BIO325H5 Lecture 9: Metameric Myotomes & Fish Swimming
Document Summary
Myotomes: viscosity, reynold"s number, body waves, thrust of fish, snails, snakes. In addition, notochords may adjust function by means of dynamically variable mechanical properties (long) In the hagfish, the notochord not only functions in conjunction with the blocks of longitudinal muscle fibres for creation of body waves- it is also functioning as an internal amplification system. There is a median dorsal fin", a caudal fin", and a median ventral. Fin" (stabilizers)- all 3 are continuous to tip of tail. These are very different than the mobile shape-shifting fins of fish. A pair of metapleural folds run along the body, one on each side from the anterior to the antriopore (separate exit for filtered seawater) These structures should lend stability by avoiding rolling around the long axis (ie. tend to keep the dorsum up while swimming) The notochord is located just below the nerve chord, an intimate structural relationship because the nervous system co-ordinates body bending via the notochord.
