The fish previously mentioned did unfortunately die. He just never ate and ignored all the food we gave him.

My question does concern two of the other Bolivians that we got (we purchased 4 all at once). 1 of them looks very thin (since we got him) but he eats well and "plays well" with the other bolivians. We are worried, since we lost a bolivian that was also thin to a parasite. Does this sound like something similar? He is still a young Bolivian, and we want to be careful about treatment if he needs any. Is this a common issue among Bolivians??
As for the other young bolivian, he has started doing something very strange...every once in a while he "twitches"...his body bends toward one side or the other...like this:
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If that makes any sense...it doesn't look like an "itch" as he makes no attempt to rub up against anything and I've never seen him rubbing on anything. He doesn't twitch all the time, it usually just happens 2-3 times in a row and then he continues swimming. IT also seems that nothing in particular triggers him to "twitch" ... it just happens pretty randomly. I have no idea what this could be. Any ideas

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Thanks always!!!