The review, led by Faisal Rashid and colleagues at Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, synthesizes evidence from feeding trials conducted across finfish and crustacean species, from rainbow trout and Atlantic salmon to Nile tilapia, Jian carp, European sea bass and Pacific white shrimp. The authors assessed final body weight, specific growth rate, feed conversion ratio, feed intake, feed efficiency, survival and apparent digestibility coefficients, always benchmarked against conventional fishmeal diets. Their conclusion is cautiously optimistic: black soldier fly larvae meal can replace a substantial share of fishmeal in many species, but the response depends heavily on the target species, its life stage, the processing method applied to the larvae and the inclusion level in the diet.

Part of the appeal lies in the larvae’s raw potential. On a dry-matter basis, black soldier fly larvae typically contain 32 to 53 percent crude protein and 18 to 33 percent lipid, figures that rival fishmeal’s protein content. Yet the composition is anything but fixed. Protein, lipid, fiber, ash, amino acid and fatty acid profiles all shift with the rearing substrate, the developmental stage at harvest, the drying method and the degree of defatting. Published analyses show crude protein values ranging from roughly 26 percent to 47 percent and crude lipid from 18 to nearly 48 percent, which is why the authors stress that values must always be compared on the same analytical basis, whether dry-matter or as-fed. Defatting, notably, lowers lipid content and raises the relative protein concentration, making defatted meal the preferred ingredient for high-inclusion diets.

The rearing substrate itself is a biochemical dial that farmers can turn. Studies cited in the review show that prepupae raised on different vegetable by-products contained 67 to 89 milligrams of leucine per gram of protein and 47 to 72 milligrams of lysine per gram of protein, while larvae fed kitchen waste accumulated more proline, tyrosine and phenylalanine than those reared on chicken manure or brewer’s spent grain. Substrate manipulation can even reshape the fatty acid profile: adding brown seaweed to the feeding medium increased the omega-3 fatty acid EPA in larval tissue, although seaweed inclusion above 50 percent reduced larval growth and total lipid content. Saturated fatty acids, dominated by lauric acid, remain the major component of larval fat, which raises both formulation challenges and, intriguingly, functional opportunities.

Those opportunities extend beyond simple nutrition. The larvae contain chitin from their exoskeleton, lauric acid, antimicrobial peptides and other biologically active compounds that can influence antioxidant status, innate immunity and gut microbial communities. In European sea bass, replacing 25 to 50 percent of fishmeal protein with larvae meal improved antioxidant and non-specific immune responses and increased resistance to challenge with the pathogen Vibrio alginolyticus. In Pacific white shrimp, a diet replacing 10 percent of fishmeal protein improved survival after a Vibrio parahaemolyticus challenge, although a 30 percent replacement reduced growth and damaged intestinal structure. In Atlantic salmon, 10 percent dietary inclusion under farm-like conditions produced positive changes in skin mucosal, hematological and gene expression profiles without compromising growth or welfare.

The economics look increasingly persuasive as well. In European sea bass, replacing up to half of the fishmeal protein with defatted larvae meal maintained growth while cutting estimated feed costs by about 15.6 percent. In Siberian sturgeon, diets containing 10 to 15 percent full-fat larvae meal delivered the best economic returns, and under earthen-pond conditions in Kenya, replacing 25 to 75 percent of fishmeal maintained Nile tilapia growth while improving profit-related indicators. The review cautions that simply removing fishmeal does not automatically make a diet cheaper, because commercially produced insect meal can sometimes cost more than traditional protein sources, and economic analyses should track feed cost per unit of weight gain and sensitivity to insect meal prices rather than cost per kilogram of feed alone.

Beneath the nutrition lies a broader environmental story. Black soldier flies are voracious saprophagous feeders, originally native to South America and now distributed across the tropics, capable of converting fruit and vegetable waste, manure and municipal organic refuse into protein- and lipid-rich biomass. The residual material left behind can serve as organic fertilizer or soil amendment, and larval fat can even be processed into biodiesel. With roughly 1.05 billion tonnes of food wasted at the retail, food-service and household levels in 2022, nearly 19 percent of the food available to consumers, insect bioconversion offers a dual benefit: it diverts waste from landfills, generates lower greenhouse gas emissions than conventional disposal, degrades antibiotics in contaminated substrates and reduces pathogen loads, all while producing a feed ingredient.

Scaling that vision, however, demands mastering the fly’s biology. The species undergoes complete metamorphosis through egg, larva, pupa and adult stages, and its reproduction is acutely sensitive to light, temperature and humidity. Mating requires strong light and sufficient space, with quartz-iodine lamps supporting indoor mating, though at lower rates than natural sunlight, and LED lighting now recommended for small-scale rearing on grounds of energy efficiency. Egg hatching peaks at 30 to 35 degrees Celsius, survival from young larvae to adulthood ranges from 74 to 97 percent at 27 to 30 degrees Celsius but collapses to 0.1 percent at 36 degrees, and relative humidity of at least 50 percent is required to maintain colonies. These narrow environmental windows mean that commercial larval production carries real energy costs, particularly for heating and drying.

That energy question is central to the review’s most sobering assessment. Life-cycle assessment studies show that the environmental performance of larvae meal depends strongly on the rearing substrate, the energy used for heating and drying, transport distances and how impacts are allocated among larval meal, oil and residual material. Energy-intensive processing or purpose-grown substrates can offset much of the benefit gained from waste valorization, and the authors argue that only transparent assessments with clearly defined system boundaries and region-specific energy data can determine whether larvae meal genuinely outperforms fishmeal or plant proteins. Safety also demands vigilance: while dioxins, PCBs, PAHs, pesticides and mycotoxins generally do not accumulate in the larvae, heavy metals such as cadmium and lead can bioaccumulate, occasionally exceeding permitted feed levels, and heavy metal concentrations intensify in the residual fraction, limiting its use as fertilizer.

Even so, the species-level evidence suggests real headroom. Feeding trials show no clear harm from replacing more than 50 percent of fishmeal in general, and some species, including Atlantic salmon, Jian carp and Nile tilapia, have been raised successfully on diets with high or even complete fishmeal replacement, with Nile tilapia tolerating 100 percent replacement without adverse effects on growth, survival or blood parameters, and even showing enhanced skin-mucus lysozyme activity. Other species, notably turbot and shrimp, respond poorly beyond modest inclusion levels, likely because of the larvae’s chitin and fat content and their limited capacity to digest insect-based feeds. Fermentation and other processing techniques can reduce chitin, amino acid supplements can correct the meal’s relative deficiency in certain essential amino acids, and regulatory frameworks, still underdeveloped in many regions, are gradually catching up. The review’s bottom line is that the right inclusion level must be established species by species, using consistently processed larvae products and properly balanced diets, and that only through integrated assessment of nutrition, economics, safety and verified life-cycle impacts can black soldier fly larvae meal earn its place as the sustainable backbone of a rapidly growing aquaculture industry.

Subject of Research: Use of black soldier fly larvae meal as a fishmeal alternative in aquafeeds for sustainable aquaculture

Article Title: Black soldier fly (Hermetia illucens) larvae meal in aquafeed for a sustainable aquaculture industry: a review

Article References: Saba, K., Iqbal, G., Aakila, Mushtaq, S., Asimi, O., & Rashid, F. (2026). Black soldier fly (Hermetia illucens) larvae meal in aquafeed for a sustainable aquaculture industry: a review. Frontiers in Aquaculture, 5, Article 1862744. https://doi.org/10.3389/faquc.2026.1862744

Image Credits: AI Generated

DOI: 10.3389/faquc.2026.1862744

Keywords: aquaculture, aquafeed, black soldier fly, Hermetia illucens, fishmeal replacement, insect protein, sustainable feed, fish nutrition, Pacific white shrimp, Atlantic salmon, life-cycle assessment, food waste valorization

The stakes are considerable. Shrimp aquaculture has become one of the fastest-growing food production sectors on the planet, and India sits at its center. The country ranks third in global aquaculture output after China and Indonesia, accounting for 7.70 percent of world production, and its sector has posted double-digit annual growth exceeding 10 percent over the past decade. Yet the industry’s Achilles heel lies at the very start of the production line: hatcheries that supply healthy seed stock. Poor quality larvae during the initial stages constrain survival, growth, and ultimately the productivity of entire farming operations downstream.

Conventional shrimp hatcheries solve their water quality problems the old-fashioned way—by flushing. Large volumes of water are exchanged continuously to keep toxic nitrogenous wastes in check, a strategy that carries heavy costs in pumping, collection, filtration, and disinfection, while also creating pathways for disease and discharging nutrient-rich effluent into the environment. Biofloc technology, or BFT, offers a fundamentally different approach. Instead of removing nitrogenous waste, the system recruits communities of heterotrophic bacteria to convert it into microbial biomass. By manipulating the carbon-to-nitrogen ratio in the water, farmers encourage these bacteria to proliferate, forming dense suspended aggregates—the flocs—that shrimp can graze on as a natural, continuously available food source.

The catch is that bacteria need carbon to do this work, and not all carbon sources are created equal. Simple sugars such as molasses, glucose, and fructose are rapidly degraded, while complex materials like rice bran and cellulose break down slowly. The choice of carbohydrate shapes how quickly flocs form, how efficiently nutrients are assimilated, and how stable the microbial community remains. Despite the technology’s successful adoption across broodstock, nursery, and grow-out phases of shrimp production, information on its effectiveness during the delicate larval and postlarval stages of Penaeus vannamei has remained scarce—precisely the gap the Indian team set out to fill.

The experiment took place at the BKMN shrimp hatchery in Undavalli, in the Guntur district of Andhra Pradesh. The researchers used eight circular high-density polyethylene tanks of 1000 liters capacity, each with a working volume of 800 liters, meticulously cleaned and treated with bleaching powder before use. Specific pathogen-free shrimp nauplii, confirmed disease-free by PCR testing, were stocked at an extraordinarily high density of 100 larvae per liter—80,000 animals per tank—at the mysis-1 stage. Three biofloc treatments were established at a fixed carbon-to-nitrogen ratio of 15:1, using fructose, lactose, or dextrose as the carbon source, alongside a control with no carbohydrate addition. The trial ran for 13 days, until the larvae reached postlarval stage 10, with zero water exchange throughout.

Building the flocs required careful staging. Following the protocol pioneered by aquaculture researcher Yoram Avnimelech, the team introduced nitrogen on the first day by adding 1.5 grams of ammonium chloride, then added carbon sources on days three and five at 5.62 grams, doubling the dose to 11.25 grams on day seven. The water’s transformation from clear and transparent to light brown signaled that floc formation was underway. Larvae were fed a commercial microencapsulated diet with a minimum protein content of 52 percent, distributed across six daily feedings, with quantities adjusted to floc volume at each developmental stage.

The water chemistry results told a clear story. Temperature remained in the optimal 27 to 29 degrees Celsius range, and dissolved oxygen stayed between 5.30 and 6.24 milligrams per liter, comfortably above the lethal threshold of 1.0 ppm reported for the species. More striking were the differences in nitrogen compounds. Total ammonia nitrogen in the biofloc tanks ranged from 0.69 to 0.78 milligrams per liter, significantly lower than the control’s 1.07. Un-ionized ammonia, which is highly toxic to shrimp, measured just 0.12 milligrams per liter in the biofloc treatments against 0.36 in the control. Nitrite, which damages the circulatory and immune systems of aquatic animals, was a mere 0.06 milligrams per liter in the biofloc systems compared with 1.53 in the control—well above the 1.0 milligram per liter considered optimal for successful culture. Nitrate and alkalinity also differed significantly among treatments, with biofloc alkalinity of roughly 127 to 128 milligrams per liter far exceeding the control’s 91.38.

Survival data sealed the case for dextrose. At postlarval stage 1, dextrose-fed tanks achieved 93 percent survival, followed by fructose at 88.67 percent, lactose at 86.33 percent, and the control at 79.33 percent. By postlarval stages 5 and 10, the gap widened: 90.67 percent for dextrose, 85.67 percent for fructose, 78.33 percent for lactose, and a sobering 66.67 percent for the control. The researchers attribute dextrose’s advantage to its chemistry. As a monosaccharide derived from simple starch, it is readily broken down by bacteria, driving robust floc formation—the dextrose treatment produced the greatest floc volume at 1.62 milliliters per liter, compared with 1.12 for fructose and just 0.84 for lactose, a disaccharide that microbes decompose more slowly.

The broader implications extend beyond a single hatchery in coastal India. Every biofloc treatment group surpassed the 70 percent survival benchmark considered appropriate for the species and for experimental hatcheries, and the overall biofloc survival range of 71 to 86 percent dwarfed the control’s 53 percent. Because the systems operated with zero water exchange, they promise reduced water costs, enhanced biosecurity against pathogens, and a smaller environmental footprint—attributes that matter enormously as the industry confronts disease outbreaks and tightening environmental regulations. The flocs themselves add nutritional value, offering shrimp a supplementary microbial food source alongside formulated feeds.

For an industry that contributes roughly 1.24 percent to India’s gross value added and more than 7.28 percent to agricultural GVA, with exports of 12.22 million tonnes valued at 1.42 billion US dollars in 2023, even incremental gains in hatchery survival compound into substantial economic returns. The study’s conclusion is pragmatic: fertilization with dextrose at a 15:1 carbon-to-nitrogen ratio can efficiently maintain a shrimp hatchery system without any water exchange. As biofloc technology continues its march from experimental tanks to commercial operations worldwide, this finding suggests that one of the most consequential decisions a hatchery manager makes may be as simple as choosing the right sugar.

Subject of Research: Biofloc technology with different carbon sources for Pacific white shrimp hatchery production

Article Title: Hatchery performance of Pacific white shrimp, Penaeus vannamei in Biofloc technology by using different carbon sources

Article References: Suneetha, K., Padmavathi, P., & Chatla, D. (2024). Hatchery performance of Pacific white shrimp, Penaeus vannamei in Biofloc technology by using different carbon sources. Blue Biotechnology, 1(1), Article 13. https://doi.org/10.1186/s44315-024-00016-4

Image Credits: AI Generated

DOI: 10.1186/s44315-024-00016-4

Keywords: biofloc technology, Pacific white shrimp, Penaeus vannamei, aquaculture, dextrose, carbon source, water quality, larval survival, hatchery, zero water exchange, carbon-nitrogen ratio, sustainable aquaculture