Most likely it's just a matter of time before another fish gets zapped. I found a baby at an
LFS many years ago, and dropped it into a 55 community tank of African cichlids, thinking it was too small to do any harm. The next day one fish was dead, one was dying, and a third was never quite right afterwards. I gave the finger-length catfish to a friend with 1 125 containing 3 adult oscars and a dinner plate-size pacu. One oscar spotted the new, feeder-size fish and moved in for a snack. It got within 1-2 inches, then turned back suddenly. It tried once more, same result, the second oscar only tried once, the third not at all. The pacu seemed afraid of the little bugger from the start. A couple days later I saw the tank again. Wherever the little catfish was, the 4 huge fish were as far away as they could get, and maintained max distance at all times. It was funny to see such large fish so terrified of a little squirt.
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