| dc.description.abstract | Nile tilapia (Oreochromis niloticus) and red tilapia (Oreochromi sp.) are important aquaculture species in Vietnam. The aim of the current study was to assess the growth performance and feed utilization of Nile and red tilapia under different salinity conditions. The experiments were designed with salinities of 0, 15 and 25 ppt in 500 L tank. Experimental tank was divided into two parts by a fence, 30 Nile tilapia were reared in a half part of tank and 30 red tilapia were reared in another. Tilapia were acclimatized gradually to reach particular salinity concentration at a rate of 5 ppt per day until it reached the experimental salinity. The growth performance were evaluated using various indices, including weight gain (WG), specific growth rate (SGR). The study also investigated the other indices that contributed to the growth performance, including food conversion rate (FCR) and daily food intake (DFI). Results after a 55 day experiment showed that WG, SGR were highest at 0 ppt and lowest at 25 ppt for Nile tilapia. Some opposite results on red tilapia such as WG and SGR were highest at 25ppt and lowest at
0ppt. The same pattern also observed for DFI. However, no significant differences were detected for FCR indices among the treatments and the control, except significant high FCR for Nile tilapia at 25 ppt was considered. While survival rates were found significantly different between the 25 ppt treatment of O. niloticus and other treatments
of both strains. We discuss the implication of these findings to point out the advantages and disadvantages of red and Nile tilapia under culture environment and economics which help farmers deciding which strain to culture. This experiment also highlighted the needs of further study until fish reach marketable size to confirm any depression or improvement of high salinity on growth performance of Nile and red tilapias.
Keywords: Oreochromis niloticus, Oreochromis sp., salinity, feed utilization, growth performence. | en_US |
