Shrimp producers know it well: vibrant colors and rapid growth are distinctive features of a thriving cultivation. Therefore, supplementing the diet with pigments seems to be a suitable option to enhance color and increase the commercial value of shrimp.
Astaxanthin is traditionally used in the shrimp industry to intensify the characteristic red-pink color of shrimp (Honda et al., 2023), aiming to improve shrimp quality and obtain better prices.
This article explores the effects of astaxanthin on key aspects of shrimp health and quality, presenting the results of studies conducted with both natural and synthetic astaxanthin.
Carotenoid Pigments
Carotenoids, also known as tetraterpenoids, have attracted considerable attention due to their therapeutic attributes and immeasurable health benefits (Lim et al., 2023), growth, and stress resistance in aquatic animals.
The most common carotenoid pigments include astaxanthin, β-carotene, and canthaxanthin. Among them, astaxanthin has proven to be the predominant pigment in shrimp.
Benefits of Astaxanthin
Astaxanthin offers several benefits to aquaculture species, particularly shrimp. These include stress tolerance, disease resistance, growth performance, survival, and improvement of egg quality in fish and crustaceans (Elbahnaswy et al., 2023).
- Better Coloration: Astaxanthin deficiency leads to the blue shell syndrome in cultured shrimp (Shuangyong et al., 2022). As the astaxanthin content in the feed increased, the shrimp’s shell and muscle pigmentation also increased, translating into higher market value.
- Improved Odor: Zhang et al. (2023) investigated the effect of three forms of astaxanthin (diester, monoester, and free forms) on the aromatic characteristics and active aromatic compounds (AAC) of dried shrimp products (Litopenaeus vannamei). The study demonstrated that astaxanthin had a significant effect on AAC concentration, depending on the astaxanthin form. Astaxanthin ester had the greatest effect.
- Growth Optimization: Astaxanthin supplementation initially increased weight gain and specific growth rate, reaching its peak at a specific dietary level. Mansour et al. (2022) reported that dietary supplementation with natural astaxanthin improved the growth, feed utilization, and chemical composition of vannamei shrimp.
- Improved Fatty Acid Profile: Dietary astaxanthin altered the shrimp’s fatty acid profile, reducing saturated fat and increasing polyunsaturated n-3 fatty acids (PUFA n-3), beneficial for both shrimp health and human consumers.
- Protection Against Algal Blooms: Song et al. (2024) reported that astaxanthin has a protective effect on shrimp against microcystin, a compound produced by cyanobacterial blooms in shrimp ponds.
Impact of Astaxanthin on Shrimp Physiology
- Antioxidant Power: Astaxanthin acts as a shield against oxidative stress, as evidenced by the decrease in malondialdehyde (MDA) levels, a marker of cellular damage. This suggests overall better health and resilience of shrimp.
- Modulation of the Immune System: Astaxanthin appears to influence the shrimp’s immune system, negatively regulating the expression of certain immune genes. Lin et al. (2023) reported that incorporating astaxanthin into the shrimp’s diet increased immunological parameters and resistance against Vibrio parahaemolyticus infection, while Eldessouki et al. (2022) found similar results against V. harveyi.
- Antioxidant Activity: While overall antioxidant activity increased with astaxanthin intake, some enzymes involved in antioxidant functions showed complex responses. This highlights the importance of finding the optimal dose to achieve the desired balance.
What Is the Optimal Dose?
To determine an optimal dose of astaxanthin as a supplement in shrimp feed, it is essential to know its origin: natural or synthetic. Additionally, Honda et al. (2023) determined that the proportion of E/Z isomers affects astaxanthin accumulation in Pacific white shrimp (Litopenaeus vannamei), concluding that Z isomers of astaxanthin have higher bioavailability and/or body accumulation efficiency than (total-E)-astaxanthin in shrimp.
Here are some results of using natural and synthetic astaxanthin:
Natural Astaxanthin
Natural astaxanthin primarily comes from microalgae (Arthrospira, Schizochytrium, or Haematococcus), some yeasts (Kluyveromyces marxianus), and there has been increasing attention to using by-products of aquatic organisms for obtaining these compounds.
Mansour et al. (2022) worked with shrimp diets supplemented with astaxanthin obtained from Arthrospira platensis NIOF17/003 (GenBank accession number: MW396472) and achieved the best performance at a rate of 2.7%. Meanwhile, Shuangyong et al. (2022) worked with H. pluvialis and reported the best values for shrimp shell pigmentation and nutritional content using a rate of 20 mg kg⁻¹.
On the other hand, Liu et al. (2022) reported that the red color of vannamei shrimp body significantly improved when adding hydrolyzed Yarrowia lipolytica yeast at an optimal level of 4.64 g/kg.
Synthetic Astaxanthin
Through sophisticated analysis, the study by the team of scientists led by Qiang et al. (2023) identified the ideal level of astaxanthin in the diet to maximize the growth of black tiger shrimp (Penaeus monodon): 90 mg kg⁻¹. This valuable knowledge allows shrimp producers to adjust their feed formulations for optimal results. However, these results may also vary depending on the synthetic astaxanthin products sold on the international market.
Natural Astaxanthin vs. Synthetic Astaxanthin
There is extensive discussion about which type of astaxanthin is better. Huang et al. (2023) compared the effects of synthetic astaxanthin and natural astaxanthin (Haematococcus pluvialis and Phaffia rhodozyma) on the growth, body color, fatty acid composition, and antioxidant capacity of Penaeus monodon shrimp, and concluded the following:
- Synthetic astaxanthin has a better effect on promoting growth, improving color, and depositing n-3 PUFA in shrimp muscle.
- Natural astaxanthin (H. pluvialis) improves stress resistance generated by transportation.
Ultimately, the choice between natural and synthetic astaxanthin will depend on the prices of these products and the shrimp’s assimilation capacity. As a shrimp producer, it is best to consult with your feed supplier about the type of astaxanthin they use and evaluate the results.
Conclusion
Astaxanthin emerges as a powerful tool for shrimp producers looking to enhance color, growth, health, and potentially immune function. However, finding the optimal dose is crucial to maximize these benefits.
This article provides information on different types of astaxanthin and the main results obtained by researchers. The type of astaxanthin to use will depend on the results you expect to obtain, the prices of these products on the market and the results you obtain.
Additionally, it is important to highlight that further research is needed to fully unlock the potential of astaxanthin in shrimp aquaculture.
References
Elbahnaswy, S., Elshopakey, G.E. Recent progress in practical applications of a potential carotenoid astaxanthin in aquaculture industry: a review. Fish Physiol Biochem (2023). https://doi.org/10.1007/s10695-022-01167-0
Eldessouki, E. A., Diab, A. M., Selema, T. A. A., Sabry, N. M., Abotaleb, M. M., Khalil, R. H., … & Abdel-Tawwab, M. (2022). Dietary astaxanthin modulated the performance, gastrointestinal histology, and antioxidant and immune responses and enhanced the resistance of Litopenaeus vannamei against Vibrio harveyi infection. Aquaculture International, 30(4), 1869-1887.
Honda, M., Kamizono, S., Illijas, M. I., & Nakamura, T. (2023). Effect of feeding astaxanthin with different E/Z‐isomer ratios on astaxanthin accumulation in Pacific white shrimp Litopenaeus vannamei. European Journal of Lipid Science and Technology, 2300173.
Huang, S., Chen, Q., Zhang, M., Chen, S., Dai, J., Qian, Y., … & Han, T. (2023). Synthetic astaxanthin has better effects than natural astaxanthins on growth performance, body color and n-3 PUFA deposition in black tiger prawn (Penaeus monodon). Aquaculture Reports, 33, 101816.
Lim, K. C., Yusoff, F. M., Karim, M., & Natrah, F. M. (2023). Carotenoids modulate stress tolerance and immune responses in aquatic animals. Reviews in Aquaculture, 15(2), 872-894.
Lin, Y. J., Chang, J. J., Huang, H. T., Lee, C. P., Hu, Y. F., Wu, M. L., … & Nan, F. H. (2023). Improving red-color performance, immune response and resistance to Vibrio parahaemolyticus on white shrimp Penaeus vannamei by an engineered astaxanthin yeast. Scientific Reports, 13(1), 2248.
Liu, Yuechong, Lu Zheng, Bingying Xu, Gladstone Sagada, Jinzhi Zhang, and Qingjun Shao. 2022. “Effects of Diets with Varying Astaxanthin from Yarrowia lipolytica Levels on the Growth, Feed Utilization, Metabolic Enzymes Activities, Antioxidative Status and Serum Biochemical Parameters of Litopenaeus vannamei” Fishes 7, no. 6: 352. https://doi.org/10.3390/fishes7060352
Mansour, A. T., Ashour, M., Abbas, E. M., Alsaqufi, A. S., Kelany, M. S., El-Sawy, M. A., & Sharawy, Z. Z. (2022). Growth performance, immune-related and antioxidant genes expression, and gut bacterial abundance of Pacific white leg shrimp, Litopenaeus vannamei, dietary supplemented with natural astaxanthin. Frontiers in Physiology, 13, 874172.
Qiang Chen, Shuting Huang, Jieyu Dai, Congcong Wang, Songming Chen, Yuanxin Qian, Yangyang Gong, Tao Han, “Effects of Synthetic Astaxanthin on the Growth Performance, Pigmentation, Antioxidant Capacity, and Immune Response in Black Tiger Prawn (Penaeus monodon)“, Aquaculture Nutrition, vol. 2023, Article ID 6632067, 14 pages, 2023. https://doi.org/10.1155/2023/6632067
Shuangyong Zhang, Zhiqiang Chang, Wei Wang, Yubin Zheng, Jian Li, “Dietary Supplement of Microalgal Astaxanthin Extraction Improved Shell Pigmentation and Nutritional Value of Litopenaeus vannamei in an Indoor Industrial Aquaculture System“, Aquaculture Nutrition, vol. 2022, Article ID 3981246, 7 pages, 2022. https://doi.org/10.1155/2022/3981246
Song, Guolin, Yingcan Zhao, Junhao Lu, Zhe Liu, Jinqiang Quan, and Lirui Zhu. 2024. “Effects of Astaxanthin on Growth Performance, Gut Structure, and Intestinal Microorganisms of Penaeus vannamei under Microcystin-LR Stress” Animals 14, no. 1: 58. https://doi.org/10.3390/ani14010058
Zhang, Z., Zhou, Y., Ji, H., Zhang, D., Zheng, X., Sun, W., & Liu, S. 2023. Determination of astaxanthins contribution to the aroma characteristics and aroma‐active compounds of hot‐air‐dried shrimp products using sensory evaluation, E‐nose and GC‐MS. International Journal of Food Science & Technology.
