ISSN:
1095-8649
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
Twenty-one allozyme loci in samples of wild-caught and hatchery-reared Indian major carps from Bangladesh were analysed. Bayesian model-based clustering analysis revealed the presence of four taxa, corresponding to the three known species along with a fourth unknown taxon present in two hatchery samples. Individual admixture coefficients showed that 24% of all hatchery-reared fishes were hybrids, whereas a single hybrid was observed in the wild-caught samples. Only catla Catla catla× rohu Labeo rohita and mrigal Cirrhinus cirrhosus× rohu hybrids were observed, the vast majority of which were F1 hybrids, though five individuals represented putative backcrosses. Mitochondrial DNA analysis revealed that catla × rohu hybridization primarily involved catla males and rohu females, whereas mrigal × rohu hybrids primarily resulted from rohu males and mrigal females. Despite the high percentage of F1-hybrids in hatchery samples, reproductive barriers among species have so far precluded widespread introgression. Continued hybridization may eventually lead to a breakdown of species barriers, thereby compromising the genetic integrity of the species in the wild, and leading to production losses in aquaculture.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.0022-1112.2005.00785.x
Permalink