No one knows your fish and your tanks better than you. If you've spent any amount of time observing your cichlids, you'll soon know what behavior to expect when you approach their tank, feed them, perform water changes, and various other tasks in which you interact with them. For this reason, you'll usually know something is wrong before you actually spot the problem.
It happened to me tonight. While feeding my 55g mbuna tank, one of the three red zebras was not making an appearance. Usually the most vigorous eaters in the tank, not seeing one within a minute or two gave me that "oh no" feeling. I finished feeding the tank and sat down to watch. After about 5 minutes, I knew something was really wrong.
Because the tank contains numerous holey rock and river rock from end to end, I naturally began moving stuff around attempting to get "eyes on" all three zebras simultaneously. I moved about 85% of the rock and still never saw more than two.
The next step was to start removing the rock. While doing so, I thought I saw some detritus that moved funny. Then I saw them. Yep, FRY!
Okay, so that might explain part of the problem. The fry had to belong to one of the zebras because I did notice one of the zebras really getting after the other cichlids in the tank while they were all feeding, which was unusual. I was not able to sex the zebras when I bought them because they were only about 2" TL and I hadn't given it any more thought. Thus, I really wasn't sure if I had a breeding pair or not.
As I pulled the third large piece of holey rock from tank and almost had it in the bucket, I heard that unmistakable fluttering sound of a fish's shake. I turned the rock over and, sure enough, one of the zebras was lodged in a hole. It was pretty pale compared to the others, so I can only surmise it might have been in there for a while.
I successfully dislodged the zebra once I had the rock back in the tank, but it was swimming very slowly and gingerly. It was still pretty pale after a minute or two.
Though the largest of the three zebras, my conclusion is that this was the subdominant male who was beaten up pretty badly and simply ended up in the hole. Either that, or it was driven there and had become stuck. The former hypothesis makes the most sense, though it happened pretty quickly. Less than 24 hours prior, all three zebras were actively swimming and eating.
About 10 minutes after extracting the zebra from the hole, I noticed it lying sideways on the sand at the back of the tank. I thought it had expired so I brushed its tail with my finger. It righted itself and slowly swam under a rock. I don't have a quarantine/hospital tank set up and can't get one set up until at least tomorrow. I suspect it will be too late by then but I will check on it in the morning and see if it survived the night.
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