Blenny on Blenny Aggression

[Wandering Albatross]

Good afternoon all,

Having some blenny on blenny aggression, wondering what I can do to ease it. I expect minor dominance scuffles against new arrivals, but both fish are brand new, went in midday yesterday at the same time. No observed issues yesterday, swam and perched together in the evening before lights out and this morning. One then decided to nip the other. Hoped it was a one-time thing, cause after they perched together again. That was the smaller of the 2 nipping, and now it hunts the other one across the 5 foot tank. The smaller one has chosen a cave, the other is just wandering, much like one of my garden eels for the first day. The little one just keeps harassing the big one, and I've yet to see the big one snap back. Chasing, nipping, clear on the other side of the tank from his cave. I don't want him tore up.

I managed to get the big one out and he's resting in the sump for the moment, but I'd rather have put the more aggressive one in time out, if I could catch him. He's only been aggressive towards the larger blenny, no one else. What can I do to help alleviate this? Is it possible? He's not going to go after the mandarins when I add them is he? Would a mirror help?

 

[BryanM]

I think this is why it is generally not recommended to add two+ fish that are the same.... They are often aggressive towards each other.

You can sometimes get away with it in larger tanks, but I believe it is mostly a gamble.

I'd keep trying to catch the smaller one and relocate it for the time out, since he's living in the Ritz Carlton at the moment, he probably thinks he has won.

 

[BryanM]

Also, when I added a lot of tangs my sailfin became aggressive towards two of them.

Feeding more helped. Fat fish are less likely to be aggressive, I've read this, and experienced this first hand.

 

[Wandering Albatross]

I think this is why it is generally not recommended to add two+ fish that are the same.... They are often aggressive towards each other.

You can sometimes get away with it in larger tanks, but I believe it is mostly a gamble.

I'd keep trying to catch the smaller one and relocate it for the time out, since he's living in the Ritz Carlton at the moment, he probably thinks he has won.

I figured 150g and 5 feet worth of space would be enough for a barely 2" fish lol. Maybe I just got unlucky with 2 males. Which is funny cause the big one was not interested in fighting at all. He was just trying to mind his own business. Any advice on how to catch him? He's in one of the rocks, but to get that out I'll have to move 3 others.

 

[BryanM]

I figured 150g and 5 feet worth of space would be enough for a barely 2" fish lol. Maybe I just got unlucky with 2 males. Which is funny cause the big one was not interested in fighting at all. He was just trying to mind his own business. Any advice on how to catch him? He's in one of the rocks, but to get that out I'll have to move 3 others.

sadly no advice for any sort of fish traps. None worked for me.

When I had to rehome fish I had to take out 80% of my rock :(

 

[Wandering Albatross]

sadly no advice for any sort of fish traps. None worked for me.

When I had to rehome fish I had to take out 80% of my rock :(

That's rough...

I pried the rock out and the problem child is in a holding container to go in my sump, but now the other guy won't get out of the rubble to go in the main tank...

 

[Wandering Albatross]

Looks like some time in the clink did him good. They’ve split the tank down the middle, he hasn’t gone after the big one again, and the big one didn’t turn on him. Both are eating now, guess they just needed some time apart.

Blessings to all tanks out there