Aquatic Plants and Animals

1. Aquatic Plants and Animals Chapter 2

2. US Aquatic Plant Species • Important in Asia • Europe and North America are dead last in plant production • Cultivate aquatic plants • Production of food, feed, and chemical products • Wastewater treatment • Biomass production for conversion to energy

6. Phycocolloid – carrageen – obtained from plants • Used in foods for gelling, thickening, and stabilizing • Phytoplankton • Primary producers • Photosynthesis – using sunlight and carbon dioxide to produce oxygen • Food source for zooplankton • Bloom – helps shade out unwanted rooted aquatic plants (pond fertilization)

7. US Aquatic Animal Species

13. Ornamental fish • Over 100 species • Occur in tropical – brackish water • Major industry in central Florida • Water temperature management – huge concern • Culturalists specialize in the production of colorful varieties • Sailfinmollies, guppies, clown barbs, black tetras, angelfish, and blue gouramies

14. Bullfrogs • Most come from wild • Used for consumption • Biological research – high demand compared to supply • Difficult to culture • Japanese and Taiwanese practice open pond culture of bullfrogs from eggs to adults

15. Alligators • Valued for meat and hide • Overhunted and habitat destruction reduced numbers • Extensive conservation efforts restored numbers – led to culture techniques (Texas, Georgia, South Carolina, Louisiana, and Florida) • Demand keeps prices high and production and profitable

16. Eels • Gourmet food in Japan, Taiwan, and European countries • Complicated life cycles • Spawn at sea and seed stock must be captured from wild – migrate upstream

17. Zooplankton • Copepods (small crustaceans) • Rotifers • Serve as vital food source for all fish • Primary consumers

18. Common Characteristics of Aquatic Species • Greater productive potential than terrestrial (land) plants and animals • Body temperature about same as environment • Energy used for growth • Body density similar to habitat • Energy to overcome gravity can be used for growth

19. Reduced energy required for getting food • Filter feeders – energy to growth • Efficient feed conversion • 1lb of gain for 1.5 to 2 lbs of feed • Rapid growth • Rate of 10%/day • Live in multidimensional environment • Polyculture • Floating cages,

20. Successful culture needs to consider • Reproductive habits • Major requirement • Stable supply of seed • Reproductive processes need to be understood • Genetic selection and improvement • Egg and larvae requirements • Female oyster – 500 million eggs per year • Crustaceans, crayfish – 500,000 to 1 million eggs • Nutritional needs and feeding habits • Low on food chain – uses low cost vegetable matter – carp, tilapia, and crawfish • High on food chain – more expensive high protein diet – shrimp, trout and bass • All needs met by aquatic environment

21. Polyculture possibilities • Depends on type of production system • Intensive systems – growth rate more a concern than efficiency of water space and nutrients • Increases total aquatic production in volume of water • Adaptability to crowding • Increases productivity of a space while increasing management for space • Disease resistance • Based on conditions at production sites • Market demand • Desired by consumers • Price consumers can afford • Prepared, easy-to-use forms of product • Storage to reach consumer • Desired flavor

23. Structures and Functions of Aquatic Animals and Plants • Animal surfaces • Dorsal – upper surface • Ventral – lower or abdominal surface • Anterior – applies to front or head • Posterior – tail or rear of animal

24. Morphology • Structure and form of fish • Herbivores • small upturned mouths – surface feeders like tilapia • Downturned mouths – bottom feeders like catfish • Homocercal • single-lobed tail fins – slow swimmers – thrive in water free of movement • Heterocercal • Forked tail fins – fast swimmers – thrive in flowing water

25. Body shape • Fusiform – long body tapered toward the end • Fast swimmers and need water space • Wide and flat or ventrally compressed • Stay on bottom and require lots of bottom space for growth • Laterally compressed • Rounded and thin from side to side • Hover in water

26. Physiology • Function of body • Skeletal system • Rigid framework – body shape and protect organs • Bony or hard material and cartilage • Internal (endoskeleton) or external (exoskeleton) • Muscular system • Provides movement for food and oxygen gathering and eliminating wastes • Digestive system • Converts feed into form for body maintenance, growth, and reproduction

27. Digestive system • Converts feed into form for body maintenance, growth, and reproduction • Assimilation – incorporation into the body • Mouth to anus • Vary according to diet • Herbivores – plants • Carnivores – animals • Omnivores – both plants and animals

28. Excretory system • Eliminates wastes • Kidneys, urinary ducts, urinary bladder, and urinary opening • Respiratory system • Takes in oxygen, delivers to tissues and cells, picks up carbon dioxide • Gills take in oxygen by diffusion • Circulatory system • Distributes blood throughout body

29. Nervous system • Supplies body with information about its environment • Impulses – electrical chemical changes • Sense organs or receptors • Sensory system • Five senses • Relays information through nervous system • Find food, identify predators, hearing, lateral lines that detect vibrations and motion

30. Reproduction system • Creating new organisms • Gametes – male and female sex cells • Zygote – fertilized egg • Incubation – period the zygote develops into a new organism • Some reproduce asexually

31. Anatomy • Anatomy of Finfish • Bony fish with hard calcium-based endoskeletons • Form and protects organs • Bony plates or scales – scales grow with fish • Digestive systems vary – herbivores have small stomach and long intestines – carnivores have large stomachs and short intestines • Well develop nervous systems – lateral line important to sensory organ – maintain balance and position • External fertilization • Gills remove oxygen from water – semipermeable –allows gases to pass through

32. Anatomy of Crustaceans • Shrimp, prawns, lobsters, crabs, crawfish • Exoskeleton of chitinous material • Polysaccharide of hexose proteins and inorganic salts • Protects and supports soft body • Decapods (10 legs) • Molting – shedding of old exoskeleton as it grows • 3 body segments • Head, • 2 pairs of antennae Mandibles or true jaws • two pairs of maxillae (little jaws) • Thorax • 3 pairs of jaw feet (hold food) • Large claws – protection and food getting • Last 4 – 2 tiny pincers at tip and 2 on claws • Abdomen • Swimmerets – egg attachment • Sixth swimmeret develops into a flipper or uropod for locomotion

33. Regeneration – regrowthof limbs • Internal anatomy • Simple circulatory, nervous, and excretory systems • Open circulatory system sinuses spaces that collect blood • Ear sacs aid in balance • Use gills to breathe • Life cycle and reproduction complex • Duct from testes or ovaries leads to outside to deposit sperm or eggs • Pandalids group of shrimp begin as males and after two years change to females

34. Anatomy of Mollusks • Bivalve – two shells – clams and oysters • Calcareous material – hard and resembles limestone • Adductor – muscles hold shells together • Muscular, hatchet-shaped foot  digging • Mantle lays over internal organs and secretes hard shell • Simple digestive and nervous system • Gills filter material from water – contains cilia • Siphon – water enters pass over gills and out another siphon via anus • Protandrous – change sex one or more times in their lives • Hermaphroditic – have gonads for both sexes • Gastropods have only one shell (snails, abalones)

35. Aquatic Plants • Make own food via photosynthesis (requires light and chlorophyll to convert carbon dioxide and water to sugar, oxygen, and water • Use stored energy by respiring – use energy for growth and reproduction • Algae: diatoms, desmoids, blue-green algae, euglena, volvox, and filamentous green algae, giant kelp • Reproduce asexually by spores – some produce gametes or sex cells • Fleshy corms of Chinese water chestnuts produce more corms – • Propagate by cuttings

36. Remove ammonia and nitrite wastes from water • Algae • Primitive plants without true roots, stems, or leaves • Filamentous algae form floating mats or hairlike strands (moss or pond scum) • Macrophytes • Vascular plants with true roots, stems, and leaves • Free-floating – tiny green plants (duckweed or watermeal) • Emergent – attached to bottom, but extend out of water (water lilies, or lotus) • Submergent – pondweed or hornwort are rooted and grow underwater • Marginal – very shallow water (cattails and bulrushes