Who values the "Otos?" We all should.

As I find myself spending a lot of time writing descriptions of fishes for our upcoming debut of "Tannin Live!", I'm reminded of just why I fell in love with certain fishes, question why I never liked others, and find myself becoming an "advocate" of sorts for fishes that I feel are either under-appreciated or underrepresented by the majority of hobbyists.

Nowhere do I feel the need to be an "advocate" more than when looking at my favorite small catfishes, specifically the lovable, popular, but seemingly mis-perceived as "disposable", Otocinculus species!  These are comical, endearing fish that are both misunderstood and shockingly disrespected, in my opinion.

It's a shame that, for whatever reason over the years, we've tended to heap a lot of small. bottom-dwelling fishes as "scavengers" or assigned them the ridiculous moniker of "cleanup crew" or "janitors" or whatever, somehow simultaneously devaluing the fish and relegating them to an arbitrary "role" in our tanks that is both underserved and quite frankly, often inappropriate.

Now, I suppose that the popular term "catfish" to the hobby at large over the decades probably instantly brought to mind a picture of a non-descript "bottom-feeding scavenger fish", patiently sifting through the substrate for uneaten food or algae; going about its business as members of it's group had done for eons, blissfully unaware that this was the only shot at sustenance they would get.

Nobody was going out of their way to target feed the "scavengers", right?


Now, wait a minute....This is a catfish, right?:

Oh, and so is THIS:

Sure, fishes like the Otocinculus are about as good a consumer of algal films as "they" make- but to purchase the fish solely for this role not only "commoditizes" the fish- it feeds the perception that its sole "purpose" is to "clean the tank." I'll say it one more time: These small, seemingly non-descript fish are actually quite fascinating and engaging, and worthy of much more attention and respect than merely being regarded as "cleanup crew" by hobbyists.  They are remarkably "social" fish, with interesting interactions and group dynamics that are enjoyable and fascinating to watch.

That is, if we're not solely adding them to our tanks for the purpose of cleaning up the mess.

In the wild, they are found in large aggregations in streams and rivers among submerged and floating vegetation, and are well-adapted for life among plants and submerged tree roots and driftwood.

These aggregations should tell you something about their personalities, right? Remarkably, when offered for sale in the aquarium trade, many unsuspecting neophyte hobbyists are advised to purchase "one or two" as cheap "algae eaters" for their new tank. And of course, being small, gregarious, social creatures, they can be very shy when kept singly, yet display surpsingly interesting social behaviors when kept in groups of 6 or more. And that, by the way, is exactly why we offer them in groups at Tannin Live!

It just makes sense to us.

Interestingly, their dietary preference creates a strange sort of "paradox" for many hobbyists who treat them simply as humble "algae eaters", placed in a tank for the sole purpose of consuming unwanted algal films (which they do an amazing job at, BTW): They are so good at consuming algae that, in an aquarium without sufficient algal growth, a population of these fishes could literally "eat themselves to death" by consuming all of the available natural food resource rapidly. This is why it's important 1) not to keep too many in a small tank  and 2) to understand that they can and will consume other foods, like frozen brine shrimp, etc., and 3) to make sure that food is made available to them.

Because of their shy, retiring nature, when you supplement their natural algae diet, you need to make sure that food reaches them, and that the other tank inhabitants don't beat them to the food. It may take a little more time, but these endearing little fishes certainly are worthy of the attention!

It's an extra act of kindness that is most definitely not misspent, in my opinion. Now, "shy and retiring" typically applies to them when they're new. They will often become far more comfortable and be out in the open much more when they've adapted to their new home. And, since they really are found in groups in nature, we feel that keeping a small group of them in the aquarium helps to "socialize" them more quickly.

As stated above, "Otos" are really interesting fishes in and of themselves, and should, in our opinion, be treated like any other fish in the aquarium. That is, you should accommodate their need for food by never adding them to an "immature" aquarium that doesn't have some algal growth present, and making sure that they get their fair share of prepared, aquarist-fed food as well. And obtaining food is really the main battle these fishes face, and the by-product of poor handling along the chain of custody from capture to aquarist leads to weakened fish with a poor survival record, further reinforcing the negative perception that they are somehow "expendable" creatures...

Mike Tuccinardi, who curates and handles our fishes for Tannin Live!, will be the first to tell you that these fishes suffer from that horrible "commoditization" which tends to overtake many small, bottom-dwelling fishes in the hobby. To that end, he suggests that we all consider the challenges the fish face on the way to us, and understand the extra steps that we are taking to assure that they remain healthy before they get to you:

"...it just takes a little TLC along the supply chain to keep these interesting and useful little fish happy and healthy. The primary issue with this fish is access to food – as mentioned earlier they tend to arrive half-starved and weak, which usually traces back to the conditions they were held in immediately after collection.

Sadly, some Otocinclus in the trade may not be fed between that point and the time they reach a store (which can be a week or more), so they are in far from ideal condition on arrival. Our supplier actually holds these fish in earth ponds until just before they are scheduled to ship out – which provides them with a low-stress environment and plentiful natural food (algae). The difference is immediately noticeable on arrival: strong, healthy fish with nice full bellies. I make sure to keep them that way by providing food as soon as they leave the bags and right up until they ship out to you."

With a little bit more of an understanding- and a lot more attention paid to their needs- I think it's entirely realistic to create a fascinating and engaging aquarium for the sole purpose of featuring and enjoying this fish! Could you imagine an aquarium set up to represent the streams from which they come, complete with some smooth, algal film-covered rocks and pieces of driftwood, and perhaps a few aquatic plants? And a group of several dozen Otocinculus in the mix? Yeah, the potential for learning more about-and perhaps even breeding- these shockingly misunderstood, yet remarkably endearing fish is amazing!

We really need to re-think our "relationship" with these little fishes.

Like so many things in our hobby, it involves a "mindset shift", a re-allignment of our perceptions, and a greater appreciation for the needs and challenges of the amazing animals that we treasure so much. So please- the next time you're thinking about purchasing one or more of these fishes for the sole purpose of being "algae eaters" in your high-concept planted aquarium, consider their needs...and if you aren't convinced that this is worthwhile, I'd implore you to consider honing your algae-scraping skills instead, and leaving these little guys to the care of someone who appreciates them for more than just "utility."

Tough love. Yes.

Okay, I'm off of my "soapbox"...Well, for now anyways! 

Stay diligent. Stay compassionate. Stay educated. Stay enthusiastic.

And Stay Wet.


Scott Fellman

Tannin Aquatics 


Scott Fellman
Scott Fellman


2 Responses

Scott Fellman
Scott Fellman

December 07, 2017

I agree! Once they settle in, they are as hardy as any other fish. I was very happy to see that so many in our community value these fishes as much as we do. In fact, a bunch were talking about creating a tank with a large group of these fish as the exclusive residents! Yeah :)


Frank Maccarrone
Frank Maccarrone

December 06, 2017

Ottos are one of my favorites also.I haven’t bred them yet, but I keep trying.They are very tough little guys when they have adjusted to the aquarium after a few months. FM

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