Can genetic diversity be maintained in long term mass selected populations without pedigree information? - A case study using banana shrimp Fenneropenaeus merguiensis

It was common for different microsatellite alleles or mtDNA haplotypes to have persisted in the different lines, such that the total number of haplotypes and allele types among all lines was much greater than that within given single lines, and the number of alleles among lines approximated that found in the wild. This observation, evident because many different lines were monitored, suggests that under certain circumstances (fixation and selection), more net genetic variability can be maintained over many generations of selection by keeping multiple different and independent lines rather than one large single line. Accordingly, if multiple lines are maintained, there could be some practical options to reconstitute allelic and haplotype variation without new introductions of genetically unimproved stock from the wild.