Mineral Requirements of Fish

Minerals are a type of basic elements. Mineral elements are the inorganic elements that are required for the management and maintenance of important physiological processes in the organism. Some important minerals are Calcium, Phosphorus, Sodium, Sulfur etc. Minerals act as biological catalysts for enzymes, hormones and protein in the body.

About 23 types of inorganic minerals perform the necessary functions in the organism. Of these, 7 are the minerals that the body needs in sufficient amount and such minerals are referred to as macro-elements. On the other hand, 16 minerals are required in very small amounts in the body of the organism; such minerals are called micro-elements or Trace Minerals.

Secondary elements play a major role in the nutrition and production of fish along with other minerals. Supplemental food and water serve as a source of fish minerals. Fish can absorb these elements as ions with the help of gills and skin. Rui fish(Labeo rohita) get essential minerals from plankton and pond bottom animals and decomposed organic matter. In the absence of such elements, the growth of fish is reduced or diseases are caused by pests, their high presence also hinders the growth rate of fish. Fish not only absorb such inorganic nutrients through food but also from the external aquatic environment. Inorganic elements are inextricably linked with the way fish live.

General Functions of Minerals

Minerals play a role in regulating physiological functions and the maintenance the body of the organism. It plays the following role:

It plays a role in the formation of the external skeleton;
It plays a role in transfer of nerve stimulation and muscle contraction;
It plays a role in the formation of structural elements of cell tissues;
Acts as key ingredient in bone and tooth formation;
It plays an important role in absorption, controlling stress, diffusion, etc.;
Acts as essential component of enzymes, hormones and vitamins;
Maintains acid-base balance;
Regulates blood formation, blood clotting barriers and the normal functioning of the thyroid gland;
Assists in performing water metabolism, controlling blood volume and transporting gaseous material;
Electron transfer;
Enzyme activation;
Homeostasis control;

Classification of Minerals

Not all minerals are needed in the same amount in a fish diet. Minerals are mainly divided into the following two groups based on the amount of organisms needed.

1. Macro elements
2. Micro elements

1. Macro Elements: The minerals that are needed in large quantities for the normal growth of fish are called the main minerals or macro elements. Generally, 100 mg or more of these minerals are required in every kg of fish diet. There are 7 main minerals for fish such as Calcium, Magnesium, Sodium. Potassium, Phosphorus, Sulfur and Chlorine.

2. Micro Elements: For normal growth of fish, some minerals are required in very small amounts in the body of fish i.e. less than 100 mg per kg of balanced diet of fish and this small amount meets the nutritional needs of fish, such minerals are called secondary minerals or micro lements. There are 16 such minerals which are required in very small amounts in the body of the organism such as iron, iodine, copper, zinc, manganese, cobalt, molybdenum, silicon etc.

The following table lists the important major and minor mineral elements:

Macro Elements	Micro Elelents
Calcium (Ca) Magnesium (Mg) Sodium (Na) Potassium (K) Phosphorus (P) Chlorine (Cl) Sulfur (S)	Iron (Fe) Zinc(Zn) Manganese (Mn) Copper (Cu) Iodine (I) Cobalt(Co) Nickel (Ni) Fluorine (F) Chromium(Cr) Molybdenum (Mo) Selenium(Se) Vanadium (V) Tin(Sn) Silicone(Si) Aluminum (Al) Arsenic(As)

Macro Elements

Calcium(Ca)

Calcium is a chemical mineral and has atomic number of 20. Calcium is found in the skeletons and scales of bony fish. It plays a role in regulating various physiological processes such as metabolism, nerve and muscle contraction and osmosis. Calcium is absorbed directly through the gastrointestinal tract, gills, skin and fins, and oral epithelium with the effectiveness of vitamin D₃ and lactose. In freshwater fish, most of the calcium is absorbed through the gills and skin, and in marine fish it is absorbed through drinking water. Calcium intake varies due to differences in species and water chemistry. The required calcium intake of eel and carp is 0.34 percent.

Sources of Calcium

Limestone
Shell of snails and oysters
Crushed bones
Crab crushed
Rocky phosphate (30-40%)
Shrimp meal
Fish meal
Meat meal
Kelp meal
Alfalfa meal
Poultry droppings
Dry skim milk

Biological Function of Calcium

Calcium is directly involved in the development and formation of bones. It also plays an important role in a variety of physiological functions. Below are some important roles of calcium:

It is an important component of bones, cartilage of fish and also components of shells of crustaceans such as shrimp/prawn.
It stimulates the nucleus accumbens and releases thromboplastin to clot the blood.
It acts as a catalyst for a variety of enzymes such as pancreatic lipase, acid phosphatase, cholinesterase, ATPases, and succinic dehydrogenase.
It stimulates muscle contraction by activating enzymes, transferring aerobic consciousness from one cell to another.
It jointly with phospholipids regulates the permeability of cell membranes.
It plays an important role in the absorption of vitamin B₁₂ in the stomach and digestive tract.
Regulates muscle contraction and expansion.
It plays an important role in nerve stimulation and transfer.
It regulates various functions of cells.
It regulates acid-base balance.

Phosphorus

It is a nucleic acid and an important component of the cell membrane. Phosphorus is a nonmetallic chemical mineral with atomic number of 15. It directly participates in cellular reactions in all types of energy production. It contributes to the metabolism of sugars, lipids and amino acids. Phosphorus is also found in skeletons and scales of bony fish. It acts as a component of different types of metabolic reactions and different types of molecules such as ATPase. Dissolved phosphorus is absorbed directly through the skin, fins and gills. Water usually contains very little phosphorus. Therefore, supplementary food plays an important role in filling the phosphorus deficiency. Vegetable foods such as cereals and oilseeds contain 50-60% phosphorus which is present as calcium or magnesium salts of phytic acid.

Sources of Phosphorus

Limestone
Bone meal
Meat meal
Fish meal
Poultry droppings
Rice husk,
Wheat husk
Yeast
Sunflower Seed meal
Cotton seed meal
Rape seed meal

Biological functions of Phosphorus

The main biological functions of phosphorus are mentioned below:

It is an important component of bones, cartilage and and shells of crustaceans .
It acts as an important component of phospholipids, nucleic acids, phosphoproteins such as casein, high-energy phosphate esters such as anion, hexose phosphate, creatine phosphate, and numerous enzymes.
It regulates acid-base balance.
It plays an important role in the metabolism of sugars, lipids and amino acids.
Moreover, it participates in the metabolic system of various body fluids.

Deficiency Signs of Phosphorus

The growth of fish is reduced;
The growth of fish is reduced;
Bone loss or deformity;
Disability of the cranial nerve;
It helps in increasing the amount of fat in the digestive tract;

Magnecium

It is a chemical mineral with atomic number of 12. It regulates the activity of important biological polyphosphate compounds such as ATP, DNA, and RNA and acts as a cofactor in a variety of enzymatic reactions. It plays an important role in respiratory adaptation of freshwater fish. It is absorbed directly through the digestive tract, gills, skin and fins. It is found in phytin (Ca or Mg salt of phytic acid) in vegetable foods along with calcium and phosphorus.

Sources of Magnecium

Meat and bone meal
Rice husk
Kelp meal
Sunflower Seed meal
Wheat husk
Tishi seed meal
Shrimp meal
Cotton seed meal
Crab crushed
Grass chicken droppings

Biological functions of Magnecium

The main biological functions of magnesium are mentioned below:

It is an important component of bones, cartilage and crustaceans shells.
It contains various major enzyme systems such as kinases, mutases, muscle ATPases and enzymes such as cholinesterase, alkyne phosphatase.
It acts as a catalyst for inlase, isocytic dehydrogenase, arginine, deoxyribo nuclease and glutaminease.
It plays a role in regulating intracellular acid-base balance.
It plays an important role in the metabolism of sugars, carbs and fats.t

Deficiency Signs of Magnecium

The tendency of fish to eat decreases;
Physical growth decreases;
The vertebrae, muscle fibers, epithelial tissues of the pyloric system and gill filaments are eroded.
Blindness
Renal calcinosis

Sodium

It is a chemical mineral element with atomic number of 11. Sodium is the monovalent ion of extracellular fluid. It is found in the bloodstream and 93% of the total ions are sodium ions. It regulates osmotic pressure and pH levels. This material is absorbed directly through the alimentary canal, gills, skin and fins.

Sources of Sodium

Shrimp meal
Fish meal
Meat meal
Bone meal
Molasses
Alfalfa meal
Wheat husk
Rice husk
Cotton seed meal
Soybean meal
Sunflower Seed meal
Salt

Biological Functions of Sodium

Controlling osmotic pressure and acid-base balance.
It also plays a role in the absorption of sugars.

Deficiency signs of Sodium

Loss of appetite
Reluctance to take food
Drowsiness
Muscle contraction etc.

Potassium

Potassium is a chemical mineral and its atomic number is 19. It plays role in activating all the functions of the cells of the organism. It helps in nerve stimulation in the organism and without it, the heart cannot function properly. Potassium is the main positive ion of intracellular fluid and is absorbed directly through the digestive tract, gills, skin and fins. It also meets the needs of fish through supplementary food.

Sources of Potassium

Shrimp meal
Fish meal
Meat meal
Bone meal
Molasses
Wheat husk
Rice bran
Cotton seed meal
Soybean meal
Sunflower seed meal
Potassium chloride

Biological Functions of Potassium

It regulates intracellular osmotic pressure and acid-base balance.
It also plays an important role in the synthesis of glycogen and meat and also in the metabolism of glucose.

Chlorine

Chlorine is a chemical mineral with atomic number of 18. It is the main monovalent negative ion of extracellular fluid. It makes up 65% of the total negative ions in blood cells and other extracellular fluids. This material is absorbed directly through the digestive tract, gills, skin and fins when dissolved in water. In addition, the fish get it through supplemental food.

Sources of Chlorine

Shrimp meal
Fish meal
Meat meal
Bone meal
Molasses
Wheat bran
Rice bran
Cotton seed meal
Soybean meal
Sunflower Seed meal
Rape seed meal
Potassium chloride

Biological Functions of Chlorine

It maintains osmotic pressure and acid-base balance.
It transports oxygen and carbon dioxide.
It regulates the pH of digestive juices.

Deficiency Signs of Chlorine

Normal growth is abolished
Aversion to food
Bone loss

Sulfur

It is a chemical mineral and has atomic number of 16. It is found in essential amino acids such as methionine and non-essential amino acids such as cysteine, cysteine and taurine. It is also found in vitamins thiamine and biotin. It plays a role in the production of bile for digestion. It is absorbed directly through the digestive tract, gills, skin and fins.

Sources of Sulfur

Fish meal
Kelp meal
Eggs
Feather meal etc.

Biological Functions of Sulfur

Sulfur is an essential component of various amino acids (such as methionine and cysteine), vitamins (thiamine and biotin), insulin and shells of crustaceans.
It forms heparin, chondroitin, fibrinogen, and taurine.
It plays a role in eliminating the toxicity of various aromatic compounds in animals.
It accelerates the activity of major enzyme systems such as co-enzyme A and glutathione.

Deficiency Signs of Sulpher

Skin problems
Inflammation of the muscles
Blood circulation is interrupted

Micro Element

Iron(Fe)

Iron is a chemical mineral with atomic number of 26. Iron is an essential element of cellular respiration. It participates in cellular respiration through oxidation and deoxidation and electron transfer. It is present in the body as complex compounds with proteins such as hemoglobin (hemoglobin and myoglobin), heme enzymes (eg. cytochrome, catalase). Iron adequacy and absorption are affected by phosphorus, calcium, phytate, copper and zinc. It is absorbed directly through the digestive tract, gills, skin and fins. The amount of iron required for catfish is 30 mg / kg of food.

Sources of Iron

Bone meal
Sunflower Seed meal
Alfalfa meal
Crab crushed
Fish meal
Poultry droppings
Yeast
Molasses
Rice bran

Biologicl Functions of Iron

It is an important component of pigments such as hemoglobin and myoglobin.
It is an important components of various enzyme systems such as cytochrome, catalase, peroxidase and various enzymes such as xanthin, aldehyde oxidase and succinic dehydrogenase.
It plays a role in transporting oxygen and electrons in the body.
It plays an important role in oxidative phosphorylation.

Deficiency Signs of Iron

Anemia
Decreased physical growth
Reluctance to take food.

Zinc(Zn)

It is a chemical mineral and has atomic number of 30. Fish usually absorb zinc from water and supplements. It is absorbed directly through the digestive tract, gills, skin and fins. The presence of zinc in the diet is influenced by phytate, phosphorus, calcium and copper.

Sources of zinc

Fish meal
Chicken excrement
Wheat bran
Wheat husk
Rice husk
Crab crushed
Sunflower seed meak
Yeast
Cattle excrement etc.

Biological Function of zinc

It contains more than 80 metallic enzymes such as carbonic anhydrase, gutamic dehydrogenase, alkaline phosphatase, pyridine nucleotide dehydrogenase, alcohol dehydrogenase, superoxide dismutase, pancreatic carboxipeptidase, tryptophan and dismolase. Carbonic anhydrase plays a role in the excretion of carbon dioxide and hydrochloric acid in the stomach through the blood.
It acts as a cofactor of various enzyme systems such as arginine, inolose, numerous peptides and tryptophan dissociation.
It plays a role in the metabolism of lipids, carbohydrates and sugars and also plays an important role in the synthesis of carcinogens and nucleic acids.
It supports the activity of various hormones such as insulin, glucagon, corticotrophin, FSH and LH.
It plays an important role in wound healing.

Deficiency signs of Zinc

Aversion to food
Decreasing the growth rate
Skin and fins erosion
Dwarfism
Higher mortality
Decreased immunity
Bone loss
Decreased egg production etc.

Manganese(Mn)

Manganese is a chemical mineral. Its atomic number is 25. It is not found in nature as a free ingredient but is found simultaneously with calcium. It is absorbed in the digestive tract, gills, fins and skin through the dissolved state of water. Its adequacy and absorption are affected by phytate and calcium.

Sources of Manganese

Kelp meal
Rice husk
Dry excrement of ducks
Palm fronds
Crab crushed
Wheat husk
Dry excrement of cattle
Molasses
Mustard oil cake meal
Rape seed meal
Sesame seed meal
Sun flower seed meal
Shrimp meal etc.

Biological Function of Manganese

It is an essential component of the enzyme pyruvate carboxylase.
It acts as a cofactor of numerous enzyme systems.
Red blood cells play a role in production, sugar metabolism and reproduction.
It synthesizes mucopolysaccharides in fish and forms bones.
It transfers the phosphate group by activating various enzymes (phosphate transferages and phosphate dehydrogenases) in the body.
It also plays a role in activating various enzymes involved in the citric acid cycle such as arginine, alkaline phosphatase and hexokinase.

Deficiency Signs of Manganese

Decreased physical growth
Loss of appetite
Imbalance
Dwarfism
Abnormal growth of tail fin
Mortality increases
Blindness etc.

Copper (Cu)

Copper is a chemical mineral with atomic number of 29. It is a flexible metal rich in high heat and electrical conductivity. It is absorbed into the digestive tract, gills, fins and skin through water. Its adequacy and absorption are affected by phytate, zinc, iron, molybdenum, cadmium, inorganic sulfate and calcium carbonate.

Sources of Copper

Molasses
Soybean meal
Crab crushed
Cotton seed meal
Poultry droppings
Fish meal
Maize meal

Biological Functions of Copper

It is an important component of the oxidation-deoxidation enzyme system such as cytochrome oxidase, uricase, tyrosinase, superoxide dismutase, amine oxidase, lysil oxidase and ferro-oxidase.
It plays a role in iron metabolism, hemoglobin synthesis, red blood cell production and maintenance.
It plays a role in the production of melanin pigment, the production of bone and connective tissue and the preservation of the myorin lining of the nerves.

Deficiency Signs of Copper

Decreased physical growth,
Blindness
Hitra disease

Cobalt (Co)

Cobalt is a chemical mineral with atomic number of 27. It is the active ingredient of cobalamin or vitamin B₁₂ which is essential for all kinds of animals. The adequacy and absorption of cobalt is affected by iodine levels. It is absorbed in the digestive tract, gills, fins and skin through the dissolved state of water.

Sources of Cobalt

Fish meal
Rape seed meal
Meat meal
Cotton seed meal
Soybean meal
Coconut curnels etc.

Biological Functions of Cobalt

It is an integral part of cyanocobalamin (vitamin B₁₂).
It plays an important role in the production of red blood cells and the maintenance of nerve endings.
It acts as an active agent in various enzyme systems.

Deficiency Signs of Cobalt

Anemia
Physical growth decreases
Reproduction is interrupted
Nervous weakness

Iodine (I)

Iodine is a chemical mineral with atomic number of 53. It regulates the normal metabolism of cells. Fish absorb dissolved water through the digestive tract, gills, fins and skin. Fish also get the necessary iodine through supplemental food. Adequacy and absorption of iodine is affected by cobalt levels

Sources of Iodine

Sea weed meal
Marine fish meal
Marine crustacean meal

Biological Functions of Iodine

It is an integral part of the thyroid hormone thyroxine and tri-iodothyronine.
It regulates the metabolic rate of all the bodily processes in the body.

Deficieny Signs of Iodine

Thiroid hyperplasia

Selenium(Se)

It is a chemical mineral with atomic number of 34. It is needed in very small amounts in the body of the animal which keeps the cell tissue activity active but if taken in large quantities, poisoning occurs in the animal body. Dissolved selenium is absorbed by water through the digestive tract, gills, fins and skin. Fish also get the required selenium through supplemental food.

Sources of Selenium

Fish meal
Rape seed meal
Meat meal
Alfalfa meal
Dry poultry droppings
Maize meal
Wheat bran
Feather meal
Yeast

Biological Functions of Selenium

It is an integral part of the enzyme gutathione peroxidase.
It protects cells and cell membranes from the harmful effects of peroxide.
It participates in the synthesis of ubiquinone (co-enzyme Q) and plays a role in cellular electron transport.
Vitamin E plays a role in absorption and maintenance.
It produces vitamin C.
It helps in the functioning of the thyroid gland.

Deficiency Signs of Selenium

The growth of fish is slow
Mortality increases
Anemia
Blindness or cataracts in the eyes
Muscle tissue decay

Chromium (Cr)

Chromium is a chemical mineral and its atomic number is 24. It contributes to the metabolism of glucose, carbohydrates and lipids. Animals need a very small amount (trace amount) but if they take more than they need, poisoning occurs in the body. Fish absorb selenium dissolved in water through the digestive tract, gills, fins and skin. Fish also get the required selenium through supplemental food.

Sources of Chromium

Shellfish meal
Liver
Dried poultry droppings
Artemia
Shrimp meal
Yeast

Biological Functions of Chromium

It is an integral part of glucose tolerance factor or GTF.
It acts as a cofactor of the hormone insulin.
It plays a role in the metabolism of sugar, cholesterol and amino acids.
It synthesizes glycogen.

Deficiency Signs of Chromium

The growth of fish is canceled
Anorexia or loss of appetite

Table: Sources of minerals, metabolic functions, deficiency symptoms and required levels at a glance

Name of Minerals	Sources	Metabolic functions	Deficiency symptoms	Required dose / kg in dry food
Calcium	Limestone, oyster shells, bone meal, shrimp shells	Forming fish bones and shrimp shells, helping blood to coagulate, activating catalysts.	Decreased physical growth, reluctance to eat, bone decay	5 gm
Phosphorous	Fish meal, Rice bran, Bone meal, Dried poultry droppings	Fish bone and shell formation, energy conversion, accelerating metabolism, controlling the body's acid-base balance.	Decreased physical growth, reluctance to eat, bone decay	7 gm
Magnecium	Rice bran, meat meal, crab crushed, Dried chicken droppings, seasame seed meal, sunflower seed meal	Fish and shrimp shell formation, catalytic activation, regulation of body acid-base balance and acceleration of metabolism.	Decreased physical growth, reluctance to eat, bone loss	500 mg
Sulfur	Fish meal, Eggs	An important component of amino acids, resistant to toxins in the body of fish, plays a role as a component of organic matter.	Skin problems, muscle inflammation, blood circulation is disrupted	3-5 gm
Iron	Blood meal, Bone meal, Dried poultry droppings, Crab crushed, Coconut cornels, sunflower seed meal, Alfalfa meal, kelp meal	The main components of blood such as hemoglobin, myoglobin production, oxygen supply to different parts of the body, essential elements of catalysts, lipid oxidation, cytochrome and other enzyme production.	Anemia, decreased physical growth, reluctance to eat.	50-70 mg
Zinc	Fish meal, Poultry droppings, Wheat husk, Sunflower seed mael	Metabolism of lipids, proteins and sugars, important components of metallic catalysts, co-regulators of catalysts, synthesis of nucleic acid metabolism, inhibition of virus attack, increase in antibody production, co-role of hormones.	Loss of appetite, fins and skin decay, dwarfism, increased mortality, bone loss, decreased egg production, decreased physical growth, etc.	10-100 mg
Cobalt	Fish meal, Meat meal, Coconut cornels, cotton seed meals, Rape seed meal, Soybean meal	Vitamin B12 synthesis, formation of red blood cells, maintenance of nerve cells, activation of catalysts of various enzyme systems.	Anemia, Decreased physical growth, Impaired reproduction, Neurological weakness	4-10 mg
Sodium	Kelp meal, shrimp meal, fish meal, meat meal, bone meal, Molasses, Alfalfa meal. Yeast, Wheat husk, Rice bran, Cotton seed meal, Sunflower seed meal, peanut or nut meal, Rape seed meal, salt and potassium chloride.	Acid-base equilibrium control, osmosis control	Loss of appetite, reluctance to eat, drowsiness, muscle contractions etc.	1-3 mg
Chlorine	Kelp meal, shrimp meal, fish meal, meat meal, bone meal, Molasses, Alfalfa meal. Yeast, Wheat husk, Rice bran, Cotton seed meal, Sunflower seed meal, peanut or nut meal, Rape seed meal, salt and potassium chloride.	Controlling digestive juices production, controlling acid-base balance	Normal growth is lost, aversion to food, bone loss	1-5 gm
Potassium	Kelp meal, shrimp meal, fish meal, meat meal, bone meal, Molasses, Alfalfa meal. Yeast, Wheat husk, Rice bran, Cotton seed meal, Sunflower seed meal, peanut or nut meal, Rape seed meal, salt and potassium chloride.	Playing a role in the functioning of the nervous system, controlling osmosis	Decreased physical growth, aversion to food, imbalance etc.	1-3 gm
Copper	Whaet bran, Rice bran, Cotton seed meal, Soybean meal, Fish meal	Ingredients of hemocyanin (cephalopod), tyrosinease and ascorbic acid as cofactors of oxidase	Decreased physical growth, blindness, Hitra disease - It is a type of bacterial disease.	1-4 gm
Manganese	Rice bran, Kelp meal, Crab crushed, Wheat husk, Dried poultry droppings	Cofactors of arginase and other metabolic enzymes, bone formation and red blood cell formation, epithelial tissueformation and maintenance, sugar metabolism, amino acid metabolism etc.	Decreased physical growth, loss of appetite or loss of appetite, imbalance, dwarfism, abnormal growth of tail fin, increased mortality, blindness, etc.	20-50 mg
Iodine	Marine fish meal, Sea weed meal	Ingredients of thyroxine hormone, reproduction, growth and replenishment, help in blood supply to the body, control of all metabolic functions in the body, control of oxygen consumption	Thiroid hyperplasia	100-300 mg
Molybdenum	Fish meal, cotton seed meal, Yeast, Bone meal	Acts as a cofactor of xanthine, oxidase hydrogenase and reductase	Decreased physical growth, reluctance to eat	Trace amount
Chromium	Bone meal, Shrimp/snail shell crushed, Liver	Collagen formation, increasing the effectiveness of insulin, regulating the rate of glucose metabolism	Fish growth is curtailed, reluctance to eat or loss of appetite	0.7 mg
Selenium	Fish meal, cotton seed meal, Yeast	Protects cells from the effects of peroxide, acts as an antioxidant in conjunction with vitamin E, helping to keep the body stress free.	Slows down the growth of fish, increases mortality, anemia, blindness or cataracts, loss of muscle tissue	0.19 mg

Table: Symptoms of fish poisoning due to excess mineral content

Minerels	Fish Species	Symptoms of Poisoning
Zinc	Cyprinus carpio	Decreased physical growth
Copper	lctalurus punctatus	Decreased physical growth
Serenium	Oncorhynchus mykiss	Decreased physical growth, higher mortality rate, increased calcium levels in the kidneys
Cadmium	Oncorhynchus mykiss /Cyprinus carpio	Scoliosis, low calcium levels in the bones,
Lead(Pb)	Oncorhynchus mykiss	Scoliosis, lordosis, anemia, caudal fin loss
Chromium	Oncorhynchus mykiss	Decreased physical growth