Aquaculture Science Chapter 4 Study/Review Management Practices for Finfish

Question 1. Sexual reproduction involves the production of eggs from testes and sperm from the ovaries. False Eggs come from the ovaries and sperm comes from the testes.

Question 2 With a permit, predatory birds can be killed around fish ponds. True

Question 3. Humans stealing fish from ponds can become a problem. True

Question 4. Management is the secret ingredient to successful aquaculture True

Question 5. The color of the water controls spawning time in catfish. False Temperature controls spawning

Question 6. Channel catfish spawn on spawning mats. False They spawn in nests or spawning containers

Question 7. Oxygen levels of 5 ppm are lethal for fish. False Lethal levels start at 1 ppm.

Question 8. Rainbow trout hatch in freshwater, swim to saltwater, mature, and return to fresh water. False Salmon do this.

Question 9 Water temperatures above 75degrees F are lethal for trout. True

Question 10. Hatching rate depends on water temperature. True

Question 11. Give the scientific name for the majority of cultured catfish. Ictalurus punctalus

Question 12. When do catfish spawn? Water temp. is degrees F In the Wild – early February to Late August Peak time in May

Question 13 Besides fertilizing the eggs, what role does the male catfish play? With his fins, he fans the eggs to provide oxygen and removes waste products.

Question 14 What is the optimum temperature for growing catfish? 85 degrees F

Question15 At what weight are catfish harvested? Usually at 1.25 pounds.

Question 16 Name three types of incubators used for trout. California trays Vertical trays Heath Upwelling Flatbottom

Question 17 In a trout hatchery, how many fry can be stocked in a trough 10 feet long, and 18 inches wide with 3 to 4 inches of water? About 30,000 fry.

Question 18 What two things should be considered when selecting a species of tilapia? Growth rate Cold tolerance

Question 19 Tilapia are native to what parts of the world? Africa Middle East

Question 20 What is the major problem associated with pond culture of tilapia? Uncontrolled population

Question 21 At what size can tilapia reach sexual maturity? 50 to 100 gm.

Question 22 Trout grow best in water temperature of: C degrees F

Question 23 Name three types of incubators systems used in fish culture. California trays Vertical Tray Heath incubators Upwelling incubators

Question 24 Trout fry are fed when 50 percent _______ _______. Swim up

Question 25 Most trout are commercially raised in _______, whereas most catfish are commercially raised in _______. Raceway, ponds

Question 26 The process of adding oxygen to a pond or raceway is called _______. Aeration.

Question 27 Which of the following do not affect the carrying capacity of a trout production facility? B. concrete thickness

Question 28 How much time is required to raise market-size hybrid striped bass? Two years or two growing seasons.

Question 29 Grass carp, silver carp, and bighead carp are native to what continent? Asia (China)

Question 30 Name three hormones involved in the natural spawning process. Gonadotropic hormone Testosterone Estrogen Progesterone

Question 31 Name two ways to increase spawning frequency Modify the genetics Change the environment Inject with hormones

Question 32 What effect does temperature have on the development of fertilized eggs? When temperature increases, development time decreases. When temperature decreases, development time increases.

Question 33 Name four baitfish Goldfish Golden shiner Fathead minnow White sucker topminnows

Question 34 What is the most common use for crappies? Sport fishing Many pond and lake owners stock crappie fingerlings.

Question 35 Name four common ornamental fish. Guppy Swordtail Angelfish Sailfin Molly Zebra danio

Question 36 Develop a list of fish that would be stressed if the water turned cold. Catfish Tilapia Some baitfish Most hobby or tropical fish

Question 37 List three breeding techniques for improving any aquatic species. Selective breeding Hybridization Crossbreeding

Question 38 Why would a producer consider raising tilapia in a male monoculture culture? This environment would prevent uncontrolled reproduction and allow all tilapia to grow at the same rate to a marketable size.

Question 39 Describe two polyculture systems using tilapia. Tilapia and catfish Tilapia and prawns – prawns will eat the fish waste.

Question 40 Describe three methods of fertilizing a tilapia pond for increased production Use inorganic fertilizers By raising pigs, chickens, or ducks and having waste drop into pond. Use organic plants chopped up

Question 41 How are hybrid striped bass produced? Crossbreeding of the striped bass and the white bass.

Question 42 Describe why an understanding of sex determination is important. Once sex determination is understood, this knowledge can be used to produce monosex cultures of fish.

Question 43 What does it mean to harvest fish by topping? Harvesting only the larger fish, and letting the smaller ones escape through the seine or net.

Question 44 Give three reasons why culturing fish increases the concern for disease. Intense culture puts fish in close contact which makes disease spread much easier.Animals may be under stress and water quality can deteriorate rapidly.

Question 45 Define flow and density indexes. Flow index = (fish weight)/(fish length x water inflow). Density Index = (weight of fish)/(fish length x volume of rearing unit)

Question 46 Compare salmon ranching to salmon farming. Ranchers – raise to migratory size in freshwater – then release into rivers. When return they catch and market. Farmers – 6” to market size.

Question 47 Give three reasons why tilapia are not widely available in the United States. Low tolerance to low temperature Few markets Market size is hard to attain because of early maturity.

Question 48 Explain why grading or sorting is necessary for hybrid striped bass culture. Prevents cannibalism.

Question 49 Suggest two reasons why carp culture is dominant in countries other than the United States, especially Asia. Carp are native to Asia Considered trash fish in US

Question 50 Define a hybrid and give two examples. Crosses of different species Hybrid stripped bass Reddish-orange tilapia

Aquaculture Chapter 4 Review