WILD 3580 1st Edition Lecture 10 Outline of Last Lecture I Gnathostomata Advantages II Early Gnathostomes III Modern Boney Fish IV Characteristics of Most Teleosts V Natural History of Fish Outline of Current Lecture I Respiration II Buoyancy Regulation III Gas Release Addition IV Sound reception V Locomotion Current Lecture I II Respiration Evolved to get oxygen out of water efficiency through countercurrent exchange High to low gradient between water and blood Gill filaments increase surface area Primary and secondary lamellae hold gill filaments Only functions when water is moving across the gills o Gill pumping synchronized pressure changes in the buccal mouth and opercular gills chamber s Creates a pressure lower in the operculum so water can flow out o RAM Ventilation mouth open while swimming Fish that don t have operculum ex Sharks Some fish obtain oxygen through aerial respiration o Aerial respiration O2 from the atmosphere Places were fish live in poor oxygenated water Ex Lungfish These fish are called facultative air breathers use atmospheric O2 as a supplement optional Obligate air breathers must have access to atmospheric O2 Organs lung like structures skin swim bladder Buoyancy Regulation Very energetically expensive These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute III IV V Fish have adaptations to maintain balance in the water column o Swim Gas bladder a flexible gas filled chamber in the body cavity Fish that remain mostly in the bottom of the water they have none or small gas bladders Forms as an out pocket of the esophagus during embryonic development Pneumatic duct connect the bladder to the esophagus and is a condition called physostomous gas bladder fish who breath atmospheric O2 Physoclistous gas bladder conditions pneumatic duct not retained Maintain position in the water column increase volume increase buoyancy Neutrally buoyant maintaining a position in the water column without expending energy Functions buoyancy regulation respiration sound reception Gas Release Addition Physostomes release gas through the esophagus Physoclists release gas through the bloodstream o Oval body high vascularized part of the gas bladder capillaries to move release gases Adding gases involves moving gases from the blood to the oval body o Gas gland part of the gas bladder that contains a rete mirable system veins and arteries lying adjacent to each other but flowing in opposite directions Sound Reception Otoliths ear stone fish usually have 3 to hear o Non compressed sound waves because they are o the same densities o Otoliths are different densities to convert sound waves into movement o Balance equilibrium o Can determine age of fish Gas bladder can be used to enhance hearing Weberianossicles series of bones connects gas bladder to otoliths Locomotion How an animal moves through its environment Fish move through an aquatic median Energetically expensive fish are efficient o Body shape long relative to its depth 1 4 stream like 25 of length Most efficient is fusiform shaped fish that rely on speed
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