If you visit a premium seafood market, it won’t take long to realize that colour sells. For example, the deep red-orange of cooked shrimp, the bright pink of farmed salmon, or the rich golden colour of healthy tilapia. These colour characteristics aren’t just eye-catching; they’re also signals of the nutritional characteristics, freshness and the health of the animal, which all contribute to buyers’ purchase decisions.
Within intensive aquaculture, where fish and shrimp are fed artificial feeds without access to natural sources of carotenoids, supplementation is required to achieve these colours, and thus, the animal’s colour characteristics, due to biology.
The solution is beta-carotene fortification in aquaculture.
What Is Beta-Carotene and Why Does It Matter in Aquaculture?
Beta-carotene (β-carotene) is a provitamin A carotenoid, a naturally occurring orange pigment found abundantly in microalgae, phytoplankton, and plant matter. Unlike mammals, fish and shrimp cannot synthesise carotenoids de novo. Every molecule of carotenoid in a farmed fish’s tissue must come from its diet, as per Frontiers in Marine Science.
In the wild, fish and shrimp absorb β-carotene through their natural food chain from microalgae to zooplankton to prey species. In intensive aquaculture, that chain is broken. Formulated feeds without deliberate carotenoid inclusion produce pale, oxidatively stressed, immunocompromised animals and products that fail premium market standards.
Beyond pigment, β-carotene has three important functions in the biology of aquatic animal species:
- As an antioxidant: by counteracting the damaging effects of reactive oxygen species on cellular and tissue integrity in response to stressors associated with intensive farming.
- As a stimulant of immune activity: by increasing the activity levels of lysozyme and alkaline phosphatase enzymes as well as up-regulating transcription of immune genes.
- As a provitamin A source: to support the development of vision, reproduction, sex glands and to promote larval survival.
Beta-Carotene Benefits for Shrimp Growth and Pigmentation
The business case for beta-carotene supplementation in shrimp feed has already been documented; however, it continues to grow stronger. A significant research study on Litopenaeus vannamei (which make up over 70% of global shrimp production) was published in ScienceDirect and included feed trials with β-carotene at a rate of 100 to 500 mg/kg for a duration of 56 days. The most important findings were as follows:
- Shrimp fed diets containing β-carotene at inclusion levels between 300-400 mg/kg exhibited greater growth performance and/or higher survival rates than the control group.
- Between the 100 – 300 mg/kg inclusion rate, the amount of redness (value) of the shrimp shell displayed a linear increase.
- At the 300–400 mg/kg inclusion rate, β-carotene was equal to the industry standard of 200 mg/kg astaxanthin with respect to growth performance and pigmentation, but without the cost premium associated with astaxanthin.
The above finding is very important for producers because, according to the published results from ScienceDirect (2025), synthetic astaxanthin is priced between USD 250.00 to 450.00 per kg (based on purity of 10%) and will increase the cost of feed by more than 8% based upon the current recommendation of industry inclusion levels.
In summary, β-carotene provides a lower cost alternative providing the necessary growth and pigmentation for shrimp when compared with the cost of synthetic astaxanthin. Importantly, shrimp can bioconvert β-carotene into zeaxanthin, which can be converted into canthaxanthin and finally into astaxanthin through the normal enzyme conversion pathway (ScienceDirect, 2025). Thus, in addition to providing β-carotene, β-carotene is the “seed” or starter for the entire conversion of these carotenoids.
Beta-Carotene in Fish Nutrition: Tilapia and Beyond
Fish also provide equally valid proof of this. A controlled 70-day study on Nile tilapia (Oreochromis niloticus), published in the Fish & Shellfish Immunology journal, compared dietary β-carotene and dietary phycocyanin, respectively as replacement for Substituted antibiotics. Among other responses, the study found that:
- Serum biochemical parameters improved (total protein, albumin, globulin)
- Antioxidant enzyme activity increased [SOD and CAT activity]
- Gene expression-regulated innate immunity markers; and
- Digestive enzyme function (amylase and protease activity) increased in the intestinal tract.
The use of β-carotene as an antibiotic substitute (antibiotic for health growth) in aquaculture production of Nile tilapia has proven to be an efficient and supported substitute process.
In the crustacea species, a 2024 study by the Journal of the World Aquaculture Society investigated effects of β-carotene on gonad development, antioxidant status, and tissue carotenoid composition on female swimming crab (Portunus trituberculatus). Findings indicated that β-carotene supplementation had positive effects on reproductive performance and vivid orange-red coloration that had a direct relationship to market prices for the species.
Optimal Inclusion Rates: What the Research Recommends
|
Species |
Recommended β-Carotene Dose |
Key Benefit |
Source |
|
Litopenaeus vannamei (shrimp) |
300–400 mg/kg feed |
Growth, survival, shell pigmentation |
ScienceDirect, 2022 |
|
Nile tilapia |
100–200 mg/kg feed |
Immunity, antioxidant defence, growth |
Fish & Shellfish Immunology, 2021 |
|
Macrobrachium nipponense (prawn) |
100–150 mg/kg feed |
Growth metrics, immune response |
Aquaculture Nutrition, 2025 |
|
Swimming crab |
50–100 mg/kg feed |
Gonad development, tissue coloration |
JWAS, 2024 |
Processing note: β-carotene is light- and oxygen-sensitive. Microencapsulation or coating is recommended for pelleted feeds to protect bioavailability during storage and processing.
Frequently Asked Questions About Beta-Carotene in Aquaculture
Q: Will beta carotene replace astaxanthin in shrimp feeds?
Researchers have shown that 300-400 mg/kg of beta carotene is similar to 200 mg/kg of astaxanthin for growth and pigmentation in L. vannamei at a fraction of the price. It is now a validated alternative for aquaculture producers looking for a natural, affordable pigmentation solution.
Q: Will beta carotene boost fish immunity?
Yes. Researchers have shown that beta carotene stimulates the immune system of Nile tilapia, validating it as a natural immune system enhancer for aquaculture fish.
Q: What is the difference between beta carotene and astaxanthin in aquaculture?
Astaxanthin is the terminal carotenoid with the highest antioxidant activity. It is also the most expensive carotenoid. Beta carotene is a provitamin A carotenoid that fish and shrimp convert into astaxanthin and other carotenoids in their bodies. It provides similar benefits at a much lower price point.
Q: Is beta carotene safe for aquaculture fish?
Yes. Multiple studies have shown that beta carotene is safe for shrimp, tilapia, prawns, crustaceans, and other aquaculture fish at recommended inclusion levels. It is a natural carotenoid with a well-documented safety record for aquatic animals.
The Bottom Line
The use of beta-carotene as an additive to aquaculture feeds meets three major commercial needs: animal health, improving product quality, and managing costs of raw ingredients.
Beta-carotene can no longer be thought of as an optional additive or a secondary orange pigment source. Today, beta-carotene is a validated multi-functional ingredient that will enhance growth, antioxidant status, immune function, reproductive performance, and colour in farmed fish and shrimp at a price point that is available to all commercial producers operating at high levels.
In a market where the colour of a cooked shrimp defines the value of the shrimp, the accurate supplementation of carotenoids is not simply a detail, it defines the product.
