Update Sept 27, 2018.
I stand corrected - post #4 here
https://www.monsterfishkeepers.com/...om-dayton-oh-in-mar-2016.699701/#post-7885560
I'll just quote my post in its entirety:
"All 4 paroon shark catfish have been doing well. Grew some but nothing to write home about. The biggest is probably close to 3', another is in between 3' and 2.5', and the last two are ~2.5'.
Mostly peaceful except for an occasional surprising bout of chasing and biting each other. It has lessened tremendously since the beginning year or year and a half but has not disappeared. I attribute this to hierarchy disputes and enforcement. It has lessened enough for all of them to grow back their pretty extensions on all fins.
Also a bit surprisingly, they are yet to take a marine or freshwater frozen fish for me. They only take exclusively pellets. (But see below.) Perhaps this also contributes to slow growth, albeit they don't look thin but rather well fed.
They don't seem to interact with their tank mates. Or so I thought for these 2.5 years since getting them in Mar 2016. Last week, I think I have figured out who killed our 2' striped distichodus aka Distichodus sexfasciatus - see post #2 above.
It was the paroons and it happened overnight, so I missed it, I could not have witnessed it. I was wondering why pretty much all the scales have been removed from the Distichodus and also while it was nearly dead in the morning, I witnessed paroons biting it and as if trying to fit it in the mouth but quickly realizing they couldn't. But I thought the paroons have done that since the Distichodus was already almost dead, barely moving.
Also when any other fish would fall victim in that 4500 gal, the scales would only be missing from the rear end (e.g., in arowana) or the damage would only be confined to the rear end (e.g., in TSN or achara) as this is the only place easiest and logical to attempt to start swallowing them. So the big Distichodus missing pretty much all the scales didn't make sense.
So, as mentioned, last week, much to my dismay I got lucky and saw the paroons in the morning trying to make a meal out of our smallest pacu named Coral. Coral is an albino red belly and he is anything but edible, being about 2' long and 1.5' tall. The paroons could never fit any significant part of Coral in their mouth, just like they couldn't do that to the Distichodus.
Nevertheless, they were seeking out Coral in the tank and biting it knocking out scales by dozens. They were doing this relentlessly. I imagine that's exactly how they descaled the Distichodus overnight and it perished from all the stress by mid morning. Coral would too if I didn't feed the jackals.
It turns out that not feeding the paroons Sun, Mon, and Tues (I only offered pellets on Wed, Thurs, Friday, and Sat in that tank) meant they grew hungry and eventually started taking matters into their own fins.
That's my lesson."
