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30-2 Fishes. BIO 1004 Flora. What is a Fish?. Aquatic vertebrate Paired fins, scales and gills Function of parts Gills – respiration Scales – protection Fins - movement. Fish Anatomy/Feeding. Types of feeders includes: Herbivores Carnivores Omnivores Parasites Filter feeders
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30-2 Fishes BIO 1004 Flora
What is a Fish? • Aquatic vertebrate • Paired fins, scales and gills • Function of parts • Gills – respiration • Scales – protection • Fins - movement
Fish Anatomy/Feeding • Types of feeders includes: • Herbivores • Carnivores • Omnivores • Parasites • Filter feeders • detritivores
Fish Anatomy • Pyloric ceca – specialized structure in fish that helps them further digest food • Gills – site of gas exchange • Made of structures called filaments • Filaments have a rich supply of blood through capillaries are attached • Breath oxygen rich water through mouth, pump it across gills, and breath out oxygen poor water through openings in the pharynx ** Operculum protects the gills
Anatomy Cont. • Circulation • Have a closed circulatory system with a heart • Single loop system • Heart has 3 chambers • Sinus venosus, atrium, bulbusarteriosus (includes ventricle) • SV, A, V, BA, gills, body, back to SV
Response • Well developed nervous system • Most fish have highly developed sense organs • Have color vision as good as our own • Lateral line system – detects gentle currents and vibrations in the water with sensory receptors
Movement • Muscle contract on one side of body or other and causes s-shaped curve to move down body • Most fish bodies are more dense that the water around them (sink) • Fish are equipped with swim bladders, which is a gas filled organ, that adjusts their buoyancy. • Located just beneath backbone
Reproduction • Eggs of fishes are fertilized externally or internally (depending on species) • Fishes whose eggs hatch outside their body are called “oviparous” • Fishes whose eggs stay inside a mom’s body after fertilization is called “ovoviviparous” • Viviparous – obtain nutrients from mother - not a yolk sac • Also born alive
Groups of Fishes • Jawless • No teeth or true jaws • Lack vertebrae • Ex: lampreys or hag fishes • Sharks/relative of sharks • Skeletons are built entirely of cartilage, not bone • Scales (rough) • Lots of teeth • Bony fishes • Skeletons are made of hard calcified bone