Introduction
Several breeding programs and genetic parameters studies have assessed the heritability of production and survival traits in Penaeus monodon. Very few have investigated sensory quality traits such as flesh texture or color, and their correlation with production traits. Heritabilities related to weight in tiger shrimp are high and range between 0.39 and 0.48 (Hasan et al., 2020). To our knowledge, no genetic parameters are available for texture measurement, but high heritability of color, particularly in L. vannamei, was reported (Giang et al., 2019).
Material and Methods
A cohort of shrimp from the OSO Farming selection program was phenotyped and genotyped. One thousand animals were weighed before and after freezing, as well as after cooking. Texture measurements were obtained for each individual before and after cooking using a texturometer. Color was evaluated on the L*a*b* space through image analysis from a photo capture under standard condition. The same animals were genotyped using a SNP panel of 1500 SNPs. The pedigree was reconstructed from the genotyping data, and the heritabilities and the genetic correlations were assessed using genetic mixed models.
Results & Discussion
Results are presented in the table below (heritabilites on the diagonal, genetic correlation above diagonal). The estimated heritabilities were found to be very high for all growth traits, with genetic correlations among them close to unity, suggesting that a selection program focused on growth could be effective. Tail yield had low heritability and was poorly correlated with growth. Firmness appeared to be moderately heritable and correlated with growth parameters, implying that selection for growth would also result in the selection of animals with firmer flesh. Regarding color, redness and yellowness parameters were heritable but not correlated with other measured traits. Thus, a growth-based selection would not impact the color of raw and cooked shrimp. However, specific selection for color could be considered if a change to a different shade is desired.
Conclusion
Overall, the results of this study are extremely encouraging for OSO Farming as they confirm the effectiveness of their breeding techniques and growth selection plan. The investigation of texture and color provides valuable insights into the interactions between various parameters and opens up opportunities for future selection.
References
Giang, C. T., Knibb, W., Muu, T. T., Ninh, N. H., & Nguyen, N. H. (2019). Prospects for genetic improvement in objective measurements of body colour in Pacific Whiteleg shrimp (Litopenaeus vannamei). Journal of Marine Science and Engineering, 7(12), 460
Hasan, M. M., Tulloch, R. L., Thomson, P. C., Raadsma, H. W., & Khatkar, M. S. (2020). Meta‐analysis of genetic parameters of production traits in cultured shrimp species. Fish and Fisheries, 21(6), 1150-1174.