Probiotics For Fish | Probiotics In Aquaculture For Fish Farming

Probiotics for fish in aquaculture are a group of beneficial microorganisms that positively contribute to the immunity and productivity of aquatic organisms. It improves the gut microbial balance of aquatic organisms and provides a wide spectrum of benefits.

Probiotics for fish may also act as natural biological soil and water conditioners (Depending upon their enzymatic machinery) and help clean the waters where fish reside.

The various species of microorganisms used as probiotics in aquaculture are Bacillus sp., Lactobacillus sp., Bifidobacterium, Enterococcus sp., Saccharomyces, etc.

Probiotics in aquaculture are a group of bacteria that benefit aquatic organisms by improving the gut microflora of aquatic organisms by replacing harmful microbes with healthy beneficial bacteria that colonise the gut.

They form a natural symbiotic relationship with their host. Probiotics are provided as an aquatic feed that can act as the source of nutrients and enzymes that can help in better digestion of food. Probiotics for biofloc fish farming improve the immune system of aquatic organisms by activating non-specific immune systems boosting the defence against many diseases.

Probiotics for fish compete with the pathogens in the host gut limiting their access to food and colonization. They also secrete antibiotics and other antibacterial metabolites that help in reducing the pathogen population, which helps in protecting the host organisms from various infectious diseases.

Probiotics for fish secrete various useful enzymes such as amylases, proteases, and lipases that help improve digestion and nutrient uptake of the host organism.

Probiotics in aquaculture are known for their wide variety of benefits, like enhancing the immunity of host organisms, improving their digestive capabilities, improving the gut flora of host organisms, and eliminating disease-causing pathogens.

Biofloc technology utilises bacteria for the two aspects of improving water quality and as a source of feed for aquatic organisms.

Apart from enhancing the health and quality of aquatic organisms, probiotics for fish also improve water quality in aquaculture systems. During the course of fish growth, there is a rise in the concentration of nitrogen, organic matter, and other nutrients in the tank.

Probiotics in fish farming consume organic material, and with added carbon-rich nutrients, they help maintain the C: N ratio and reduce nitrogen concentration. Maintenance of nutrient concentration below a threshold limit helps in preventing harmful algal growth inside the tank.

These probiotic microbes form bioflocs inside the tank and entrap suspended solid organic material, thus reducing the water turbidity and keeping the water tank clean. Penetration of sunlight through the waters also helps in keeping the pathogen load in the waters in check.

Fish or shrimps spend the larval phase of their life in hatcheries which is the most critical phase of their growth cycle. The larvae have an underdeveloped digestive system and gut microflora, and they lack a fully functional immune system and osmotic system.

In these conditions, it becomes very difficult to cope with any kind of physical, chemical, or environmental stress. The use of probiotics for fish hatcheries helps the larval stages tackle such stress conditions by improving immune response, maintaining water quality, and reducing disease-causing pathogens from the system.

Probiotics for fish secrete specific antibacterial metabolites against pathogens, reducing their population by natural competition. The probiotics compete for food, and their adhesion to the intestinal wall disallows pathogens to get a nutrient supply or colonization in the gut of the host.

An enhanced immunity always helps in handling disease-causing pathogens, and probiotics stimulate the innate immunity of aquatic organisms eliciting an immediate response to any kind of disease.

Probiotics for fish colonize the intestinal gut of aquatic organisms and secrete several beneficial enzymes like amylases, proteases, and lipases. These enzymes improve the digesting capacity of the host organism.

These enzymes help in the efficient breakdown of feed and better retention of nutrients in host organisms, ensuring a better feed conversion ratio. This, in turn, improves immunity, productivity, and, therefore, profits. Probiotics for fish have a multi-faceted impact on the economics of aquaculture.

In most aquaculture systems, hatcheries apply high-density seeding to obtain a high output. This high-density seeding induces stress in larvae and fishlings. Such stressful conditions can lead to various psychological and behavioral changes in aquatic animals, feed utilization, hormonal changes, and immunosuppression.

The use of water probiotics in aquaculture as a food supplement helps fish cope up with such stress conditions and enhances their immune system preventing disease and reducing mortalities in the hatchery.

Biofloc technology is an environment-friendly method of aquaculture where aquatic organisms are grown in an enclosed system with enough supply of nutrients and oxygen. This technology is highly dependent on microorganisms for the maintenance of water quality by utilizing nitrogen produced during fish culture and the formation of microbial flocs that can be used as protein feed by fish and shrimps.

It is environmentally sustainable technology as it prevents the discharge of water containing excessive nutrients or pathogens into a natural water body.

Biofloc technology allows the reuse of water as water quality in the tank is maintained by bacterial flocs utilizing the available nitrogen to grow and reproduce and form flocs. This bears a huge economic benefit as water usage is a costly affair.

Rearing of aquatic organisms with biofloc technology results in improved size and weight of the aquatic organisms giving high returns for the products. Thirdly, prevention of disease prevents high losses due to deaths or ill-grown aquatic organisms.

It also reduces the requirement for antibiotics, thereby increasing savings. It is reported that approximately 25 to 30% of the fish feed can be bioflocs formed in the tanks, which reduces the need for a supply of fish feed as well.

Biofloc technology offers a solution to environmental concerns caused by aquaculture. The microorganisms in the enclosed system consume nitrogen accumulated in the tank along with the carbon source added to the system to grow and replicate.

This allows the reuse of water from the tank and eliminates the water exchange in order to balance the nitrogen levels of the tank. The reuse of water in this technology reduces the load on fresh water and the wastage of large volumes of water due to water exchange.

The water exchange in traditional aquaculture leads to the discharge of high concentrations of nitrogen in water bodies leading to eutrophication. Not just this, the reduced usage of antibiotics reduces the pollution levels contributed by these chemicals to our water resources as well.

The basic requirements for algae growth are sunlight, nitrogen, and phosphorus as a nutrient source. In an aquaculture system, the used water is released into rivers, ponds, lakes, and other water bodies.

This adds the organic matter, nutrient concentration, and pathogens to these water bodies making ideal conditions for algal growth leading to severe eutrophication. The Biofloc technology allows the reuse of water and minimum water discharge.

Thus, limiting the introduction of nutrients to natural water bodies prevents algal blooms in these water bodies. Probiotics for biofloc fish farming used in biofloc technology, therefore, can have a lasting impact on preventing algal blooms.