Genetic and Morphologic Structure of Liza abu (Heckel, 1843) Populations from the Rivers Orontes, Euphrates and Tigris


Abstract: Liza abu stocks from the rivers Orontes, Euphrates and Tigris were investigated using genetic and morphometric data. Allozyme electrophoresis for genetic comparison and the truss network system for morphometric comparison were simultaneously applied to the same sample set. Highly significant morphological differences were observed between the 3 Liza abu stocks. The correct classification of individuals into their original samples for morphological characters was very high (100% of individuals). In discriminant function analyses, plotting discriminant functions revealed high isolation of the 3 stocks; the Tigris stock was very isolated from the Euphrates and Orontes stocks, and the Euphrates stock was located between the Tigris and Orontes stocks, but was closer to the Orontes stock. The pattern of phenotypic discreteness suggests a direct relationship between the extent of phenotypic divergence and geographic separation. However, genetic data do not support the detected morphometric variations. A 5 enzyme system (ICD, PGM, ME, MDH, G3PDH) composed of 6 loci was used to determine genetic comparison. All the loci were monomorphic and therefore there was no genetic divergence among the stocks.

Keywords: Liza abu, stock identification, Orontes, Euphrates, Tigris, genetic, morphologic, variation

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