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Abstract

Three major carps namely; Labeo rohita, Catla catla, Cirrhinus mrigala are commercially important aquaculture freshwater fish species of Pakistan. Ascertaining the pure species status of major carps is essential for their appropriate management and conservation. The use of microsatellites DNA markers and Bayesian models based statistical methods have considerably improved the estimation of admixture analyses at individual level. In the present study, a set of twelve heterologus microsatellite markers were employed to assess the extent of potential hybridization in stocks of major carps collected from Ravi River basin. The methods, Structure assignation and Newhybrids status determination statistical analyses were used to determine the status of pure and hybrid individuals. Multidimensional and model-based Bayesian assignment analyses consistently delineated the presence of individuals having mixed-ancestry genome and detected different levels of hybridization between major carps fish species. The clustering analyses showed high efficiency in the detection of F 1 hybrids as well as potential backcross specimens. For the first time, the incidence of natural hybridization between major carp fish species was detected on genetic basis, at frequency rates reaching about 7.77% in Ravi River basin Punjab, Pakistan. The Bayesian model statistical analyses proved to be robust tools in discriminating pure species and hybrid specimens.

Transferability of heterologous microsatellite primers in Leiarius marmoratus

“…Genetic studies have recently shown that heterologous microsatellite markers are able to differentiate hybrid species from pure species as assessed by Parveen, Abbas, Afzal & Hussain (2018) in a study with three species of carp (Labeo rohita, Catla catla, and Cirrhinus mrigala) and Esquer-Garrigos et al (2015) in Andean pupfishes (Orestias agassizii and O. luteus). This is very important when dealing with species of the Pimelodidae family, since the intergenic hybridization of catfish, including L. marmoratus and P. reticulatum, is common in South American fish farms (Hashimoto, Prado, Foresti & Porto-Foresti, 2016), and may present risks of genetic contamination of natural stocks by accidental releases, leading to genetic introgression (Hashimoto, Senhorini, Foresti, Martínez, & Porto-Foresti, 2014).…”