Question Re: Oto placement   12/10/06
Hi Tom,
<<Hey, Sean.>>
I have another question for you already.
<<Let's hear it...>>
I was at a major chain pet store today, and much to my surprise, they were selling Otos (Otocinclus) for $1.99. Since this is the first time I've seen them in my area, and that price is too good to pass up, I bought 3 (I read on WWM that they do well in groups). I have 2 tanks, and I can't decide which one they would do best in.
<<The quarantine tank, Sean. (Being a little silly but I’ll explain.) The store I buy my fish from, my Otos included, is, literally, a “Mom and Pop” operation and won’t sell their freshwater animals for the first two weeks after they take delivery, i.e. they quarantine them all. Saltwater fish are held for four weeks with cards posted on the tanks showing the dates that the fish arrived at the store. That said, I can guarantee that this isn’t the case with your Otos. Point number one. Next, Otos are notorious for being difficult to acclimate. Wonderful little guys that they are, they’re easily lost early on no doubt due to the stress of transporting, handling, lack of sufficient food and – the big one – means of capture. Because of their tiny size and naturally tangled environment, many (most?) of the Otos that reach the store have been taken in the wild using cyanide, or other chemicals, to disable them for collection. (I would be skeptical that ‘tank-raised’ Otos would be going for $1.99 each. Mine were $3.99 each which I thought was a bargain.) The upshot here is that these chemicals can remain in the internal organs of the fish either shortening their natural lifespans of about five years or leading to a much, much earlier demise. Darned hard on the Oto, to be sure, but if one is lost and picked at by another fish, it, too, may end up with contamination from the chemicals I referred to. Now, let’s move on to your options.>>
Tank one is a 24g tall/show tank, moderately planted, with a cheap "fizz tab" CO2 system. Its inhabitants are 4 Opaline Gouramis, Trichogaster trichopterus (2 are the gold variety), 2 paradise fish, Macropodus opercularis, 2 Ramshorn snails, and one common Pleco, who will be re-homed soon as this tank will be way too small for him (he's only about 4" right now).
<<Sounds like a good choice, Sean. And, I appreciate your thinking regarding the upgrade for the Pleco.>>
Tank 2 is a 5g, moderately planted, with no CO2. Its inhabitants are 1 Betta and 3 cherry shrimp.
<<Could be a good option as well but, personally, I like to add some aquarium salt in with my Betta. Your Otos would “tolerate” the amount of salt I use but I don’t think they’d appreciate it very much.>>
Both tanks have laterite and gravel substrate, a good amount of driftwood, and a pH just above 7. Neither tank has much of an algae problem, although both tanks have small amounts of green "spot" algae.
Now, here's my question: which of these tanks would be a better fit for my Otos?
<<As you may have gathered, Sean, I like the larger tank for your new pets. The smaller tank would likely work just fine but I’m not a huge fan of keeping Bettas with other fish. Just me, perhaps. Also, if you do decide to add salt to your Betta’s tank down the road, and I do recommend this, it probably wouldn’t sit well with the Otos if they were in the tank.>>
Sean
<<Enjoy your new fish, Sean. Tom>>

What do I do with extra Otocinclus?  5/30/07
I have a 5 gal. Eclipse Corner Tank on my desk at work. There were 2 Betta's (with a divider) in it, but when I added 3 Oto's from PetSmart soon after the Betta's died of tail/fin rot. I moved them to separate bowls, and treated them but they died. I figured it was the addition of the Oto's so I expected them to die as well. That didn't happen. They cleaned my tank of all algae, and I feared they would have nothing to eat because it seems they won't eat the algae flakes. So, I went to my buddy's Cichlid tank and traded all the ornaments (no, I don't know if this was a smart thing to do or not, but I did it anyway). It seemed, that this brought new life to the Oto's, as very soon after I spotted little white things on the front of the tank. When I realized it was fry, I shut off the filter. I counted about 12 fry stuck the glass. I turned to the internet for advice and found little. I put a baby sock rubber banded over the filter intake and turned that back on. Added an air pump for them. I fed them boiled spinach leaves. Well, a spinach leaf from a coworkers salad stuffed in a cup of hot water. They ate little holes in that overnight. I do a 50% water change weekly, and slowly suck out the leftover food every few days to keep the substrate somewhat clean. Now I keep exchanging plants with my buddy's Cichlid tank for food and they clean it overnight. There are now 4 or 5 baby's left and they are half the size of the adults and seem to be doing fine. My question is, what can I do with these extra Oto's? Can they go in the Cichlid tank? Isn't that too much hardness for a Cichlid? Or can I support 7 to 8 Oto's in a 5 gal tank? PetSmart told me that they stock the same sex in the same tank and sell them that way so this wouldn't happen. Well they screwed up and now I have these new guy's. What do people do with their new fish when they didn't mean or even know they would spawn?
<Wow. This is quite an amazing tale! On the one hand, a 5 gallon tank is really too small for Otocinclus. As a group, Otocinclus are considered "delicate" because they need good water quality and lots of oxygen. In most community tanks, they tend to be short lived. But yours are doing well, so well done! Anyway, as to where to put the Otocinclus. I personally wouldn't mix them with anything other than, perhaps, South American or West African dwarf cichlids. The problems are multiple. Firstly, yes, they will not do well in Lake Malawi/Lake Tanganyika type aquaria. Such hard and alkaline water conditions will not suit them at all. Secondly, when kept with slow moving things like angelfish and discus they tend to suck the sides of the bigger fish, scraping off the mucous. I've seen this in my own tanks, with the Otocinclus rasping away on large gobies, creating nasty blisters. Aggressive fish like convict cichlids will simply hammer them to death. So ideally, give them to someone with a peaceful community of other small fish such as barbs and tetras. PetSmart cannot possibly sex Otocinclus so their advice there was nonsense. In fact, breeding Otocinclus is quite uncommon, so you've actually done rather well.>
Tom
<Cheers, Neale>