Increasing productivity and efficiency of Nile tilapia production using plant saponins and introduction of its culture in areas under the jurisdiction of the Palestinian Authority (PA)

Introduction:
Plant compounds such as saponins have been observed to have diverse effects on growth and reproduction of Nile tilapia in earlier experiments at our Department. These results point to an application for plant derived substances that could become highly relevant for aquaculture in future. Chemical substances such as methyl-testosterone have been used to achieve sex inversion in Nile tilapia, are highly hazardous. Identification of degradable and environment-friendly substances that could replace such chemicals would be timely as tilapia aquaculture is witnessing high growth rates.
A project was conceived for studying the effects of saponins of different plant origins on growth, reproduction and sex ratio of Nile tilapia. Through the involvement of a Palestinian partner, the project would also be introducing aquaculture research in areas controlled by the Palestinian Authority (PA).

Objectives:
- Isolation and concentration of saponin fractions from three plants, Q. saponaria, G. tournefortii and T. foenum-graecum
- Test their effects in vivo and/or in vitro growth, metabolism and sex inversion in Nile tilapia
- Obtain insight into the mode of action of the saponins
- Practical use of saponins in fish production.
- To identify and chemically modify the biological active saponin fractions to increase their effectiveness
- Capacity building and training of personnel in aquaculture research at Al-Quds University in Abu Dis, West Bank
- To identify locally available protein sources that could form fish feed ingredients in the PA areas.

Progress so far:
Saponin fractions have been isolated from Q. saponaria and T. foenum-graecum. The isolated saponin fractions have been tested for effectiveness using the newly developed aromatase assay and the active fractions identified. These fractions are being tested in vivo in Hohenheim. A warm water recirculation unit for aquaculture nutrition research has been installed and tested at Al Quds University, personnel trained.