The Importance of HUFAs in Betta Foods
HUFA stands for “Highly Unsaturated Fatty Acids” and is a term which is very important as it pertains to aquaculture and farming of bettas in their diets. In this article I will go into some details and explain the more or less the following info:
What do we mean when we say HUFA – Long, energy-packed chains of carbon and hydrogen that build fats in bettas.
Why we find HUFA are an important component of the betta’s diet – They act as a fish anti-freeze, are precursors to very important biological molecules, and are a very efficient and needed means of moving high-quality energy up the food chain to your betta resulting in increased rates of growth and reproduction in your betta stocks.
What foods we found that will provide HUFA – Dried foods such as Cyclops, Mysis, Plankton, Crickets, mealworms and others contain HUFA. A lot of studies in salmon and tilapia have shown fish benefit most from frequent feedings of two to three or more different dried foods each week or a pellet blended to meet this requirement.
What really are Fatty Acids? Well glad you asked, fatty acids (FA) are building blocks of fats. They consist of a hydrocarbon chain with a polar, carboxyl functional group (COOH) on one end. The carboxyl group is what makes the molecule an acid and at biological pH values is found in an ionized form where the hydrogen of the hydroxyl (OH) group is missing leaving a negatively charged oxygen atom. This polar end of the fatty acid is hydrophilic, or attracted to water. The carbon-hydrogen bonds of the hydrocarbon chain are nonpolar and so are hydrophobic and thus, excluded by water. The hydrophobic interactions of the hydrocarbon chains of fats explain the separation that can be seen in such everyday items as salad dressing where the oil separates from the water. The hydrocarbon tails pack together on the inside of the oil droplets while the polar carboxyl groups associate with the water. Environment and/or trophic level are major factors, with freshwater/diadromous species generally requiring C18 polyunsaturated fatty acids (PUFA) whereas marine fish have a strict requirement for long‐chain PUFA, eicosapentaenoic, docosahexaenoic and arachidonic acids. Other than marine fish larvae, defining precise quantitative or semi‐quantitative EFA requirements in fish have received less attention in recent years. However, the changes to feed formulations being forced upon the aquaculture industry by the pressing need for sustainable development, namely the replacement of marine fish meal and oils with plant‐derived products, have reintroduced EFA into the research agenda.
The character of the hydrocarbon chain will determine whether a fatty acid is considered “saturated” or “unsaturated”. Saturated FA have the maximal number of hydrogen atoms bonded to each carbon in the chain. Such chains contain carbon to carbon single bonds.
A class of enzymes called desaturases can convert saturated FA to unsaturated FA, which have one or more carbon to carbon double bonds. Carbon atoms participating in a double bond have fewer than the maximal number of hydrogen atoms bonded to them. The double bonds are formed as the desaturase enzyme removes one hydrogen atom from each carbon. The positions of the double bonds are designated by their location relative to the last carbon in the chain using the symbol ω (the last letter in the Greek alphabet, omega). Of particular importance to nutrition are the ω3 FA, where the double bond begins 3 carbon atoms from the end of the chain. The introduction of a double bond to a hydrocarbon chain puts a “kink” in its structure. The kinks are commonly shaped in what is known as the “cis” configuration. When the hydrocarbon tails of FA associate together in avoidance of water, kinks will prevent them from packing too closely and help to lower the freezing point (keeping the FA fluid at lower temperatures).
Fats, also known as lipids, play a very important role in animal physiology. They are the major component of biological membranes which envelop every cell of an animal’s body. The presence of certain types of lipids in specific proportions is essential to life. While this article will not discuss the importance and functions of biological membranes, it is important to point out that membranes have very complex functions, specific to each cell type. What is most important to understand is that membranes are NOT solid, static structures. They are fluid and formed from the hydrophobic interactions of the lipids with each other rather than with water (as discussed earlier-think of the droplets of oil formed in salad dressing). Cell membranes are actually lipid bi-layers. One can picture this as two concentric circles of lipid molecules where the polar portions associate with the water on the inside and outside of the cell while the hydrophobic tails of each layer point towards each other away from the water on either side of the membrane. The lipids, along with proteins and other components of the membrane, are all considered a part of a “Fluid Mosaic”. The “fluid” nature allows movement of the membrane components within the plane of the membrane. The extent of a specific membrane’s fluidity (and therefore its ability to perform specific functions) is determined in part by its lipid composition-the ratio of saturated to unsaturated lipids, concentrations of specific FA, etc. The FA of a membrane will have marked effects on the temperature at which the membrane freezes (becomes solid) and no longer functions. The kinks of unsaturated fatty acids prevent freezing and lower the freezing/melting point of the membrane-keeping it fluid at lower temperatures. Pond goldfish have the ability to change the composition of their membranes to adapt to the winter season each year. As the temperature drops, they replace some of the saturated FA with unsaturated FA in the cell membranes of certain organs such as the brain-allowing the processes of the organs to continue despite the drop-in temperature. HUFA act as anti-freeze for cold-blooded animals. Keep in mind that these FA also serve as precursors to many biologically important molecules which are involved in a variety of other important processes in the animal body.
It is now clear that unsaturated FA play an important role in fish health. HUFA are a subset of unsaturated FA which contain 20 or more carbon atoms and multiple double bonds. Common HUFA encountered in fish nutrition are EPA and DHA-both ω3 FA. EPA and DHA are essential for fish health. These HUFA must either be obtained in the fish’s diet, or made through the conversion of other FA such as Linolenic Acid-although not all fish are capable of this or efficient at the process, making incorporation in the diet important. Studies suggest that fish benefit most from directly consuming the EPA and DHA as evidenced by increased rates of growth and survival.
The increased adaptability of a fish due to the anti-freeze qualities of HUFA helps to explain the observed increase in survival rates of fish. However, this doesn’t explain the increase in growth rates which have been noted. Here, it helps to understand that fats are very efficient means of energy storage-thanks to their hydrocarbon chains. The gasoline that runs our cars contains hydrocarbons which, through combustion reactions, release explosive energy. The cells of an animal body do the very same thing with fats. One gram of fat contains two times more energy than a gram of carbohydrate-meaning fish can be fed a smaller amount of a higher-fat content food and still consume as much energy as if they were fed a larger portion of a lower-fat food. Aside from the benefit of stretching your dollar, feeding less also reduces pollution of tank water which is a valuable benefit all its own.
Highest Quality Foods Contain HUFA – Clearly, the best foods to feed to your fish will be those which are rich in HUFA-due either to their ability to produce it themselves or through the consumption of other HUFA-rich organisms like gut fed insects. EPA and DHA are all derived from plants either directly or through the indirect conversion of linolenic acid from plants to EPA and DHA. Phytoplankton are similar to plants. They are autotrophic and many are able to make HUFA. The zooplankton which consume them benefit the most by consuming those which are rich in HUFA. This transfer of HUFA up the food chain to organisms such as mysis and brine shrimp leads to the incorporation of the HUFA in fish’s cells. The greater the proportion of HUFA in the food fed to fish, the greater amount of energy for growth and survival is obtained from it. Fats are very high in energy and there is evidence to suggest that foods with higher levels of HUFA are more nutritious as they are a more efficient means of transferring energy up the food chain. Foods which are more efficient at providing energy are higher-quality foods and a better value for your money. This is why dried foods such as mysis, plankton, cyclops, and others are an important staple of a well-rounded aquatic diet. Evidence suggests that frequent feedings of at least two or more different dried foods each week will greatly enhance the growth and reproduction of most fish.
Onto 2018 and what is planned for the future of aquaculture feeds
There are two distinct pathways leading to the biosynthesis of LC-PUFA in nature: 1. The conventional (aerobic) fatty acid desaturation/elongation pathway, and 2. The anaerobic polyketide synthase (PKS) pathway. The PKS route is similar to those involving the PKS complexes in antibiotic synthesis. No reports of successful expression of the PKS pathway in land plants have emerged to date. In contrast, insertion of the aerobic pathway leading to DHA production, into omega-3 C18 PUFA accumulating land plants, has been reported in a number of studies. Transfer of genes from microorganisms to land plants led to accumulation of 2.4% EPA and 0.5% DHA in Arabidopsis (Mouseear cress, later improved to 4% EPA and 1% DHA)–(the first reporting of a (model) land plant with DHA), 15% EPA and 0.2% DHA in Brassica juncea (Indian mustard) , 19.6% EPA and 3.3% DHA in soybean..
These initial findings from a number of research teams clearly indicate the feasibility of developing grain crops with significant amounts of LC omega-3 oil. Further research is required to develop commercial oilseed crops with LC omega-3 oil and increased levels of DHA in particular are still required. It is interesting to point out, that as little as one tablespoon (~10 mL) of soybean oil containing 20% of EPA could make a significant contribution to the recommended dietary intake of the beneficial omega-3 LC-PUFA. Considerable effort is now being focused on increasing the levels of DHA and it is not unrealistic to hope that DHA levels of 20% can be achieved in transgenic plants in the next few years.
Future novel land-based plants will likely provide the most economically viable source LC omega-3 oil for aquaculture and other applications. A land plant source of LC omega-3, if achieved and assuming their cultivation will be permitted, will be cheaper than using yeast or microalgae and could be used in fish feeds to help deliver increased health benefits to farmed bettas and aquaculture fish. Research involving the use of microbial genes in land plants has so far led to increases the production of LC omega-3 in a number of land plant species. This future may be as little as five years away, although perhaps longer in the context of aquaculture feeds and for products for direct human consumption in particular to meet all the permitting requirements that are likely to be in place in 15 years.
Aquaculture feeds of cricket flour in place of fish meal has shown 30% increases of fatty acids in farmed fish over a 4-month time period. The mean that from egg to breeder is down to less than 4 months and egg to sales are down to 3 months on bettas. That is over 25% shorter time to market than all previous foods combined.
Crickets are also important sources of numerous necessary nutrients such as the 8 essential amino acids, vitamin B12, riboflavin, the biologically active form of vitamin A (retinol, retinoic acid, and retinaldehyde) and several minerals such as Iron and Calcium. Crickets are also high in healthy and low in unhealthy fats and oils: low in saturated fat, rich in omega 3 fatty acids, and with the ideal ratio of Omega 6 and 3 fatty acids
The fatty acid content and composition of the house cricket Acheta domesticus have been investigated in entire insects at different developmental stages and in selected organs of male and female adults. We have also determined the fatty acid composition of the various lipid classes within extracts of the organs of adult female insects. Fatty acids were analysed by capillary gas chromatography or mass spectrometry as their methyl esters (FAMEs) after direct transesterification of insect material or separated lipid classes.The major esterified fatty acids in all extracts were palmitate (C16:0), stearate (C18:0), oleate (C18:1) and linoleate (C18:2). Levels of esterified fatty acid varied considerably between organs but the fatty acid compositions showed only small variations. The levels of polyunsaturated fatty acids of the C18 series were considerably higher in phospholipid fractions than in other lipid classes. Triacylglycerols formed the major lipid class in ovaries, fat-body and newly-laid eggs, whereas diacylglycerols and phospholipid predominate in the haemolymph. Triacylglycerols, phospholipids, diacylglycerols and free fatty acids were all found in significant amounts in the gut tissue. While omega-9 was found to be the main source of fatty acids. The mealworm had more lipids at over 32% while crickets had around 15%. But EFA’s when compared to all other sources of feed was over 20% more. If HUFA can be lab grown from a cheap source like bio fuel leftovers then there is a real market for this food powder for the commercial betta farm.
The chemical composition and the nutritional quality of protein, fatty acids and chitin of adult field cricket Gryllus testaceus Walker were investigated. The adult insect contained: crude protein 58.3 %; fat 10.3 %, chitin 8.7 % and ash 2.96 % on dry matter basis respectively. The essential amino acid profile compared well with FAO/WHO recommended pattern except for cysteine and methionine. The fatty acid analysis showed unsaturated acid of the field cricket to be present in high quantities, and the total percentage of oleic acid, linolic acid and linolenic acid was 77.51%. The chitin content of the insect was 8.7% with a better quality than the commercial chitin that was prepared from shells of shrimp and crab. Therefore the chemical composition of the field cricket indicates the insect to be a good supplement to nutrition for food and feed, even a raw material for medicine. So are we on to something here, we think so. 2019 we will introduce our betta feed diets to farms around the world as a green substantiated feed source that is far superior to grain and fish meal foods.
Thanks to our research partners below and all who have put in the time to prove a sustainable green aquaculture feed is replacing fish meal in 2019.
Statistical analyses were performed using Minitab® v.17.1.0 statistical software (Minitab Inc., PA, USA).
nutraingredients-asia for the raw source powders.
Bays H. Clinical overview of Omacor: a concentrated formulation of omega-3 polyunsaturated fatty acids. Am. J. Cardiol. 2006;98:71–76. [PubMed]
Nichols P.D., Virtue P., Mooney B.D., Elliott N.G., Yearsley G.K. Seafood the Good Food. The oil content and composition of Australian commercial fishes, shellfishes and crustaceans. FRDC Project
Tacon A.G.J. Review of the state of world aquaculture, FAO Fisheries Circular. FAO; Rome, Italy: 2003. Aquaculture production trends analysis; pp. 5–29.
Naylor R.L., Hardy R.W., Bureau D.P., Chiu A., Elliott M., Farrell A.P., Forster I., Gatlin D.M., Goldburg R.J., Hua K, Nichols P.D. Feeding Aquaculture in an Era of Finite Resources. Proc. Natl. Acad. Sci. 2009;106:15103–15110. [PMC free article] [PubMed]
Glencross B. Exploring the nutritional demand for essential fatty acids by aquaculture species. Rev. Aquaculture. 2009;1:71–124.
Scire T. AIT Exploring the nutritional demand in bettas for essential fatty acids vs growth from metabolic engineering of long chain polyunsaturated fatty acids. 2018;1:28- 32
Sukura labs Japan