Environmental Resources

Unit C

Animal Wildlife Management

Problem Area 3

Fish Management

Identifying Fish Digestion and Feeding

Lesson 4

Identifying Fish Digestion and Feeding

• Make a list of what you have eaten in the last 24 hours.

• Where did you eat those foods at?

• How was the food served?

• How is the body able to digest and utilize the food you consumed?

Terms

• Anus• Auger feeding system• Automated feeding

systems• Blowers• Branchiospines• Carnivores

• Demand feeders• Esophagus• Hand feeding• Intestines• Mouth• Prepared feed• Stomach

Objectives

• Describe the fish digestive system.

• Describe the common methods of feeding fish.

• Understand how to interpret a feed label.

What are the parts of the fish digestive system?

• The digestive system is similar to other animals.

• Size and shape of each component of the system will vary with the type of fish and its diet.

• Carnivores– Fish that eats meat.– Have a large stomach and short intestines.

What are the parts of the fish digestive system?

• Parts include:– Mouth

• Teeth• Tongue• Branchiospines

– Esophagus– Stomach– Intestines– Anus

What are the parts of the fish digestive system?

• Mouth– Entry point of system.

• Carnivores mouth– Have many teeth that point inwards.– Not used for chewing.– Used to capture and hold prey.

• Other fish– Few or no teeth. www.vrmlsite.com/dec96/spot5.html

What are the parts of the fish digestive system?

• Tongue– Helps move food around in the mouth.

• Branchiospines– Act as filters to capture small food from water

as the fish swims.– Part of the gill structure that helps fish swim.

• Esophagus– Short tube that connects mouth to stomach.

What are the parts of the fish digestive system?

• Stomach– Organ where digestion begins.– Some stomachs will expand greatly.

• Allows them to eat large quantities of food.– Other stomachs are small that will

accommodate small amounts of food.– Some fish have almost no stomach.

• Esophagus connects directly to intestines.

What are the parts of the fish digestive system?

• Intestines– Site of food digestion

and nutrient absorption.

• Anus– Exterior opening of

system.– Unused food and

wasted material is exited.

www.mariner.org/library.html

What are some common methods of feeding fish?

• Feeding fish is very important.– Provide the appropriate nutrition.– Opportunity to observe fish for any abnormal

signs.

• Feeding systems differ based on size of the operation.– Small operations– Large operations

What are some common methods of feeding fish?

• Small Operations– Hand feeding

• Feed is distributed by hand, shovels, or other non-automated means.

• Most common method.• Used for feeds not suited for automated

systems.• Meat scraps are hand fed.

What are some common methods of feeding fish?

• Large Operations– Automated feeding systems

• Utilize machinery to distribute the feed.• From relatively simple to very complicated,

computer-controlled.• Blowers• Demand feeders• Auger feeding systems

What are some common methods of feeding fish?

• Blowers– Drive along the

side of the pond and blow feed out into the pond.

– Attached to trucks or tractors.

– Common in levee pond and watershed pond operations.

www.sweeneyfeeders.com/aquaculture.htm

What are some common methods of feeding fish?

• Demand feeders– Allow fish to bump

a rod and release feed when they are hungry.

– Used in raceways.– Fish must be

trained how to use them.

www.missourifishfarms.com/.../automatic_feeders.htm

What are some common methods of feeding fish?

• Auger feeding – Similar to systems

used by swine and poultry farmers.

– Feed stored in large tanks

– Moved by augers that drop feed in pond

– Common in tanks and raceways

www.ars-grin.gov/ars/PacWest/Aberdeen/overturf.htm

What does a feed label tells us?

• Fish farming utilizes prepared feeds.– A feed that is

produced by a feed mill and then sold in bags or bulk.

– Required to have a label.

What does a feed label tells us?

• Net weight• Product name• Brand name• Guaranteed analysis• Drug additives

www.ag.ohio-state.edu/~4hansc/2000minumumteachingrequirenmen...

What must the guaranteed analysis section contain?

• Minimum % of crude protein

• Maximum & minimum % of protein from non-protein nitrogen

• Minimum % of crude fat

• Maximum % of crude fiber

• Minimum and maximum % of salt and calcium

• Minimum % of phosphorus

• Other minerals• Vitamin content

What must be included on label if feed has drugs in it?

• The word “medicated”• Purpose of

medication must be stated.

• Directions and precautions for medication.

• Listing of all active drug ingredients.

www.gardenponds.com/fish.htm

Review / Summary

• What are the parts of the fish digestive system?

• What are some common methods of feeding fish?

• What does a fish label tell us?