Development of microsatellite markers for the small yellow croaker Larimichthys polyactis (Sciaenidae) by cross-species amplification.

The small yellow croaker (Larimichthys polyactis) is a highly valued fish for human consumption found in the Western Pacific that was considered endangered until recently because of overfishing. We selected microsatellite markers for this species from markers developed for Miichthys miiuy, also of the family Sciaenidae. Among 43 markers polymorphic for M. miiuy, 11 were found to be polymorphic for L. polyactis. Characterization of these 11 loci was made based on 30 L. polyactis individuals collected by trawling in the Zhoushan Fishing Ground, Zhejiang Province, China. Total genomic DNA was isolated from fin clips. The number of alleles per locus ranged from 4 to 10, with a mean of 5.82, while the effective number of alleles ranged from 1.64 to 10.00, with a mean of 3.22. Observed and expected heterozygosities ranged from 0.17 to 0.72 and from 0.39 to 0.81, respectively. Significant deviation from Hardy-Weinberg equilibrium was found at four loci, after applying Bonferroni's correction. There was no significant association between any of the pairs of microsatellite loci, hence allelic variation at these loci was considered independent. These 11 polymorphic microsatellite loci will be useful for genetic diversity analysis and molecular-assisted breeding for L. polyactis.