Behavior of Oscar

Question
QUESTION: Hi dear Ron,

First of all I'd like to request you for a rapid reply as I need that eagerly. I'm a bit confused about my two black tiger oscar. They were fine all these days but but very recently they are showing strange behavior. Shivering tail n body, lips inter-locking, cleaning hard surfaces are as called to be the sign of mating, along with these they are injuring each other violently mainly the male is suffering more. I've placed an net partition within them but they are not allowing that but how can I let them fight, they are very young(1.3 years)and its their first maturity.

Tube attained in One of them n other isn't. What I should do now? Is it normal normal behavior for them? (tank size 18 gallon(uk), one power filter, one HOB under gravel filter, pH 7.5, individual fish size 6" +/- 0.5", water exchange frequency= once per weak)

Please Reply As Early As U Can.
sincerly,
Rakib

ANSWER: Hi Rakib,
  This sort of fighting is normal for cichlids.  You have them in a VERY small tank for two oscars.  Keep in mind that an adult oscar is 12-16" (30-40cm) in length and they can reach that size in little over a year if well maintained.  If you have two oscars in a very small space they are going to fight until one kills the other.

 I am curious how you know which sex they are?  There are no external ways of telling the sex of an oscar, i.e., males and females look the same. People will tell you that they can sex an oscar -- they will be right 50% of the time, but also wrong 50% of the time.

-- Ron
  rcoleman@cichlidresearch.com
  Cichlid Research Home Page <http://cichlidresearch.com>


---------- FOLLOW-UP ----------

QUESTION: Thanks for the quick response. Though I believe that my tank is small enough to house two Oscars but they are only 6.5" and around in size, smaller space could be the reason of hindering the growth. I guess the sex depending on the direction of the genital tube as in some site I found that difference. Actually they are not fighting all the time rather occasionally, most the time they are coping each other and cleaning several hard substrates of the tank.

So what is your suggestion now, shift them in a new tank or anything else you think is better.

Answer
Hi Rabik,
 If you are seeing the genital tubes then they are getting ready to spawn.  I would leave them alone.  A certain amount of fighting just prior to spawning is very normal for oscars.

 You should definitely plan on getting a larger tank for them in the very near future and move them into it after this spawning is done (e.g., after the kids are free-swimming for several weeks.

-- Ron
  rcoleman@cichlidresearch.com
  Cichlid Research Home Page <http://cichlidresearch.com>