Abstract
Nile tilapia (Oreochromis niloticus) is among the most important finfish in aquaculture, particularly in Asia. Numerous genetically improved strains of Nile tilapia have been developed and disseminated through formal and informal channels to hatcheries, many of which operate at a relatively small scale in developing countries. The primary objective of this study was to assess the extent to which molecular genetic tools can identify different and interrelated strains of Nile tilapia in Bangladesh and the Philippines, two globally significant producers. A tool was developed using a low-density panel of single-nucleotide polymorphisms (SNPs), genotyping-by-sequencing and discriminant analysis of principal components (DAPC). When applied to 2,057 samples from 205 hatcheries in Bangladesh and the Philippines, for hatcheries where the hatchery-identified strain was one of the sampled core populations used to develop the tool, hatchery-identified and DAPC-assigned hatchery-level strains were in agreement in 74.1% of cases in Bangladesh and 80.6% of cases in the Philippines. The dominant hatchery-identified and DAPC-assigned strains were GIFT, in Bangladesh, and GET-ExCEL—a composite strain partially derived from GIFT—in the Philippines.
Highlights
By weight, Nile tilapia (Oreochromis niloticus) is the most important finfish species in global aquaculture after carp (Cyprinidae) (Cai et al, 2019)
All fish sampled for this study were handled and biopsied using standard practices routinely employed in commercial tilapia operations
The three strains descended from O. mossambicus formed non-overlapping clusters in plots involving the third discriminant function
Summary
Nile tilapia (Oreochromis niloticus) is the most important finfish species in global aquaculture after carp (Cyprinidae) (Cai et al, 2019). Genetic improvement of Nile tilapia was initiated in 1988 with the creation of the “Genetically Improved Farmed Tilapia” (GIFT) strain, initially in the Philippines by ICLARM ( WorldFish) and its partners (Gupta and Acosta, 2004). Genetic improvement programs based on populations wholly descended from the original GIFT population are maintained by WorldFish (GIFT-WF, Malaysia), the Bureau of Fisheries and Aquatic Resources National Freshwater Fisheries Technology Center and its partners (GIFT FeedMix Fortified; GIFTFF, Philippines), and GenoMar (GenoMar Supreme Tilapia, Philippines), among others (Gupta and Acosta, 2004; Eknath and Hulata, 2009; Ponzoni et al, 2010; Ordoñez et al, 2014, 2017). In southeast Asia, other strains, such as Chitralada (Thailand) and “Freshwater Aquaculture Center Selected Tilapia” (FaST, Philippines), have been developed independently of GIFT (Pullin, 1988; Ordoñez et al, 2017)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
