Hello guest! Are you an Apistogramma enthusiast? If so we invite you to join our community and see what it has to offer. Our site is specifically designed for you and it's a great place for Apisto enthusiasts to meet online. Once you join you'll be able to post messages, upload pictures of your fish and tanks and have a great time with other Apisto enthusiasts. Sign up today!
The standard for non-dimorphic fish in a slight color difference and a difference in the length of the rays of the fins. in fully mature fish. This subject has been discussed numerous times in the past here and alot of information can be found by running a search.
Just type in bolivian rams and you will find a ton of info.
joopsg,
By the way, I deleted your other post in the Husbandry/Breeding forum because it was exactly the same as this one. I think that this is a more appropriate place to discuss sexing issues of this South American Dwarf Cichlid.
Neil
Don't know if this is mentioned in any of the older posts, but I also use the abdominal profile to help me determine the sex of Bolivian rams. It is flat to slightly concave on males and slightly convex on females. I've also noticed males to have a slightly goldish sheen on the body while females are a somewhat drabber gray.