Study of genetic variation in populations of Coptodon zilliii, Oreochromis aureus, and Oreochromis niloticus in two areas South of Iraq, in Khaur Abdallah and Shatt Al-Arab Mitochondrial Cytochrome b Gene Analysis

This study has a specific goal in mind: Genetic Variation Study Within Populations of Coptodon zilliii, Oreochromis aureus, and Oreochromis niloticus, and analysed the partial Cytb gene sequence of mtDNA to determine genetic diversity among these species in the Khaur Abdallah and Shatt Al-Arab in the south of Iraq, where the mitochondrial cytochrome b gene was used.DNA was isolated from 40 specimens of the three species   collected from two different sites and examined. The gene size   for Coptodon zilliii,Oreochromis aureus, and Oreochromis niloticus was (439, 326 & 473 bp long (amplified Cytb gene)), respectively. The study found that two haplotypes in Khaur Abdallah and one in the Shatt-Al-Arab river in Coptodon zilliii populations, while was found one haplotype in Khaur Abdallah and one in the Shatt-Al-Arab in both Oreochromis aureus, and Oreochromisniloticus populations by using Software DnaSP v5.1. In each of the species Oreochromis aureus and Oreochromis niloticus, the research identified two types of unique haplotypes, one in Khaur Abdallah and the other in Shatt-Al-Arab. However, three haplotype patterns for Coptodon zilliii populations were discovered: one in the Shatt al-Arab River and two in Khaur Abdallah. Low nucleotide (π) and haplotype diversity (Hd) values were found in both Oreochromisaureus and Oreochromis niloticus populations in the Shatt Al-Arab river and Khaur Abdallah, indicating low genetic variation among populations for both species in the two regions. However, there was no diversity within the Oreochromis aureus population in both Shatt Al-Arab and Khaur Abdallah. The population of Oreochromis niloticus has the same indication. Three haplotypes for Coptodon zilliii indicate to genetic variance across populations in the Shatt Al-Arab riverand Khaur Abdallah regions, although no variety within the Coptodon zilliii species was found in the Shatt Al-Arab river. In the Khaur Abdallah district, there was little genetic diversity among them.