Hi,
My 6" NA Sunfish is acting different.
After waterchanges he has been doing this:
He goes up to the middle of the tank and slowly but very fimly wags his tail through the subsate.
He created a 15" crater and starts guarding it.
Man, he chases my silver dollars away.
He threw over my ornament and is making a mess.
At first I suspected my oscar(of course...) or plecos to have made this mess.
I thought he was hunting first but it seems like a mating ritual.
Anyone any ideas, for you may know this behaviour from your oscars!
Let me know!
Greetz, Noddy

sounds like he is trying to make a breeding territory for his non-existent mate, and gaurding it.
just a guess

centarchids are rather territorial, he's just declaring his space

Noddy wrote:
man... that is just a sign of maturing sunfish. the crater
is now her homes and nobody should get near to that.

So, this may be a permanent thing?
Thats bad, she is almost forcing the silver dollars out of the tank!
And the spot is exactly in the front-middle of the tank.
Soo the whole tank seems to be taken as territory.
I'll see what happens next....
Luckily Sunfish are sold as Pondfish here in Holland and I can rehome if nescesary.

you can try the magic bag of BGH. out him/her in a bag or net
for 6 hours floating inside the tank. then release afterward,
he will lost his/her teritorial domain, and will act differently.
try it and let us know.

Thats surely worth a try!
I mean, if he keeps behaving like this he still has to be caught.
Better to reprogram him, instead of giving him up!!!
It will be this weekend,if he still behaves bad,when i do my waterchange.
I'll let you know, thanx in advance!

it will work .......i have used it many many times but only on other species of cichlid and for aggro behaviour against their tankmates use the search facility for "time out bag"

the master of that concept had spoken...
i totally concur with him (BGH)

I think my Sunfish is 2 years now.


At what age does a Oscar mature?
I mean at what age could he become territorial?
Mine is 6 months old now and still very,very gentle.
He resolves to sulking if anything disturbes him, but is allways prepared to change his mood when I offer him something to eat!!!

Have you known any oscars that had a "personality-change" after becoming
an adult?

oscar, like other fish is unprdictable. some become hostile
when matured, some remains gentle even if fully grown up. nobody
could tell what would they become or how they would react with
tankmates especially when it is one of a kind in a tank.
however, when they are pair or more than two, then buddying
and pairing change their mode. the male may want to establish
territorial supremacy, or if courting start, want to assert
dominance until the female submit or damage... if female,
mostly are gentlier to tankmate.

OK, just to be curious, Paul,
I see your oscars are 1,5 kg each.
Did you get them as babies, and how long did it take them to reach fysical maturity?
Mine is 9"after six months and I was just wondering how long he may continue growing?