University:
York University
Course:
BIOL 4340 | Fish Biology
Academic year:

2019
Views:

32

Pages:

2
Author:

Nick T.

Module 5: Nutrition Digestion: Converting protein, carbs, and lipids into molecules Alimentary canal passing molecules Essential and non-essential Protein (AA for fish) Carbs Lipids Vitamins Minerals Intensive System benefits from natural production of supplements. Feed Organisms: Locating Food Visual detection Electrical impulses Sound (turbulent) Chemical Stimuli Zoo phytoplankton Benthos Filamentous algae Detritus Macrophytes Molluscs Fats/lipids: Best gram for gram. Then carbs, then protein. Poikilotherms do not regulate their body temp. As a result, they can convert feed to energy more efficiently than farm animals. Metabolic Rate influenced by: Temperature Activity Age or Size Seasonal Carbs = relatively cheap energy source. Excess carbs get stored as fats. Also give the feed some color, texture, help it float, binder. Protein: Most expensive part. Most utilized in Fry/spat because growth is so tremendous so quickly. (40-40% diet) Fish usually store protein as muscle. Influences: Temp, body size, stocking intensity, oxygen levels, toxins present, temp ↑ metabolic rate. Crustaceans need about 30-50% protein. Lipids: Natural diets can contain 50% fats. Lipids (cont.) High-melting points = not utilized well Imagine fuel that needs Blue Fire to ignite. Crustaceans need about 5-30% lipids. BUT typical feeds only contain about 10%. Carbohydrates: Abundant and Cheap Excess carbs stored as fats Also help as binder, floating, texture Vitamins: Minute part of diet. Catalytic for metabolic + physiological functions. Water Soluble: A bunch. Fat Soluble: ADEK Minerals: Calcium, Magnesium, phosphorus, Iron, Copper, Zinc, Iodine, Manganese, Selenium, Cobalt. More common in fishmeal. Deficiency: Poor growth, high mortality. Skeletal abnormalities. Inorganic fertilizer: NPK Soybean meal is most common ingredient in fish meal. Protein is the most expensive. Getting rid of uneaten food is important. Feed conversion ratio = Feed intake/weight gain. Heat treatment to increase nutritional value.