Clownfish suddenly acting very aggressive

[dsaundry]

Your clowns are probably setting up to breed. They are establishing territory and any fish they deem a threat will be chased off. I have a maroon clown in a 90g and it is in with a trigger, purple tang, and even though it is the smallest fish in the tank, there is no doubt who the boss is. Its his tank and he protects his anemones fearlessly..You may find it settles down if there are lots of hiding spots in the tank, if not you may find a dead fish one day.

[marciemp]

The thing that is weird is that the clownfish look like they have been getting ready to breed since they have been in the new tank (about a year now). They established themselves in one front corner for about a week or two, then they moved to the back corner. They have been wiggling in the sand, brushing it out of the way, and wiggling against the glass ever since then. They look like obsessive compulsive fish, cleaning that corner. Like I said though, they have been doing that for about a year, but they have never laid eggs that I know of. We have only 4 groups of soft corals (zoa's), and so the clowns seem to be hosting the corner. And the agressivness only started a month ago or so. Before that everyone seemed to get along.

I feel bad for the damsel as he does seem pretty stressed. I guess if it continues we should maybe find him a new home, although he is my 4 year old daughter's fish, and we only have the one tank.

We are considering rearranging the rockwork anyway, as we are thinking of adding more rocks, maybe that would help.
Thanks,
Marcie

[PoonTang]

If your clowns are acting that agressive then they probally have already laid thier eggs. My pair laid thier first batch about 5 days ago and what a change in thier behavior. have a look very closely, the eggs are hard too see.

[BC564]

I can tell when mine have laid eggs or close to it.....they attack my hand when Im cleaning or arranging a coral....the larger one(female) has drew blood from me on occasion....she is nasty.....

[Geofrog]

Once the clownfish start to breed, they lay eggs every two to three weeks. Or at least mine do. Mine lay their eggs on the rock work right beside their host anemone. They did keep to the small area where they currently lay their eggs for some time before I noticed that they started breeding.