Hey :D
I've got some smaller Mbuna that need to be vent sexed.
What type of optical device is best?
Do i need a special light?
Any tips or tricks?
Thanks.
Google is the best way to get the info you want.
Sexing young fish is not easy or even older ones of some species.
Below is a link to a good page to get you going, after that do a bit of Googling.
http://www.fishhead.com/articles/ventsex.htm.
Theo