Fish Locomotion Definition The result of interactions between

Fish Locomotion

Definition • The result of interactions between the fish’s body shape, anatomy, physiology, behavior, and the behavior of water

Properties of Water • A). Cohesion • B). Adhesion • C). Density/Viscosity • D). High Specific Heat • E). High Heat of Vaporization • F). Other Properties

A). Cohesion • Attraction between particles of the same substance • Water molecules attracted to other water molecules • Surface tension, a measure of the strength of water’s surface, is the direct result of cohesion.

Surface Tension Cohesion and surface tension is why this hurts!

Cohesion • Surface tension of water decreases significantly with temperature. • Hot water is a better cleaning agent because the lower surface tension makes it a better "wetting agent" (doesn’t stick to itself as well)

A). Cohesion Gyrinid Beetles Water Striders

A). Cohesion • Basilisk lizard – Light weight (2 grams) upon hatching to more 200 grams) as adults – Run across water for a distance of approximately 15 feet (4. 5 meters) • Called the “Jesus lizard” in Central America

B). Adhesion • Attraction between two different substances. – Water will make hydrogen bonds with other surfaces • Glass, soil, plant , tissues, and cotton – Turbid/muddy – Capillary action

Adhesion and fish • Two types of drag • 1: Friction (skin or viscous) drag—results from water sticking to fish as it tries to move through the fluid. – More surface area, more water can stick

F). Viscosity • Viscosity – Resistance to change in form • Molasses has high viscosity – Relatively incompressible – ~ 50 greater than air – 800 x more dense than air – Viscosity also decreases with increasing temperature • hydrogen bonds – Movement is more energetically expensive

Water dynamitics and fish • Pressure (form) drag—results from displacement of water mass as fish moves through the fluid. • “Hole” from negative pressure

Reduction of drag • Minimize the amount of water displaced • Two ways fish can reduce these – Pressure: more streamlined – Friction: reduce surface area, reduce friction, or promote turbulent flow near body

What is the optimal body shape for fish?

Webb’s functional morphology plane Accelerators Cruisers Maneuverers

Acceleration specialists. Adaptations for busts of speed Flexible, Torpedo-Like Body Ventrally-placed Pectoral Fin Small Pectoral and Pelvic fins relative to body size Posterior-placed Median Fins (Dorsal and Anal) Thick Caudal Peduncle

Maneuvering Specialists – Adaptations for structure living Laterally Compressed Body: Gibbose Large Fins Relative To Body Size Fins Evenly Distributed Laterally Positioned Pectoral Fins; large relative to body

Cruisers: Adaptations for roving or current Fusiform, Streamlined body Horizontally Positioned Pectoral Fins Forked Tail, Narrow or Average Peduncle Relatively large caudal fin

Other body shapes • Filiform/angilliform – Eel like, borrowing • Dorso-ventrally compressed – Benthic and often in high flow

Case studies

What about intraspecific variation? • Lentic vs lotic habitats? • Predation?

Body Musculature • Trunk musculature • Myotomes or myomeres - series of muscle blocks • Myosepta - sheets of connective tissue separating myomeres – Myotomes are folded, outer edges resemble a “W”

Body Musculature • Trunk musculature – A horizontal septum separates upper and lower muscle masses • 40 -60% of fish weight is muculature • Upper muscles are called epaxial muscle • Lower muscles are called hypaxial muscles

Chinook Salmon Lamprey/Hagfish

Fish Muscles • 3 types – Red, pink, and white • Most have a combo of 2 or 3 types • What makes the red muscles red? • A lot of capillaries Tuna

Muscles – White muscle - majority of post cranial muscles in most fishes – Thicker muscle fibers than red muscle (300 m) – Used anaerobically in short-duration burst swimming (fast fibers) » fatigues quickly

Muscles – White muscle – Lacks myoglobin; little vascularization; limited oxygen supply – Energy results from anaerobic glycolysis » Works for short periods of time » Quick bursts of movement – Produces large amounts of lactate; requires a long time for muscle recovery

Muscles • Red muscle - thin, lateral, superficial sheet under the skin between the epaxial and hypaxial muscle masses – Smaller muscle fibers than white (50 - 150 m) – Infused with capillaries (hemoglobin and myoglobin)

Muscles • Red muscle – Continuous (aerobic) swimming • Rich oxygen supply – Abundant, large mitochondria; energy supplied by aerobic oxidation of lipids; fast recovery of muscles

Red Muscle Red: by cross-section, 5 to 15 % muscle mass in most species (some species 0 % while others + 15 %)

The Tuna: A Swimming Machine • Never stop swimming • Cover vast distances – 7, 000 miles! – Northern bluefin cross Atlantic in 119 days (40 miles/day) • Endurance swimmers • Capable of high speed bursts • It’s all about the adaptations. . .

Muscles • Pink muscle - contains fibers intermediate in character between those of white and red muscle – Used at intermediate swimming velocities • Too high for red muscle to sustain but too low for effective use of white muscle • Aerobic – Mosaic muscles - salmonids have red and pink muscle fibers mixed with white fibers – Used by smolts during migration to sea

Red Muscle vs. White Muscle Red White Rate of fatigue Slow Fast Muscle performance Efficiency Power Type of Swimming Slow Cruising Fast Bursts Capillary beds Extensive Sparse Muscle Fiber Density Low High Muscle Mass High Low

Fish Locomotion

Moving Through Water • Functions of Fins – Caudal fin: propulsion (oscillatory and undulatory), rudder – Dorsal and anal fins: undulatory propulsion and prevents roll – Pelvic fins: controls pitch – Pectoral fins: propulsion (sculling) and control yaw; also control turning and brakes

Moving Through Water Body/Caudal Fin (BCF) Locomotion Undulation = waves passing down body or fin Oscillation = flapping motion

Modes of locomtion • Propulsion by body and/or caudal fin • Propulsion by undulation of median or pectoral fins • Non-swimming locomotion

Moving Through Water • Body/Caudal Fin (BCF) Locomotion – Anguilliform • Large side-to-side amplitude of the wave along the whole body • Purely undulatory, most of the body participates

Moving Through Water • Body/Caudal Fin (BCF) Locomotion – Subcarangiform • Similar to anguilliform – Posterior half of the body • Anterior portion of the body often rounded or thick – Anterior portion low flexibility – Posterior undulations • Caudal fin rounded, truncate, or emarginate – Trout, cods, basses

Moving Through Water • Body/Caudal Fin (BCF) Locomotion – Carangiform • Posterior body flexes • Anterior 1/2 or 2/3 body inflexible – Narrow caudal peduncle • Posterior portion of body tapers – Caudal fin forked or lunate=(half moon) • High aspect ratio – Herrings, sardines, some jacks and some mackerals

Moving Through Water • Body/Caudal Fin (BCF) Locomotion – Thunniform • Most efficient locomotion mode (but few species) • High cruising speeds to be maintained for long periods. • Significant lateral movements occur only at the caudal fin and area near the narrow peduncle • Stiff caudal fins – Aspect ratio (4 -10)! • Marlins, sailfishes, Lamnid sharks, tunas

Moving Through Water • Body/Caudal Fin (BCF) Locomotion – Ostraciform • Oscillation of the caudal fin • Assisted with pectoral fins

Moving Through Water • Median/Paired Fin (MPF) Locomotion – Diodontiform: achieved by passing undulations down broad pectoral fins – Amiiform: done by undulations of a (usually long-based) dorsal fin, while the body axis is often held straight when swimming – Gymnotiform: propulsion is by undulations of a long-based anal fin – Balistiform: both the anal and dorsal fins undulate to generate the propulsion forces

Modes of Swimming

Aspect ratio tail height: tail depth High AR Low AR = efficiency, speed large thrust w/ low drag

Fins

Bernal et al. 2001

Do all fish swim?

Non-swimming Locomotion • Jet propulsion - water exhaled from the gill chambers; anglerfishes • Terrestrial locomotion - fish can employ anguilliform motion over land • Walking - batfishes • Burrowing - eels, mudminnows • Jumping - tarpon, manta rays • Gliding - flying fish • Flying - freshwater hatchetfishes, freshwater butterflyfish