Comparative analysis of fecundity of 5 specialized strains of shrimp Macrobrachium rosenbergii

Abstract:

In order to investigate the breeding performance of Macrobrachium rosenbergii, this experiment was conducted by measuring 5 specialized strains of shrimp Macrobrachium rosenbergii (A, B, C, D, E) of the three consecutive spawning unit weight of fecundity (F_W) ovarian development cycle (C_O), fertilized egg diameter (D_E), vitellogenin (VTG) content, and cathepsin D (CTSD) activity index, and comparative analysis of 5 selection strains of fertility was made, with a view to screening the high fecundity strains of Macrobrachium rosenbergii. The results showed that the absolute fecundity (F), F_W and body weight were positively correlated (P<0.05), F and F_W were also significantly positively correlated (P<0.01). The average value of F_W of the continuous thrice spawning of the 5 selected strains was (1.96-2.30)×10³ eggs/g, the differences between the strains were significant (P<0.05).The F_W of B and D were 2.26×10³ eggs/g and 2.30×10³ eggs/g respectively. The average range of VTG content and CTSD activity in the 5 selected strains were 3.48-5.80 μg/g, 271.81-320.82 U/g, and there was significant difference among the strains (P<0.05),while the highest content of VTG in fertilized eggs was B (5.80 μg/g), the highest CTSD activity was D (320.82 U/g), the second was B (303.09 U/g), and there was no difference between them (P>0.05). The range of Co was 18.8-23.8 d, second time larger than the first (2-8 d), there was no difference (P>0.05) between each strain,which were all significantly lower than those in the control group (P<0.05). The mean value range of D_E was 542.3-552.0 nm, there is no difference among strains, and the average egg diameters of B and D were larger, 551.7 nm and 552.0 nm, respectively. It can be confirmed that among 5 specialized strains of Macrobrachium rosenbergii, the fecundity of B and D is the strongest, A is weak, C and E is the weakest, which can provide basis for breeding of specialized strains of shrimp Macrobrachium rosenbergii.