Bangaii Cardinal Aggression

[cwatkins]

Hi All,

We bought 2 bangaii's several weeks ago to have a pair as I read that in a pair they should be okay.

One didn't make it though acclimitization for some reason, and the other one came out perfect just like all fish usually do, so the LFS replaced him several weeks later when they received a new shipment.

Well in the mean time the one by himself has fattened up and I guess is all used to being the only cardinal in the tank. So when the new one arrived, he's begun to be aggressive towards it.

Not nipping, but pushing him around, backing into him, chasing him to and fro, cornering him in the top corners of the tank, etc.

Is this okay aggression as in they may form a bond? Or is this bad and I should remove one to the refuge for a while until he gets used to being fed my food, etc?

I haven't seen him eat yet (I've been watching closely). But it did take the other cardinal until day 3 to start eating.

Any thoughts or suggestions?

Thanks.

[Borderjumper]

For 2 cards to get along they need to be a male/female pair. It sounds to me like you have 2 males. The stronger one will end up killing the weaker one.

I find the females tend to bicker some, but nothing too serious. Males on the other hand will bully each other to death.

[cwatkins]

Thanks for the info, I never even thought about that.

Does anyone have a definitive way to differentiate male and female cardinals? (or an online resource?). A quick google didn't pull much up.

I may put one in a QT and then return him for a fish of the correct (opposite) gender. (I'm not interested in breeding, just peace and harmony among the fish).

Thanks!

[cwatkins]

Ok, I've got him in a QT tank to see if he'll start eating now that he's not being picked on. Any easy way to determine gender in this fish?

[Nebthet]

Determining Cardinal sex is very hard. Most people cannot tell the difference until after they have bred with each other.

One way to tell is to take a very very very close look at the anal vents of both of your fish.
The male with have too little v's pointing down and will look sort of like this ... v--v.
The female will only have one.. --v--.
These are very hard to see and you may need a magnifying glass.

Additional indicators that can help are: The female has more of a u shaped jawline while the male has a V like that rounds out at the bottom jawline.

The second dorsal fin of the male is much longer and usually reaches back in a flag like manner and at least reaches to the end of the tail. The female's won't reach that far. Also I have found many of the male's dorsal fins have a v like break to them.

http://www.marinebreeder.org/phpbb/viewtopic.php?f=166&t=2064

http://www.reefs.org/library/talklog/k_clarke_102499/3.html

http://www.reefcentral.com/forums/showthread.php?t=1659511&page=5

http://www.marinebreeder.org/phpbb/viewtopic.php?f=166&t=1295