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Biology 201 Dr. Edwin DeMont. Chapter 18 The Fishes: Vertebrate Success in Water Part 3. St. Francis Xavier University. Sensory Functions. Sensory receptors are widely distributed and used for olfaction, vision, hearing, equilibrium and for detecting water movements.
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Biology 201Dr. Edwin DeMont Chapter 18 The Fishes: Vertebrate Success in WaterPart 3 St. Francis Xavier University
Sensory Functions Sensory receptors are widely distributed and used for olfaction, vision, hearing, equilibrium and for detecting water movements. Schooling may be controlled by sensing water movement generated by nearby fish. Photo source St. Francis Xavier University
Lateral Line The lateral line system is a set of pits that detect changes in water pressure. Image source Shear forces in b.l. bend cupula Sense hairs bend and response initiated. Why is the lateral line located here? St. Francis Xavier University
Sound Production Audio communication is not obvious in fishes, but may be used extensively. Low frequency sounds can be detected by lateral line receptors. Picture Source White Grunt (Haemulon plumieri) More sounds St. Francis Xavier University
Buoyancy Control Several mechanisms aid in vertical regulation and include fins to create lift, changing body density by the addition of oils. Water pressure increases Swim bladders (s.b.) are also used for buoyancy. Volume of s.b. decreases Need to precisely control volume. Why? Density of fish increases St. Francis Xavier University
Buoyancy Control Two types of swim bladder: (1) no connection to gut and (2) direct connection to gut. 1. Physoclistous fishes 2. Physostomous fishes St. Francis Xavier University
Atlantic Herring Communication:- Reduced lateral line- Swim bladder connects to inner ear and gut. Photo source ‘Frt’ing Sound (at night) ContactAnti-predator (Fast Repetitive Tick) Photo source Research by B. Wilson St. Francis Xavier University