yellow halichoeres wrasse aggression

[TheStrangler]

Heres a head scratcher, the most aggressive fish in my tank at the moment is a ~3 inch juvenile yellow halichoeres wrasse (not white/purple bottom cousins). The tank is 150 gallons with tons of hiding spots so at this moment its just more annoying than a danger to my other fish, no fin nipping just chasing and fins flaring. It chases my ~2 inch adorned wrasse into a corner and orchid dottyback into hiding anytime they see each other which is reasonably often as the yellow wrasse is constantly patrolling the whole tank. I feed three times per day and everything is healthy and well fed so its definitely not food aggression. I'm weighing my options such as: catching and putting the yellow wrasse into an acclimation box, hurrying up adding my final fish, a bristletooth tang in the hopes that it'll take over as the boss and mellow the wrasse out, waiting it out until the adorned and orchid are bigger and can hold their own, or getting rid of the yellow wrasse which would be a shame. Any thoughts? Its sort of uncommon to come across a problematic yellow wrasse so I'm not entirely sure what to do.

Current stocking:
2 clowns
foxface
copperband butterfly
adorned wrasse
rhomboid wrasse (the yellow has no issues with it as they're similar sized?)
orchid dottyback
dracula goby
zebra goby

 

[Daniel@R2R]

@Jay Hemdal #fishmedics do you guys have any wisdom on this one?

 

[blecki]

Fish are individuals... could just be a jerk. can you clarify, this is the all-yellow kind? Not the kind with the white belly?

I wouldn't rule out the dottyback as instigating either. If the adorned wrasse is a new addition the yellow wrasse may just be asserting dominance and will stop once the other wrasse accepts it. Acclimation box is probably the first thing I'd try but you know, good luck catching it. A mirror may help calm it down a bit.

Or - he's going through the transition to male and is so full of testosterone that he wants to fight everything.

 

[Jay Hemdal]

Heres a head scratcher, the most aggressive fish in my tank at the moment is a ~3 inch juvenile yellow halichoeres wrasse (not white/purple bottom cousins). The tank is 150 gallons with tons of hiding spots so at this moment its just more annoying than a danger to my other fish, no fin nipping just chasing and fins flaring. It chases my ~2 inch adorned wrasse into a corner and orchid dottyback into hiding anytime they see each other which is reasonably often as the yellow wrasse is constantly patrolling the whole tank. I feed three times per day and everything is healthy and well fed so its definitely not food aggression. I'm weighing my options such as: catching and putting the yellow wrasse into an acclimation box, hurrying up adding my final fish, a bristletooth tang in the hopes that it'll take over as the boss and mellow the wrasse out, waiting it out until the adorned and orchid are bigger and can hold their own, or getting rid of the yellow wrasse which would be a shame. Any thoughts? Its sort of uncommon to come across a problematic yellow wrasse so I'm not entirely sure what to do.

Current stocking:
2 clowns
foxface
copperband butterfly
adorned wrasse
rhomboid wrasse (the yellow has no issues with it as they're similar sized?)
orchid dottyback
dracula goby
zebra goby

Fish compatibility can vary between individuals, changes over time and is always mostly unpredictable. It is unlikely to be food motivated in this case.

In this case, the wrasse has set up a territory and is defending it against some fish. It is unfortunate, but in many cases like this, the territory extends beyond the sides of the tank, so the fish getting picked on have to hide. There are some tricks - moving the tank's rocks around (not always possible) can disrupt the territory, but that is usually temporary. Adding more fish, like you mentioned with the tang *sometimes* works, but in other cases, it can make the situation worse - for example, what if the wrasse and tang ignore each other, but the tang starts going after the more closely related foxface, or vice versa? Some people have tried adding a mirror to the end of the tank. That sometimes works to redirect tang aggression. It probably won't help with a wrasse, but worth a try.

 

[TheStrangler]

Fish are individuals... could just be a jerk. can you clarify, this is the all-yellow kind? Not the kind with the white belly?

I wouldn't rule out the dottyback as instigating either. If the adorned wrasse is a new addition the yellow wrasse may just be asserting dominance and will stop once the other wrasse accepts it. Acclimation box is probably the first thing I'd try but you know, good luck catching it. A mirror may help calm it down a bit.

Or - he's going through the transition to male and is so full of testosterone that he wants to fight everything.

Sorry guess I had notifications off so I missed the replies here. Yup, all yellow. Dottyback isn't instigating, its pretty mellow but its not at the level of nonstop aggression. They're all able to eat, no nipped fins. Just random chasing into rock crevices. Besides that the fish seem fine, aren't skittish except for when they're actively being chased, and seem healthy. I figured it was a big enough tank that eventually they'd just avoid each other but the wrasse patrols the whole area looking for treats to pick off of the sand/glass/rocks so it runs into everyone pretty frequently. It doesn't seem to care about mirrors or its own reflection but after close examination I'm seeing some orange forming on its head though it still has the juvenile black spots on its fins. My guess is that you're right, its transitioning and is feeling extra feisty.

Fish compatibility can vary between individuals, changes over time and is always mostly unpredictable. It is unlikely to be food motivated in this case.

In this case, the wrasse has set up a territory and is defending it against some fish. It is unfortunate, but in many cases like this, the territory extends beyond the sides of the tank, so the fish getting picked on have to hide. There are some tricks - moving the tank's rocks around (not always possible) can disrupt the territory, but that is usually temporary. Adding more fish, like you mentioned with the tang *sometimes* works, but in other cases, it can make the situation worse - for example, what if the wrasse and tang ignore each other, but the tang starts going after the more closely related foxface, or vice versa? Some people have tried adding a mirror to the end of the tank. That sometimes works to redirect tang aggression. It probably won't help with a wrasse, but worth a try.

I actually had a rerockscaping in the works, I'm moving around everything so hopefully it helps. Like I mentioned its not critical levels of aggression. Nobody is injured, everything gets to eat, so I'm going to keep taking small steps to see if I notice any changes.