Comparative growth and viability of hybrids between two populations of Chinese shrimp （Fennropenaeus chinensis）

The total yield of shrimp farming industry declined after WSSV broke out. It was only at the last 20 years that production had again begun to increase1]. So far, shrimp farming industries mostly depend on capturing wild shrimps or wild post-larvae to sto…

Comparative growth and viability of hybrids between two populations of Chinese shrimp (Fennropenaeus chinensis)

Fenneropenaeus chinensis is confined to the Yellow Sea and Bohai Sea in China and the West Coast of the Korean Peninsula. Intra-and intercross populations were produced between Rushany (YP) and Korean (KN) populations. Seven traits were recorded. The heterosis of hybrids was computed and comparison between treatments was performed by ANOVA. At the fourth month after post-larvae, six indexes of growth trait and viability showed a range of heterosis, ranging from 0.514% to 14.950%. At the fifth month after post-larvae, six indexes of growth trait and viability ranged from −9.000% to 19.090%. The negative heterosis was observed in CL, HST and viability. The heterosis of KN♀×YP♂ tended generally to increase as the age of the Chinese shrimp increased while the heterosis of YP♀×KN♂ tended to decrease. The results indicated that the viability of reciprocal hybrids were not significantly different (P>0.05) from their parents during the experiment. The result of ANOVA indicated that the F1 hybrids were significantly different (P<0.05) in WST and TW at the fourth month. The multiple comparisons of LSD test indicated that the hybrids of YP♀×KN♂ were significantly different (P<0.05) from their parents in TW. The hybrids of YP♀×KN♂ were significantly different (P<0.05) from the other three combinations in WST. At the fifth months, the F1 hybrids had significant difference (P<0.05) in body weight while other traits showed no significant differences (P>0.05) from their parents. The multiple comparisons of LSD test indicated that the hybrids of KN♀×YP♂ were significantly different (P<0.05) from the KN parents in TW. The results indicate that in experimental conditions, the F₁ hybrids created from two populations of Chinese shrimp showed a certain level of heterosis for growth performance and viability. The crossing scheme may improve growth performance and viability in Chinese shrimp, but the improvement may be limited because effective crossbreeding requires the maintenance of pure, preferably inbred, lines and possibly involves specialized sire and dam lines. Therefore, the exploitation of heterosis through single crossbreeding in Chinese shrimp is of limited utility in practical commercial shrimp aquaculture in spite of the potential of significant heterosis. The crossbreeding of different populations can be applied in the establishment of base populations.