Fish Nutrition and Feed Formulation

Comprehensive vocabulary flashcards covering fish nutritional types, essential amino acids, vitamin/mineral functions, and commercial feed formulation methods based on Dr. Mukti Chanda's lecture.

Carnivores

Fish that consume primarily animal material, which may range from microscopic crustaceans and insects to amphibians or small mammals.

Herbivores

Fish that subsist primarily on vegetation and decayed organic material in the environment.

Omnivores

Fish that consume almost any food source, originating from either plant or animal sources.

Predators

A category of fish, such as Trout, which feed on animals large enough to be seen with the naked eye and possess well-developed teeth for grasping and holding prey.

Grazers

Fish like the Mullet that continuously feed on the bottom of the water habitat for plants or small animal organisms, taking food in well-defined bites.

Strainers

Fish such as the Menhaden that select food by size rather than type by straining water through gill rakers; an adult can strain over $6\text{ gal}$ per minute.

Suckers

Fish like the Buffalo fish that feed primarily on the bottom, sucking in mud to filter and extract digestible material.

Parasites

Fish such as the Lamprey that attach themselves to other animals and exist on the host’s body fluids.

Proteins

Long chains of amino acids linked by peptide bonds; they contain nitrogen and are the most expensive and important factor in fish growth performance.

Indispensable (Essential) Amino Acids

Amino acids fish cannot synthesize: Arginine, Valine, Histidine, Isoleucine, Leucine, Lysine, Methionine, Threonine, Tryptophan, and Phenylalanine.

Glycogen

The form in which carbohydrates are stored in fish to be mobilized for energy demands.

Carbohydrate Energy Extraction

Fish extract approximately $1.6\text{ kcal}$ from $1\text{ g}$ of carbohydrate, compared to mammal extraction of $4\text{ kcal/g}$.

Lipid Energy Content

Each gram of fat contains $2.5 \times$ the energy found in a gram of carbohydrates or proteins.

Hypervitaminosis

A toxic condition caused by excessive levels of fat-soluble vitamins (A, D, E, and K) stored in body tissues.

Choline

A water-soluble vitamin that serves as a membrane component, a precursor to acetylcholine, and a provider of methyl groups.

Vitamin C

A vitamin involved in connective tissue formation, bone matrix, wound repair, and iron absorption; it also prevents the peroxidation of fats.

Macrominerals

Minerals present in fish bodies in relatively large quantities, including Calcium ($Ca$), Chlorine ($Cl$), Magnesium ($Mg$), Phosphorous ($P$), Potassium ($K$), and Sodium ($Na$).

Microminerals

Minerals required in very small amounts, such as Copper ($Cu$), Iodine ($I$), Iron ($Fe$), Manganese ($Mn$), Selenium ($Se$), and Zinc ($Zn$).

Goitre

A condition in fish caused by an iodine deficiency that results in the growth of the thyroid gland.

Fibre

Indigestible plant materials like cellulose, lignin, and hemicellulose that add bulk to feed but increase faecal production.

Antioxidants

Synthetic substances like ethoxyquin, BHT, BHA, and propyl gallate used to prevent the oxidation of fats and vitamins in fish feed.

Carotenoids

Pigments like astaxanthin and canthaxanthin that provide the red to orange colour in salmonids; fish cannot synthesize these.

Pellet Binders

Substances such as sodium bentonites, lignosulfates, and guar gum that improve feed stability in water and reduce fines during handling.

Extruded Feeds

Floating or buoyant feeds manufactured via high-temperature processes that expand the pellet through starch gelatinization and increased porosity.

Pressure-pelleted Feeds

Sinking feeds made by compressing particles into dense solids using moisture, heat, and pressure.

Pearson Square Method

A simplified calculation technique used to determine the ratios for mixing different protein ingredients to reach a desired dietary protein level.

Best Buy Technique

A method of comparing feedstuffs based on the cost per unit of nutrient (e.g., $cost/kcal$) to formulate cost-efficient diets.

Demand Feeders

Feeders suspended above tanks that release a small amount of feed when fish strike a trigger rod extending into the water.