Distinguishing Male from Female Tilapia
“One of the challenges of rearing tilapia is being able to successfully distinguish male from female tilapia. This is important when setting up breed stock or enhancing production rates.
Tilapia grown in pond culture can have a problem with excess reproduction. This can lead to stunted growth and lower production rates.
To prevent this problem, farmers can use monosex culture by separating the males from females. Typically, males are preferred because they grow to a larger size and have greater profit potential.
Home growers can use tilapia behavior to help sex their tilapia. Put a small number of tilapia in an aquarium along with some gravel. The male will typically dig a nest and defend it. Females will tend to hide unless they are spawning. You can remove males that display nesting behavior one by one and move them to separate containers. When the remaining fish no longer show nesting behavior, then you can assume they are all females. You can add one of the males back into the aquarium and start a breeding colony.”
Article taken from Tilapia Farming News, Volume 1, Issue 2, tilapia-farming.com