Muscle, Hydrodynamics & Locomotion: Fish Biology Midterm II

Myomeres

W-shaped muscle blocks, that generate undulatory waves

Red Muscle

Highly vascularized relies on aerobic metabolism, slow contraction rate, fatigue resistant, specialized for sustained long-distance cruising (eg. Tuna)

White Muscle

Poorly vascularized, relies on Anaerobic metabolism, fast contraction rate. Specialized for short, high-velocity burst acceleration

Optimal Low-Drag Shape

Fusiform (streamlined teardrop) body shape minimizes combined frictional and form drag in fast swimmers

Reynolds Number Formula

Relative importance of inertial and viscous forces acting on a moving body such as a fish(Density x length x velocity / viscotiy)

to determine whether flow is laminar or turbulent

What does the Reynolds Number take into account?

Large R

Laminar flow

Low R

Turbulent Flow

Undulatory motion

wave-like body/fin motion (eels, some sharks, most larvae)

Oscillatory

paddling/swiveling fin motion on fixed axis

Sailfish

retracted dorsal and pelvic fins for stream-lined swimming, and extend these fins when chasing fins

Anguilliform

Backward swimming and tight crevice maneuvering (full body undulation)

Carangiform

High speed sustained cruisting (posterior third undulation)

Labriform

Braking, precise hovering and maneuvering (pectoral fin rowing/flapping)