Growth, length-weight relationship, and condition factor of NIFI (Oreochromis sp.) and Srikandi Tilapia (Oreochromis aureus x niloticus) at the grow-out stage in the high salinity brackishwater ponds
Tilapia strain of NIFI (Oreochromis sp.) and Srikandi (Oreochromis aureus x niloticus) are superior strain of tilapia that able to grow well in brackish water ponds. However, an increasing water salinity might have an impact on a series adaptation process on fish that leads to various morphological changes. This study aimed to analyze the growth and length-weight relationship of both tilapia strain in brackishwater pond with salinity of 25-30 ppt. Research was conducted in brackishwater pond in Losari, Brebes Regency. Fish were reared in 5x5x1 m3 hapas installed in the pond for four months. At the end of experiment period, body length and weight measurement were carried out for 26 males and 34 females of NIFI strain and 31 males and 28 females of Srikandi strain. The result showed that the highest growth rate was shown by Srikandi strain and the highest length was shown by NIFI. Positive allometric growth was found in the Srikandi females, while Srikandi males as well as NIFI tilapia males and females showed a negative allometric growth. Length-weight relationship on males and females of NIFI strain followed the formula of W = 0.0583L2,632 and W = 0.0452L2,665, respectively. Whereas, on males and females of Srikandi strain followed the formula of W = 0.0358L2,8545 and W = 0.0287L3,1580, respectively. There was a strong correlation between length and weight of fish from both strains with the R2 value ranged between 0.80 – 0.87. Condition factor of males and females of NIFI were 1.853 and 2.009, while Srikandi tilapia males and females were 2.308 and 2.665, respectively. Red NIFI and Srikandi tilapia are able to adapt in a high salinity level of brackish water pond.