I have 2 oscars together they are about 8 inches long and 3 years old. I have recently noticed them fin shaking locking lips and noseling each others side. The fin shaking was the first thing I noticed one would start and do 3 of 4 shakes then the other would do the same thing. I only saw them do the lip lock once. The noseling doesn't seem to be teribly aggressive just kind of a light nudge that does not apprea to get much reaction out of the other fish.
Every thing I have read has said that it could be spawning or territorial fights. Is there a reliable way of determining which is going on? Both fish are very close to the same size.

what size tank do you have them in?

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90 gallon mixed reef
20 gallon cichlid tank
14 gallon (saltwater) Biocube &
10 gallon nano reef tank!

They are in a 55 gallon.

well, in that size of a tank it's probably not territorial, and since they are the about the same size, it's probably not bullying either. but I wouldn't know much about Oscar spawning. I hope I helped a little! hehe. best of wishes!

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90 gallon mixed reef
20 gallon cichlid tank
14 gallon (saltwater) Biocube &
10 gallon nano reef tank!

Are there any oscar experts out there?

It could be territorial as 1 full grown oscar needs a 75 gal to be able to get around easily. One oscar will claim an entire tank for itself. Unless you know for sure that you have male and female its going to be territorial.

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SUCCESS IS MEASURED BY YEARS, NOT MONTHS!!!
220 Tank build
http://www.aquariumforum.com/f15/sta...late-3253.html

They are showing aggressive behavior.They also need to be in a larger tank.Oscars average 12 to 14 inches,they usually reach that size shortly after a year.3 year old Oscars that are only 8 inches does not sound healthy to me.It sounds like they are stunted.Try to find them a larger tank,75 gallons would work,but if you could find a 5 or 6 foot tank,that would be even better.Since they are still getting along in the 55,the stunting has probably not had any severe health issues,but it may shorten their life.When and if you do get them a larger tank,they still may show aggressive behavior,then fin shake and lip locking.Nothing to really to worry about.It's common behavior in cichlids.

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rose schmoze.

Hmm ok bigger tank.
The weird thing is they seem to have completly stopped all 3 behaviors.

I have only had them for about 3 months and they have grown at least an inch in that time. I suppose it is possible that the guy I got them from did not tell me the truth about their age, or did not feed them properly.

Well my wife said the oscars were only 6 months when we got them. I could have sworn that the guy said 3 years.

The wierd thing is they almost never leave the right hand side of the tank.
But we do have a larger tank but it will take a while to get it set up and cycled. So hope fully thing wont get too heated.

Thanks for the replies.