swimming & locomotion
DESCRIPTION
Swimming & Locomotion. Major types of locomotion in fishes. Walking frogfishes Crawling sea robins Swimming most fishes. Antennariidae warty frogfish Antennarius maculatus. The swimming mechanism. Muscles Propulsive waves. Swimming modes. Body musculature. Fin musculature. - PowerPoint PPT PresentationTRANSCRIPT
Swimming & Locomotion
Major types of locomotion in fishes
• Walking – frogfishes
• Crawling – sea robins
• Swimming– most fishes
Antennariidaewarty frogfishAntennarius maculatus
The swimming mechanism
• Muscles• Propulsive waves
Swimming modes
Body musculature
Fin musculature
Swimming modes (body musculature)
Swimmingmodes
Swimming examples
Thunniform – Carangiform swimming
Labriform swimming
Musculature myotomes
Epiaxial or dorsalmuscles
hypaxial or ventralmuscles
Red
Distribution of red muscle
Distribution of red muscle
Ectothermfishes
Bluefin tuna
Skipjack tuna Mako shark
Red muscle
Propulsive wave•Progressive tailward passage•Push force•Reactive force•Forward thrust component•Lift or slippage component
P
R L
T
Progressive swimming undulation wave
Thrust - DragGravity - Lift + Buoyancy
Swimming Forces
Lift Force
• Static lift– Swim bladder– Lipids / Oils
• Dynamic Lift– Pectoral fin rotation– Pectoral hydrofoil shape
Drag forces I
• Frictional or Viscous Drag– Boundary layer: non-moving water layer
that creates friction with surrounding water
– Not speed related– To reduce frictional drag:
• Mucous• Reduction surface area• Ctenoid scales• Placoid scales
Frictional Drag (Flow separation)
Placoid scales
Ctenoid scales
Drag forces II
• Pressure or Inertial Drag– Caused by pressure differences– Drag increases with speed– To reduce pressure drag:
• Streamline shape– Width-length ratio = 0.25– Thickest cross-section 2/5 from mouth– Long and narrow wing-like pectoral fins for lift– Body depressions for retracting paired & median
fins
Pressure and frictional drag
High speed streamlined fishes
Caudal keel
ScombridaeBigeye tunaThunnus obesus
Caudal fin shapes high aspect ratio (thunniform
swimming)
CarangidaeJacks
Caranx melampygus
Caudal fin shapes high/medium aspect ratio (carangiform
swimming)
SerranidaeNassau grouperEpinephelus striatus
Caudal fin shapes low aspect ratio (subcarangiform
swimming)
EsocidaeNorthern pikeEsox lucius
Caudal fin shapes low aspect ratio (subcarangiform
swimming)