True piraiba aka Brachyplatystoma filamentosum

[thebiggerthebetter]

Thank you, Joshua.

Truly interesting, I wonder what is triggering the predatory behavior? Is it possible they are like that in the wild? Severely opportunistic to the point that they are almost like fin and scale eaters and attack anything within a set vicinity around them? Hard to imagine as that seems like such a waste of energy for such a large fish to expend for so little reward. I truly do hope you figure it our as I find the predatory behavior very interesting.

I believe I have started to figure it out... Not just opportunistic. Predatory. Very predatory. The predatory nature triggers the predatory behavior, I think as simple as that. It's just that in some predators, such as piraiba, paroon shark, and the likes, the predatory instinct is the strongest and indiscriminate, open water pursuit predator instinct, not taking no for answers... If they feel hunger or simply that they could eat some more, they attack. Period. Doesn't matter much what tank mate, unless clearly bigger than them. As I said before - kill first, ask the questions about "swallowability" later.

No, they don't go for fins and scales. They appear to simply not understand if they can or cannot swallow the prey until they try, or kill it and try... and try again.

 

[koltsixx]

Thank you, Joshua.



I believe I have started to figure it out... Not just opportunistic. Predatory. Very predatory. The predatory nature triggers the predatory behavior, I think as simple as that. It's just that in some predators, such as piraiba, paroon shark, and the likes, the predatory instinct is the strongest and indiscriminate, open water pursuit predator instinct, not taking no for answers... If they feel hunger or simply that they could eat some more, they attack. Period. Doesn't matter much what tank mate, unless clearly bigger than them. As I said before - kill first, ask the questions about "swallowability" later.

No, they don't go for fins and scales. They appear to simply not understand if they can or cannot swallow the prey until they try, or kill it and try... and try again.

I just meant that they maybe instinctually driven similarly to fin and scale eaters in the fact that they are instinctually driven to attack anything regardless of how full they are. I didn't mean that they target scales and fins, sorry for the misunderstanding.

Oh and I meant to mention it before but I believe you have inspired others to make long term update threads as while they are few and far between the ones we do have on MFK in recent history are of great quality in my humble opinion. And I believe your threads maybe, whether consciously or not; be the inspiration for some of these threads.

 

[thebiggerthebetter]

One or both Peru piraiba in the 4500 gal tank attacked Big Bad, the dovii. When I discovered it in the morning, it was too late. The dovii went into a shock and never came out of it. Ever since they attacked a marble Pim catfish two weeks ago, I started feeding them 2x more... but obviously still not enough, or maybe it's the season to gorge up on food. Fish go through such seasons.

 

[koltsixx]

I am so sorry for your loss Viktor , Big Bad was a real beauty. I've had only two Dovii but they have earned a special place in my heart. I had a pair of Red Dovii, unfortunately I lost my female to TSN/Achara hybrid aggression. I've had TSN/Achara before but never experienced aggression until these two. They where targets of my Hemibagrus Filamentus aggression when they where younger, don't know if that spurned them on toward their present disposition. But they are aggressive toward all their tankmates, luckily their primary tankmates are Silver Dollars which as you mentioned about Pacus likewise the SD's are surprisingly nimble so avoid the aggression.

Anyway I am almost positive it was the Hybrids, they targeted the female in the night and she jumped. I had seen them chase her to the surface on many occasions but the male would step in. Despite being Dovii and never having bred or bonded that I was aware of they didn't show any aggression toward one another. I regret not moving them but I felt I had nowhere to put the Dovii or the Hybrids other then where they where. Fearing in my other tanks they'd just become a meal. I still have the male and I have seen beautiful females for sale but never got one because I worry the harmony I lucked into won't happen again and I'd just lose another Dovii. Sorry, I am not trying to overshadow your loss, it's just I think I know how you feel. I was pretty devastated and still am. So again I am so sorry.

I don't know what you are going to do about the Piraiba. I wish I could give some helpful advice, I just hope they aren't like my Trachys. As I have mentioned in the past my female Trachy goes on binges, perhaps brought on by breeding season stimuli? Where she starts trying to eat everything in her tank that has a heartbeat. She handfeeds so feeding her till she almost bursts is easy but regardless of how bloated her belly is she becomes a dangerous predator during these times.

 

[thebiggerthebetter]

Thank you so much Kolt for sharing your experience and thoughts. Always welcome and always love to read them.

I too am surprised that your TSNxachara (2-3?) would chase after a dovii. It must have been predatory? What were their sizes - the catfish and the cichlids? In our hands the TSNxachara hybrids have been placid and reserved to themselves for the most part, unless attacked / provoked by a tank mate like a Jau catfish. It's amazing how much more we find out from each other.

For now, I am feeding the piraibas until firm refusal. We have nowhere to move them of their 50 tank mates. Yes, right now, mid-spring, is the right time for excessive feeding in preparation to the breeding season, so I think this sudden and significant surge in predatory behavior likely has to do with it.

 

[koltsixx]

Thank you Viktor, I appreciate that especially since I know I can be long winded. Lol

At the time the Dovii female was around 5 inches and the 2 TSN/Achara about 3-4 inches at most. I don't think it's predatory?, as they regularly attack everything including each other. They're a little over 8 inches now and always have tattered fins and have attacked the Platydoras sp. Maroni so much I rehomed him with the Trachys and that fish is 12+ inches easy and his body is massive giving my Trachys a run for the money for being thick bodied. They also attacked my Serratus Pleco whose 12+ inches and that is one thorny big fish.

They used to fight with the H. Filamentus too but the Fila is semi-aggressive. The Fila resides with the Trachy's now too and gets into minor scuffles with a 10 inch Syno Nigrita and 2 10-12 inch Cranoglanis but ignores the Maroni but occasionally gives my 2 Litho Dorsalis half hearted chases. It's usually easy to tell predation from aggression at least if my observations are correct. Predators I believe try to catch prey unaware and attack from blind spots and do so stealthily trying not to do anything to alert the prey. While in my observations aggression is all about being seen usually with display and fins extended. The TSN/Achara gills flare all fins fully extended they seem to try to be seen before they attack and the attack itself has displays, turning their body lengthwise to the target and flailing their body with fins erect. I am very surprise and confused but that's the way it seems to me. Previously I had a 2 TSN/Achara that hit 14 inches in my care before I sold them and I never saw any aggression at all. But then again I have seen aggression before in fish I would never have expected. Perhaps it's my decor? Fighting for the best hides?

I know you have nowhere to put those big guys, that's why I am at a loss because from what you describe that would probably be the best option. I hope it's just some hormonal and temporary phase for them. I had suggested sexual maturity being the cause for possible aggression with your Piraiba incorrectly but perhaps it's responsible for the predation and hopefully it's like they hit their teens and will grow out of it.

 

[thebiggerthebetter]

The two killers fed to the max:

 

[thebiggerthebetter]

 

[thebiggerthebetter]

The two Peru piraiba have not bothered other tank mates since we started feeding them until refusal.

 

[thebiggerthebetter]

The 5ft / 1.5m piraiba got attacked by two 3.5ft / 1m paroon shark catfish, who were not supposed to be hungry but maybe it is the breeding season that drives them to doing things like this. Paroons do have a bad reputation from some peers of being outright killers and predators, which is coming more and more true with years in our own experience. They will need to be separated from tank mates and maybe even from each other at some point, if it continues like so.