Comparative population genetic structure of redbelly tilapia (Coptodon zillii (Gervais, 1848)) from three different aquatic habitats in Egypt

Abstract

Recently, tilapia have become increasingly important in aquaculture and fisheries worldwide. They are one of the major protein sources in many African countries and are helping to combat malnutrition. Therefore, maintenance and conservation genetics of wild populations of tilapia are of great significance. In this study, we report the population genetic structure and genetic diversity of the redbelly tilapia (Coptodon zillii) in three different Egyptian aquatic environments: brackish (Lake Idku), marine (Al‐Max Bay), and freshwater (Lake Nasser). The habitat differences, environmental factors, and harvesting pressures are the main characteristics of the sampling sites. Three mitochondrial DNA markers (COI: cytochrome oxidase subunit I; the D‐loop; CYTB: cytochrome b) were used to assess population structure differences among the three populations. The population at Lake Nasser presented the highest genetic diversity (H d = 0.8116, H = 6), and the marine population of Al‐Max Bay the lowest (H d = 0.2391, H = 4) of the combined sequences. In addition, the phylogenetic haplotype network showed private haplotypes in each environmental habitat. Results presented here will be useful in aquaculture to introduce the appropriate broodstock for future aquaculture strategies of C. zillii. In addition, evidence of population structure may contribute to the management of tilapia fisheries in Egyptian waters.

Monitoring the genetic effects of broodstock enhancement of silver carp (Hypophthalmichthys molitrix) in middle Yangtze River based oncytbgene and D-loop sequences

“…Generally speaking, the number of distinct haplotypes, haplotype diversity (Hd) and nucleotide diversity (Pi) represent the standard indices of genetic diversity. In this study, the genetic variability of the mtDNA cytb and D-loop of the four silver carp populations was characterized with high haplotype diversity and low nucleotide diversity, which was often observed in other animals like Baylisascaris schroederi (Zhou et al 2013), Coptodon zillii (Soliman et al 2017) and Hungarian Gidran horse (Nikolett et al 2016). After 6 years of release, both Hd values and Pi values obtained with two markers changed, but the results of the t-test confirmed that the change was not statistically significant.…”

Genetic Diversity and Population Differentiation of Kashgarian Loach (Triplophysa yarkandensis) in Xinjiang Tarim River Basin

“…Actually, aquaculture activities in the Tarim river basin are less developed due to the special environment (high salinity and sediment concentration) [ 33 , 34 ], and the natural populations of T. yarkandensis were actually less interfered by agricultural activities. In this context, although anthropogenic factors could affect the genetic structure and differentiation of fish populations [ 35 , 36 ], especially in some economic fish species widely cultured in aquaculture [ 14 , 37 ], we noted that the genetic exchange among most populations mediated by anthropogenic factors was limited in the Tarim River basin. Here, we suggest that the T. yarkandensis populations should be monitored in the long term to avoid significant reductions in abundance due to the genetic characterizations, including the high levels of genetic variation originating from among-population variation and the small effective population size.…”

Genetic Diversity and Population Structure of Hemiculter leucisculus (Basilesky, 1855) in Xinjiang Tarim River

“…Combined with the results of NJ tree and PCA, the individuals from TTMH showed differences and had a bigger geographic distance than the others. The genetic differentiation pattern of fish is usually consistent with the water system pattern of distribution [ 32 , 33 ]. It could be explained by the reason that due to the large-scale diversion and interception of water in the middle and upper reaches of the Tarim River, the lower reaches of Tarim River have been cut off [ 28 , 34 , 35 ].…”