Aquatic animals rely on the physiological functions of sight, touch, taste and smell to actively search for food.  If a handful of feed is scattered in the fish pond, it will immediately attract the surrounding small fish to forage, which is obviously a feeding behavior induced by the physiological function of vision, because the chemical receptors of taste can induce fish to feed only after the dissolution of taste and the flow of water.  Does betaine as a nutritional additive in aquatic feed really lure fish?  

Betaine is a glycine trimethyl endolipid extracted from beet processing byproducts.  Studies have shown that betaine is one of the stimuli of taste in animals. A mere 0.0001 mol/L of betaine can induce a taste response in fish.  Cars believed that glycine type, β -alanine type and methyl ester of betaine had the strongest food-inducing effect on fish and shrimp, and betaine could improve the palatability of feed, increase food intake and shorten feeding time of animals.  Adding 0.3 % - 1.0% betaine in the diet of carp can induce food and promote growth.  

When betaine was added to the feed with 1.2-2.5% as attractive agent, it was found that the taste organs of all cultured fish were strongly stimulated, which could attract fish to swallow and avoid the waste caused by the feed sinking to the bottom of the pond.  Betaine has a good allure to the sense of smell and taste of Macrobrachium rosenbergii. Generally, the feeding time of Macrobrachium Rosenbergii is 1-1.5 h, and the feeding time of macrobrachium Rosenbergii is basically completed with 45MNi after betaine.  In addition, the luring effect of stelline also showed synergistic effect with some amino acids, which not only made fish taste sensation, but also enhanced the taste sensation of amino acids, so as to enhance the luring effect of amino acids.  Atlantic salmon and rainbow trout were reared with betaine and amino acid attractants in Finland sugar factory, which had good attractant and could shorten the feeding time greatly.