Are OB Zebras all Female?

I just read that most OB Zebras, or at least the bright ones are females.
http://www.cichlid-forum.com/profiles/s ... hp?id=2316

Could this be true? I totally thought mine was a male due to it's somewhat agressive behavior towards other males and because it has 6 egg spots.

Also, I noticed a different listing for metriaclima zebra and metriaclima estherae. I thought zebra simply included estherae and callainos and so was less specific. Is it a different species?

Thanks