A debate over otos and green algae--oto owners, pls give your opinions

LeahK

LeahK

AC Members
Jul 5, 2007
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I have always trusted the info I get at wetwebmedia.com. Those folks are really great. However, they say that otos eat fuzzy green algae exclusively, which contradicts many people here at AC who say that their otos live off brown algae and green spot algae.

So, I'd like to kinda open up a discussion here over the following quotes from wetwebmedia:

"What Otocinclus need is green algae (not diatoms and not hair algae)." (http://www.wetwebmedia.com/FWSubWebIndex/otosysf.htm)

"Otocinclus really don't eat anything much besides green algae and the microorganisms therein. Brown algae, blue-green algae, etc. aren't substitutes! To get green algae growing, you'll need 2 Watts of light per gallon, at least. There needs to be a 'turf' of green fuzzy algae on the plants and rocks. THAT'S what these little catfish eat." (http://wetwebmedia.com/FWSubWebIndex/otofdgf.htm)

"The problem is that they feed on really only a single thing -- aufwuchs, a combination of green (and exclusively green!) algae together with the tiny invertebrates that live within that green algae 'biofilm'. Unless you have an established aquarium of large size with very strong lighting (2+ watts per gallon) so that green algae can flourish, it is exceedingly unlikely your Otocinclus will be getting enough to eat." (http://www.wetwebmedia.com/FWSubWebIndex/otobehf.htm)

This raises so many questions for me. What is the green algae "aufwuchs" they're mentioning, that is neither green spot algae nor green hair algae?
Are my own otos nutritionally malnourished, because they live off diatoms? (I do give veggies, but they seem to ignore them.) I've had my guys since May, and they seem fine. In fact, they are gigantic. :)

I'll be really interested to hear what other oto keepers think about the above quotes.
 
I can speak from personal experience. I have otos and a tank full of algae. The only algae they consumed was green spot and diatoms, ignoring green hair, black brush algae, blue green algae, and various unidentified green slimey algaes.
 
Mine eat both brown and green spot, ignore supplemental algae wafers completely, and can't seem to decide whether they like zucchini or not...sometimes I catch them sucking on it, other times it's removed untouched. Haven't tried any other veggies yet. I have 2.1 wpg and have only noted 4 types of algae in my tank since starting it up: green spot, brown, staghorn, and BBA...of which I've already mentioned I see my otos munching on the first two quite often, never touched the other two. I've never seen growth like the fuzzy green algae described in that article. Judging by the very full round tummies, nice dark coloration, very active schooling behavior, and significant growth since I purchased them, I have a hard time believing my fish are malnourished. I do agree that they need to go into a mature tank since they're so sensitive to sudden shifts in parameters and some never make the diet shift to supplemental wafers and veggies. But I don't agree with their view that they'll only eat one form of algae. Most of these guys are wild caught, and I doubt there's only one algea type that grows in isolation that they feed on in the Amazon, and if they were so specialized as to eat only that one form, we'd all have to be importing Amazonian algae to have any success at all in keeping them alive. Just my thoughts...
 
ditto what they said, and NEVER use algae no more in a tank with otos
 
I believe that the aufwuchs that is referred to is the biofilm that grows in our tanks that normally you don't see readily:
The plants and animals adhering to parts of rooted aquatic plants and other open surfaces, also organisms and detritus coating rocks and plants and the glass in an aquatic environment often fed on by fish specialized as scrapers.
Here is a picture of it while trying to get a close up of one of my sids in my 55G. My otos eat this, brown diatoms they devour, and occasionally I'll catch one of them trying to get a bite of algae wafers that I feed the cories. Nothing eats true green spot algae, it's too hard. I have less than 2 WPG in all my tanks with otos and this aufwuchs grows. But like I said, you can't really see it unless you put magnifiers on!

IMG_3665.jpg IMG_3669.jpg
 
I agree with Debbi, aufwuchs are the microscopic life that grow in established tanks. "Bioslime", if you will, are complex groups of lifeforms including bacteria, algae & animals etc.
It's not the only food otos eat of course. But since they are (virtually) all wild caught aufwuchs can be an important food until they & their owner can find what they will eat in captivity. Not all otos will eat the same foods, mine like shrimp or earthworm pellets occasionally but being nocturnal I can't be sure what else they might try.

My otos never have made a significant dent in green algae or diatoms nor have I seen them eat either. Maybe they're spoiled for food choices, they look fat & sassy, when I see them.
 
Thanks for all the comments (and the photos, Debbi). This makes me feel much better, because my experience with my otos seems to be the same as everyone who has replied so far. Mine rarely touch supplemental food, yet they are very fat, and from what I can tell the only algae in my tank is brown and green spot.

Because of what I read at wetwebmedia, I had been trying to grow green algae outside in a plastic bin, algae which I snitched from a koi pond. But it is extremely scary looking in that bin right now, and I was dreading the idea of putting any of that green slime in my tank. So, based on what I'm reading here, I think I'll skip it. :)
 
My otos only ate brown diatom algae and softer green algae, they can't scrape the hard green stuff off the sides of the tanks...
 
Mine don't eat hair or spot algae either.

A suggestion that may help increase aufwuchs in your tank: use oak leaf litter (like for shrimp and some invertebrates). My otos nibble on the leaves as they decay. To prepare them, just soak them in water until they sink, then add to the tank.

:) Sounds like your otos are doing great, but you could always try other foods. Mine adjusted really quickly to eating the Omega Sea veggie rounds, so you could see if the brand makes a difference. Have you tried slightly cooked carrots? That was the first vegetable mine ate.
 
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