In my 46 planted I can't ever find all 6 of my otos. I typically can find 4. I just tried yesterday. It is worrying me as well.
However I figure they must be alive until I see a carcass. One previously died which I replaced, and he/she was a floater so easy to spot. I hope Otos have a tendency to float when dead because I dont want to tear through all my aquascaping to try to find them.
Some hide in my slate caves upside down, some on the glass, some on the plants.
Ya, I usually find remains of fish that die, whether floating, on the bottom or stuck on the outside of the filter intake. All I know is my Spotted Raphael looked fatter on Sunday. Maybe it's growing orrr.................
Since I started this thread the original missing Oto has not shown up yet. My sons tank was showing some algae so I picked up 4 Oto's yesterday. He took the larger 3 and I took the smallest one. After acclimating for almost 2 hours I release the new Oto into the tank. I turned on the lights and found it cruising up and down the glass eating. I sat and tried to account for all the fish in the tank and now one of my original 2 Oto's is missing!! What is going on? Something mysterious going on here..........
Mine are tricky to spot as well. They are excellent at hiding. What tipped me off to one of mine dying was a nitrate spike that was out of the ordinary. Just keep an eye on things, but more than likely it's found an excellent hiding spot. Mine are easier to count at night if I keep a room light on when the tank light is off.
Sometimes I try and count my remaining fish in the tank but fact is it is designed to mimic a natural habitat and often the fish find better hiding spots than I realized. For instance I have 4 krib which I have only seen 3 of for weeks. Last week the 4th decided to come out at feeding time to my surprise as I expected her to be a carcass hidden under a plant. It was a relief and also cool that the ecosystem I have built is self sustaining and vibrant regardless of my involvement at this point.
Well, no bodies last night. I will check water params, but I am constantly at 0 for ammonia and nitrites and around 10-20 for nitrates. My 2 inch Spotted Raphael catfish wouldnt have an appetite for them?? He's the only one with a big enough mouth to try and eat one.