Diversity of Tilapia Oreochromis niloticus fry with Twice Sorting

Abstract

Tilapia Oreochromis niloticus is one of the important, especially freshwater, aquaculture commodity in Indonesia. The main obstacle in developing tilapia culture in Indonesia is the insufficient amount of tilapia fry. The problem lies on the quality of the produced fry. Fry quality includes genetic factor, precise harvest time, and precise size (equality of size). Generally speaking, the more fry having equal size the better their qualities are. This research aimed to observe the diversity of standard length (body length) and weight of tilapia fry with twice sorting. This research is divided into three cases, 1 control, and cumulative of all cases. Observed parameters are survival rate, standard length, weight, and the diversity of standard length and weight of tilapia fry. Sorting was carried out at the first and second month and cumulative can increase the average standard length and decrease the variance. Average standard length and diversity increased again on the next month. After three months rearing, standard deviation and CV of weight on control is relatively higher than fry population on all cases and cumulative.