Bloody rams. Now what?

[Gypsum]

As per my other threads, I upgraded to a 240L tank a couple days ago. Tonight, the Bolivian ram has staked out a territory and tried to pick fights with the raphael catfish. The catfish would rather not have a fight and swims away. So far, he's not shown aggression towards his other tankmates (a juvenile bristlenose, some corys, some tetras, and some rasboras) but it's a sudden change in behaviour. He's been very peaceful since I rehomed the other male ram and hasn't bothered arguing with other species.

Is there anything to be concerned about? I know the raphael is both armored and bigger, so she could fend for herself if she wanted to, but I don't want this ram acting aggressive towards anything else in the tank. You'd think the fish would be less territorial in a larger tank.

 

[Byron]

If the fish targeted by the ram--and I can assure you that these will inevitably be substrate-level/feeding fish because that is the Ram's area--are fairly tough they can usually manage by simply swimming away. If the Ram decides to pursue them, that is a different matter, as the constant bullying will weaken the targeted fish and it will likely die if not separated. But assuming normal Ram behaviour, likely not much of a problem.

Your view of the Ram's territoriality is a bit off. The Ram considers the entire tank his space. In the other thread I described how my male Bolivian in a 5-foot (115g, 435 liter) tank owned all of it, and all the other 150 or so fish knew it. This is the inherent nature of the species. While some individual fish can enforce this ownership more aggressively than others might, it is to be expected because it is "in their genes" so to speak.

The area you saw him defending was probably his selected eating spot. Mine used to push away the cories who decided to chomp down on the disk/tablet/pellet the Ram wanted, but it never went further, and cories are fairly well "armoured" to easily handle pushing and shoving. It is when the Ram loses patience and raises the aggression that it can be a real problem.

Another aspect of this is that this male previously got rid of a rival so now he is all the more ready to exert his dominance.

 

[Gypsum]

The ram has resumed his normal, peaceful behaviour and not chasing tankmates. In hindsight, I think he was defending the remnants of an algae wafer. He goes nuts for the things.

 

[Byron]

The ram has resumed his normal, peaceful behaviour and not chasing tankmates. In hindsight, I think he was defending the remnants of an algae wafer. He goes nuts for the things.

Yes, that is likely. My Ram "protected" his chosen wafer from the cories every meal.

 

[seangee]

Haha my Bristlenose is the same with his wafers. His chosen mechanism is to lie on top of it. Fortunately he is (usually) quite relaxed about the cories burrowing their way between him and the sand to get to it.