Aggressive Fish

[fishn10s]

What are some guidelines or recommendations for dealing with an aggressive fish. I know it can lead to stress and the eventual death of the fish being chased and nipped at. Is it adviseable to try and remove the aggressive fish? What is the way that some of you aquarist deal with an aggressive fish in your tank?

Also any suggestions in catching a fish in a 75 gallon tank for whatever reason?

Thanks in advance for any response! :)

[DaisyTattoo]

Personally, if I have an aggressive fish that is tormenting its tankmates, I will take it back to the LFS. You need to look for a reason for the aggression however. Overstocking is a common cause. Lack of barriers, such as rocks, driftwood, caves, plants, whatnot can cause aggression for some fish. Stress in general will also cause aggression. So I would make sure my water parameters were all in check.

[mostlycichlids]

Sometimes removing the fish for a day or two may help try removing him and putting him back after the lights go out. more hiding places help too and devide the territories with plants.

[Ms.Bubbles]

Sometimes adding more fish can help spread the aggression around so that 1 or 2 fish aren't getting all the attention. Of course, you need a tank that is not overstocked to do this. That said, I personally opted for returning my aggressive fish to the LFS. Life's too short for bullies!

[mostlycichlids]

I too would return it if other things dont work some are just more agressive than others. I personally think I have one of the most agressive firemouths on earth. He likes to think he owns 60% of my 55 gallon his mates are 2 convicts and 4 pictus catfish he is always chasing them out of his end I like him too much to take him back so I just make him mad once in a while and move their territories around.

[plah831]

I think the best way to deal with aggression is to avoid it in the first place. In other words, do your research on species and compatibility, and stock accordingly. However, as akapaul said, it's still possible to get a fluke fish that is unusually aggressive.

As stated, breaking up lines of sight will help quell aggression. Understocking is one of the best ways to prevent aggression, because behavior gets all out of whack when fish are forced into smaller "personal" space. Imagine having to share a studio apartment with 10 other people. Even if they used to be your best friends, the stress of getting in each other's way every day will lead to problems.

While it might seem contradictory that ADDING fish could help aggression, it's only because it helps diffuse the energy to more than one fish (as Ms. Bubbles said). It won't actually get rid of the cause of the aggression, though. This is a common technique employed by cichlid keepers, who know to expect their fish to fight.

If you can't return the fish to the store, other solutions I've made were to buy a separate tank for the bully. I have a male molly who was too aggressive to play well with others. I wanted to donate him to a store, but my boyfriend liked him too much to let me give him away. So he bought him a whole new tank.

Other solutions I've used were tank dividers. If the fish is REALLy aggressive, though, just the sight of the other fish may send it into fits and it might end up hurting itself on the divider. I currently use one between the molly and my male betta, and they ignore each other, luckily. That tank is my "bachelor pad" :D

[plah831]

oh, yeah. a good way to catch a fish in a larger tank is remove as many decorations as you can. Then use some kind of divider (a plank of wood would work in a pinch) to corral the fish into a smaller area. The divider should be nearly as wide as your tank. In other words, the idea is to effectively reduce the volume available for the fish to escape from the net.

If you manage to plop the divider between the offender and the other fish, and it happens to be right near the end of the tank, you might not need to remove any decorations at all!

[DaisyTattoo]

You can also use waterchange time as an opportunity to catch a fish. It is much easier to catch them when there is less water volume. When you have the water down as far as you are going to take it, then corral him into a corner. I use a large net and a smaller net to block them in. You are pretty likely to catch them with at least one net. Plah's method would work as well, just make sure the wood is safe for the aquarium. Other wise you might try a cookie sheet, rinsed well, of course, or possibly some tupperware.

[fishn10s]

Personally, if I have an aggressive fish that is tormenting its tankmates, I will take it back to the LFS. You need to look for a reason for the aggression however. Overstocking is a common cause. Lack of barriers, such as rocks, driftwood, caves, plants, whatnot can cause aggression for some fish. Stress in general will also cause aggression. So I would make sure my water parameters were all in check.
I would not really classify this fish as tormenting the other fish. It is a rainbow and is picking at the 2 other smaller rainbows in my community tank. My tank is not overstocked, the water perameter are perfect, and there is much artificial plants and drift wood to hide. It is not constantly but often I will see him chasing and picking at the other 2 rainbows. At times they are OK. If I consider removing the aggressive fish, any suggestions for catching him?

[fishn10s]

Thanks very much for the input. All really good information and ideas!

Dan

[mostlycichlids]

let out some of the water into a bucket try to use a net and and a plastic container. Try to encourage him in to the container with the net then put the net over the container and remove it from the water or use two nets just be careful.

[DaisyTattoo]

Is he a rainbow shark? If so you should only have 1 per tank. They will always do this to any fish that are similar in shape such as other rainbows, red tailed black sharks, flying foxes, ect. I tried to keep 2 as well and they did not do well. They get worse as they mature. I would recommend rehoming 2 of them and the third will probably not cause you any problems.

[plah831]

I interpreted that it was a rainbow fish, Melanotaenia (the ones Roan is fond of). If so, I think they need larger schools, like at least 6, otherwise their behavior is not normal. I've noticed this with white cloud minnows and danios, that even if there are 3 or 4, one of them ends up being a bully toward the others.

[fishn10s]

Is he a rainbow shark? If so you should only have 1 per tank. They will always do this to any fish that are similar in shape such as other rainbows, red tailed black sharks, flying foxes, ect. I tried to keep 2 as well and they did not do well. They get worse as they mature. I would recommend rehoming 2 of them and the third will probably not cause you any problems.
Sorry, I am new to fresh water fish keeping and don't know the names well. The culprit is a Boemamani Rainbow and the fish he is bothering are neon rainbows. It seems to me the literature is not saying they are very compatible. My plan is to remove and return it and get a couple more neon rainbows. I purchased the fish from what I thought was a knowlegable fish store. They have been around a long time and and the store and displays are really nice and clean. I have since lost confidence in them because of this advice they gave and also more regarding Bio Spira. I asked if it was important to refrigerate as I wasn't going home right away and he said of course. He said that it is only refrigerated to extend its shelf life. I have since researched and found out if it is not refrigerated, the bacteria will die! I'll need to work on finding a nice dependable store with accurate information.