All right, first things first. Otos like to be kept in groups. You could probably get 3-4 more for your tank....HOWEVER you need to do something about that ammonia level first. Otos are VERY sensitive to initial tank conditions. They are very stressed when you get them from the pet store and I've heard mortality numbers of up to 50%. Once they settle into your tank for a while, though, they can tolerate some occasional "harsh" conditions.....they toughen up a bit. They also appreciate a planted tank and hiding spaces. Also, how long have you had your tank set up? If it's a new tank and uncycled (which might be why you have ammonia) you need to wait for the cycle to finish before introducing any more fish, let alone otos.
a. How do your Otos behave during the day?
My otos hide during the day, mostly. If they are out feeding, they are very skittish and quickly hide when people walk by the tank. From what I've observed, they mostly feed at night.
b. Have you ever observed your Otos with the lights off? How do they behave?
They mostly just "flit" from surface to surface in the tank, looking for algae to eat. When they find a good patch, they munch on it for a while and then move on.
c. When they look and behave like the following, I can assume they are doing ok:
A fat oto is a healthy oto. Look for a little round belly and a tail that tapers nicely up to the mid-section (basically, the tail should be as thick as the belly where the two meet). If the tail is very skinny, your oto isn't eating or there isn't enough food for him........that's a problem.
d. When they look and behave like the folllwing, I have reason to think they are not doing well:
See above. Also, if they are pale in color it's never a good sign.
e. How much food do you feed them, how often?
Otos don't really eat flake food. They eat algae, for the most part. So, you shouldn't really have to feed them. However, if you don't have enough algae in your tank, you can supplement them with some blanched spinach, cucumber or zucchini. Leave a piece in overnight and see if he eats it. You'll probably be able to see little pieces of oto poop on it if he was eating. It tends to look green-ish in color. I never really had to feed mine but I imagine you'd want to do that every other couple of days if there isn't any algae in your tank. Never leave the vegetable piece in the tank for longer than that overnight period. It could foul your water. Otherwise, they should be able to make do with the micro algae that grows on most plants/decorations. I haven't really had any success feeding mine algae tabs. They just don't seem to go for them.
f. Have you ever seen an Oto not actively feeding for a day or so?
I rarely see mine to begin with. I thought that my original 10 had died down to 3 at one point. Then, I did a major tank overhaul and found that I had 8 otos left (at least).
g. Have you ever thought you found an Oto dead, but it started moving again later?
Due to their size I imagine that otos are potential prey for any number of fish. This is probably the reason for their behavior patterns. Mine used to swim to wherever they were going and then land and stay still. After making sure the coast was clear, they'd start feeding for a bit and then stop again. Like I said, they're a little skittish. I doubt it's uncommon for them to spend a lot of time just sitting still, hoping that no one sees them.
I've also seen them fall on their backs while sleeping. Very funny. On occasion, while gripping and inclined surface, one of my otos would just kind of "fall" backwards. The first time I saw this I thought something was wrong and tapped the glass to see if it was still alive. It snapped up and righted itself in the same spot it had been resting before and acted like nothing happened. Very odd.
h. If you had an Oto that during the middle of the day, was laying on the gravel so still you thought it was dead, but it wasn't, what would your course of action be?
Well, if it looks fine overall (like as described in c) I leave it alone.......maybe tap the glass to make sure it's still alive. If it looks sick in any way, there's really not much you can do.
From what I've read, the way they catch otos is by stunning them with chemicals in the water. This does some level of damage to their organs. The ones that survive are held and shipped in containers lacking the algae they need for their diet. So, by the time they arrive in the pet store, many of them are sick and starving. If they can bounce back, they usually do, given that the water parameters are normal. If they are too damaged from their ordeal, then there's really no treatment that will help them.
I would just continue to do water changes and find out why you have ammonia in your water. If your tank is uncyled, keep up on water changes to keep the ammonia at or as close to 0ppm as possible. If you have an established tank, there has to be something wrong with what you're doing to be causing an ammonia spike. Find the problem, fix it, and cross your fingers. BUT DON'T INTRODUCE ANY MORE OTOS UNTIL YOU DO!
Good luck!
