Allozyme-based analysis of genetic variation among 3 cultured stocks of snakehead fish, Channa striata (BLOCH, 1797)

Abstract

Genetic variation based on allozyme markers was comparatively analysed among three cultured stocks (Suphan Buri, Nakhon Ratchasima and Buri Ram) of snakehead fish, Channa striata (BLOCH, 1797). On the 22 allozyme loci screened, 7 polymorphic loci were found. Genetic variabilities including per locus averages of number of averaged alleles (Na), effective number of alleles (Ae), allelic richness (R), observed heterozygosity (Ho) and expected heterozygosity (He) were respectively as Na = 1.242 (1.136 – 1.318), Ae = 1.032 (1.019 – 1.049), R = 1.235 (1.136 – 1.308), Ho = 0.024 (0.012 – 0.037) and He = 0.026 (0.017 – 0.038). Non-significant deviations from Hardy-Weinberg equilibrium (P_HWE>0.05) were shown in all stocks when the analyses were done over all the 22 loci. The amount of genetic variation of the 3 cultured stocks, informed by Na, Ho and He, were in the same level as those appeared in wild stocks. Genetic differentiation analyses showed non-significant differences (P>0.02) both among and in each pair of the 3 cultured stocks and between of stocks. All the results suggested that the 3 cultured stocks had equal genetic potential which was enough for being a broodstock population of aquaculture and selective breeding.

Combining the genetic information resulting from this study and the growth performance from the previous study, the suggestion is that the Buri Ram stock is the most suitable for the Buri Ram Aquaculture Genetics Research and Development Center to use for a further selective breeding program of snakehead fish, in order to have the best and most suitable strain for the Norhteast region aquaculture.