed from the side. I have removed my skinny ones from the community and given them veggie supplements and that has helped them to stay healthy. You can try temporarily removing any skinny ones and giving them some extra tlc in a qt tank or something (if available). That is the best advice I have at the moment. I am very sorry about your little guys. I hope the ones you still have stay healthy.

 

[eco23]

Doing a bit of research.....many people have had trouble keeping Ottos. Apparently to catch them in the wild they use cyanide and other toxins to stun them which then kills them at some point in the future. Did you buy all of the Ottos at the same time and/or from the same source? Not sure if this was the reason, but could be a factor.

They also apparently have a certain gut bacteria that can deteriorate if they don't have the proper nutrients to maintain it; so during transport, at the LFS etc if they are starved the anaerobic bacteria die-off so when they are introduced into a tank with algae they simply can't digest it.

Of course take all of this with a grain of salt; it's just what I've found doing some quick searches; nothing I'd feel secure in citing as a source. If I can get some time at work I can go through some of the databases and see if I can find documented info.

This is a bummer though b/c I had wanted to get Ottos for my tank eventually. Oh well.

You really are a librarian, haha!

Thanks for the info, I'd never heard any of that other than the cyanide thing which I'm not certain is always true. Check out this video...it's crazy -
Collecting Otocinclus affinis in their natural habitat - YouTube

Don't let this scare you off of Otos. They're awesome little fish. I had mine for about 6 months and truly enjoyed them. I may go get more eventually, but I hate to QT them for weeks in a new tank without established algae. A lot of them don't take to algae wafers or veggies...and if they didn't they'd basically starve to death. Something I'll have to think about.

Thanks for the info

 

[ilostnemo]

ph is what i say. personally ive had ottos do that in around that ph. lower it and you should be safer. ive kept one for 2 years with a ph of around 6.6

 

[ilostnemo]

ottos are only wild caught

 

[eco23]

ph is what i say. personally ive had ottos do that in around that ph. lower it and you should be safer. ive kept one for 2 years with a ph of around 6.6

Thanks. Thing is all 7 have been in that pH together for around 6 months. I'd find it hard to believe that would be the time frame where they couldn't take it any longer and died off together...maybe if it had happened randomly over time, but 5 within 2 weeks seems a little off for me. I guess anything is possible though.

 

[absolutangel04]

ottos are only wild caught

There are tank-bred ones too. I have tank-bred otos.They are certainly less common, but they are out there.

 

[ilostnemo]

how did you get tank bred otos? and eco they can do that, ive had otos in a tank with 7.5 ph and the 6.6 at the same time bought the same day. the ones in the 6.6 lived a little over 2 years the 7.5 i kept for about 7 months then they died.

 

[eco23]

There are tank-bred ones too. I have tank-bred otos.They are certainly less common, but they are out there.

I was just gonna say someone posted a thread not long ago with baby Otos that showed up in their tank (maybe you?) A guy who works at a LFS near me used to breed them too. I agree they're rare...but not exclusively wild caught. I think the whole cyanide thing is a myth in many cases too (as shown in the video), though nothing would surprise me. It seems the entire Internet is convinced they're stunned with toxins...but apparently not all.

 

[ilostnemo]

eco. i also love how you joined a year after me and slaughter me in posts. lol

 

[eco23]

... and eco they can do that, ive had otos in a tank with 7.5 ph and the 6.6 at the same time bought the same day. the ones in the 6.6 lived a little over 2 years the 7.5 i kept for about 7 months then they died.

Huh. I guess anything is possible...it's just weird to me they'd all have the same expiration date after all this time.

 

[eco23]

eco. i also love how you joined a year after me and slaughter me in posts. lol

I don't even pay attention to post count in 99% of cases.

I guess the high post count is what happens when you put together a guide and are expected to chime in on every fishless cycling thread. The home office helps too, haha