Environmental Resources
Unit C
Animal Wildlife Management
Problem Area 3
Fish Management
Describing nutritional
requirements of fish
Lesson 3
Describing nutritional requirements
of fish
• From the nutritional labels provided:
– Write amount of fat, carbohydrates, proteins,
and vitamins.
• What types of foods provide us with the
different nutrients?
• How does fish receive these nutrients?
Terms
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Amino acid
Blood meal
Carbohydrates
Carnivore
Fat-soluble vitamins
Fats
Fish meal
Herbivore
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Minerals
Omnivore
Protein
Soybean meal
Trace elements
Vitamins
Water-soluble
vitamins
Objectives
• Describe the role of protein in fish
nutrition.
• Describe the role of fats in fish nutrition.
• Describe the role of carbohydrates in fish
nutrition.
• Describe the role of minerals in fish
nutrition.
• Describe the role of vitamins in fish
nutrition.
What is the role of protein in fish
nutrition?
• First major component
required for proper
nutrition of fish is
protein.
• Protein
– Formed from
compounds known
as amino acids.
ag.arizona.edu/aes/mac/catfish.htm
What is the role of protein in fish
nutrition?
• Amino acids
– Building blocks of protein.
– Needed by animals for proper nutrition.
– 10 amino acids are essential.
– Broken down during digestion.
– Used to produce new tissue or
reproduce damaged tissue.
Protein
• Most critical component of fish feed.
• Prepared fish feed will contain between 25 and
40 percent protein.
agrino.org/fishing/htmldocs/
frswtrfish.html
Sources of protein
– Fish meal
• High protein feed derived from fish.
– Animal waste products
• Blood meal
–High protein feed derived from blood
collected during the slaughter process.
• Meat scraps
– Soybean meal
• High protein feed produced from soybeans.
Protein requirements
• Carnivore fish
– Animals that eat meat.
– Require 50% of its protein from animal
sources.
• Herbivore fish
– Animals that eat plants.
– Need only about 30% of the protein in their
feed from animal sources.
• Omnivores
– Animals that eat both plants and animals.
– Need only about 30% of the protein in their
feed from animal sources.
What is the role of fats in fish
nutrition?
• Fats
– A required component of fish feeds.
– Composed of fatty acids.
– Used for proper health and growth.
– Amount of fat in a feed usually between 4 and
15 percent.
Fat requirements
• Type of fat needed in fish feed depends on
temperature of water.
• To be digested, fat must be able to melt.
• To melt, must have melting point below water
temperature.
• Cold water fish (trout)
– Unsaturated fat derived from plants
(vegetable oil).
• Warm water fish (tilapia)
– Saturated fat derived from animal products.
What is the role of carbohydrates in
fish nutrition?
• Carbohydrates
– A required component of fish feed.
– Source of energy for fish.
– Organic compounds composed of carbon,
hydrogen, & oxygen.
– Plants including sugars, starches, and
cellulose are sources.
Carbohydrate requirements
• Fish herbivores (carp)
– Better capable of digesting carbohydrates.
– An enzyme (amylase) in their digestive
system.
• Fish carnivores (catfish)
– Can’t digest carbohydrates as well.
– Only need 10% carbohydrates in ration.
What is the role of minerals in fish
feed?
• Minerals
– Inorganic materials needed for health and
growth.
– Most only needed in small amounts.
– Large amounts of minerals may be fatal to
fish.
– Often called trace elements
• Needed in very small quantities.
Required Minerals
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Calcium
Iron
Silicon
Manganese
Magnesium
Boron
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Cobalt
Copper
Iodine
Molybdenum
Selenium
Sodium
www.teezz.co.uk/fishing/
catfish-2795/index.shtml
Minerals
• Testing the water can show mineral
deficiencies.
• Can give fish two ways
– Add directly to the water.
• If water is flowing or moving may be a
waste
– Added to a commercially prepared feed.
What is the role of vitamins in fish
nutrition?
• Vitamins
– Organic compounds needed in small amounts
for proper growth and maintenance of body
functions.
– Specific vitamins are needed for different
body functions.
– Deficiencies can cause poor growth, anemia,
skin lesions, clubbed gills and other problems.
Types of Vitamins
• Water-soluble
– Taken in, used, and then excreted.
– Include Thiamin, Riboflavin, and Folic Acid.
• Fat-soluble
– Taken in to the body and stored.
– If excess amounts consumed can be
unhealthy.
– Include vitamin E, A, and D.
Review / Summary
• What is the role of protein in fish nutrition?
• What is the role of fats in fish nutrition?
• What is the role of carbohydrates in fish
nutrition?
• What is the role of minerals in fish
nutrition?
• What is the role of vitamins in fish
nutrition?