Maturing Harem Massacre? Thoughts?

[Unknownpharoah1]

When I started my tank around 6 months ago, the first real color I put in the tank after testing was deemed "OK" to introduce fish was installed a harem of blizzard clowns. I went with the suggested 12 each, juveniles, probably an inch in size or so and introduced them to the 500-gallon tank. For the last 6 months life was going relatively smooth. The group would brood together, swim together and pretty much stay in the tight ball when swimming around the tank.

That all changed over the weekend.

I came to the office and noticed I was missing a few clowns. Nothing new actually. I have often had the little ones slip into the overflows and travel down to the sump and/or I have them retrieved from the overflows and put them back in with the brood. No big deal. Well, this morning after some looking around it was clear I was missing a handful of clowns, and few were on their last legs. Fins tattered, nonexistent and bit marks a plenty.

I also noticed our CUC was having a field day cleaning up the mess. Snails, crabs & hermits having a feed on multiple fish until I could get them out. That was also a giveaway as to how many ended up deceased over the weekend.

I decided to feed and observe.

Sure enough, when it was time to eat, two of the clowns, chased, nipped and pushed the other clowns out of the feeding space. Persistently and with force. This left me with no doubt the two biggest and healthiest clowns decided to assert some dominance and thin the herd per se.

I witnessed a similar behavior with our Blue Chromis. We started with 8 and they whittled themselves down to 4 healthy fish. No surprise, the biggest ones survived.

I made the choice to remove the remaining clowns and put them in a 30gallon qt tank until I sort out what's next. Rehome them or just keep the biggest two and save me hours of trying to catch little fish in a large tank. So far, the same two are healthy and strong. The rest in the tank are tattered and look to have been through a war zone over the last 72 hours.

The reason for the background information is to ask the group if this is "normal"? Not knowing much about clowns when I started, I took the advice of a trusted fish friend and went with a Harem. This was supposed to alleviate the possibility of the clowns killing one another to sort out the female in the group. I have a feeling; however, nature is unpredictable, and this is a situation not unique to myself or other professional clown keepers.

Am I wrong? Is this to be expected or a calculated risk at the very least? Have you had a similar story? Rehome the remaining and keep the two strongest?

Let me know what you think. I'm all eyes.

 

[Stigigemla]

First of all You should not have a feeding space.
Clownfish are very aggressive at food and heavily inbred clowns have been selected to grow fast among many other individuals. The natural behavor of looking for aggressors is reduced due to the breeding selection.

If You broadcast the feeding over the whole tank the fishes will be spread all over the tank when they eat .
The aggressors cant attack the same fish as much when it is trying to eat. And the small have more time to eat because the aggressive ones does not see the whole tank.

The best way to start a harem is normally to have one big boss and the rest small so the boss dont see the small ones as food competitors. And the boss rules.

 

[New&no clue]

I am no expert, but I wanted to do an anemone clownfish tank and did lots of research. I have seen this happening in a fair amount of tanks. You can do several things to reduce aggression, including feeding often and at multiple spots in the tank and having multiple anemones for them to spread out. Also, having a large enough tank and rockwork for smaller ones to hide if need be. However, it seems like once the aggression starts, it's hard to get it back together. I've seen some beautiful tanks where it works, but it seems far more where it ends similar to your story.