Fish locomotion

In addition, some fish can variously "walk" (i.e., crawl over land using the pectoral and pelvic fins), burrow in mud, leap out of the water and even glide temporarily through the air.

A lateral line system allows it to detect vibrations and pressure changes in water, helping the fish to respond appropriately to external events.

The subcarangiform group has a more marked increase in wave amplitude along the body with the vast majority of the work being done by the rear half of the fish.

Ocean sunfish, for example, have a completely different system, the tetraodontiform mode, and many small fish use their pectoral fins for swimming as well as for steering and dynamic lift.

[2] Rajiform locomotion is characteristic of rays and skates, when thrust is produced by vertical undulations along large, well developed pectoral fins.

[2] Diodontiform locomotion propels the fish propagating undulations along large pectoral fins, as seen in the porcupinefish (Diodontidae).

[2] Amiiform locomotion consists of undulations of a long dorsal fin while the body axis is held straight and stable, as seen in the bowfin.

In undulatory swimming modes, thrust is produced by wave-like movements of the propulsive structure (usually a fin or the whole body).

Oscillatory modes, on the other hand, are characterized by thrust produced by swiveling of the propulsive structure on an attachment point without any wave-like motion.

[2][11] Similar to adaptation in avian flight, swimming behaviors in fish can be thought of as a balance of stability and maneuverability.

[12] Because body-caudal fin swimming relies on more caudal body structures that can direct powerful thrust only rearwards, this form of locomotion is particularly effective for accelerating quickly and cruising continuously.

[2][11] body-caudal fin swimming is, therefore, inherently stable and is often seen in fish with large migration patterns that must maximize efficiency over long periods.

As a result, median-paired fin swimming is well adapted for high maneuverability and is often seen in smaller fish that require elaborate escape patterns.

[2] Zebrafish have even been observed to alter their locomotor behavior in response to changing hydrodynamic influences throughout growth and maturation.

[15] The transition of predominantly swimming locomotion directly to flight has evolved in a single family of marine fish, the Exocoetidae.

Of the 64 extant species of flying fish, only two distinct body plans exist, each of which optimizes two different behaviors.

[17] Because flying fish are primarily aquatic animals, their body density must be close to that of water for buoyancy stability.

[16] In the biplane or Cypselurus body plan, both the pectoral and pelvic fins are enlarged to provide lift during flight.

[16] These fish also tend to have "flatter" bodies which increase the total lift-producing area, thus allowing them to "hang" in the air better than more streamlined shapes.

[17] As a result of this high lift production, these fish are excellent gliders and are well adapted for maximizing flight distance and duration.

Flying fish with a monoplane body plan demonstrate different launching behaviors from their biplane counterparts.

Instead of extending their duration of thrust production, monoplane fish launch from the water at high speeds at a large angle of attack (sometimes up to 45 degrees).

Able to spend longer times out of water, these fish may use a number of means of locomotion, including springing, snake-like lateral undulation, and tripod-like walking.

The mudskippers are probably the best land-adapted of contemporary fish and are able to spend days moving about out of water and can even climb mangroves, although to only modest heights.

[32] There is also a negative correlation between the fineness ratio (length of body to maximum width) and the swimming ability of reef fish larvae.

[35] Small undulatory swimmers such as fish larvae experience both inertial and viscous forces, the relative importance of which is indicated by Reynolds number (Re).

As in fishes which swim in viscous or high-friction flow regime, would create high body drag which will lead to higher Strouhal number.

Sensitivity of larval fish to velocity and flow fields provides the larvae a critical defense against predation.

Behavior represents the unique interface between intrinsic and extrinsic forces that determine an organism's health and survival.

[44] Acute ethanol exposure reduce visual sensitivity of larvae causing a latency to respond in light and dark period change.

Fish, like these yellowfin tuna , use many different mechanisms to propel themselves through water
Fins used for locomotion: (1) pectoral fins (paired), (2) pelvic fins (paired), (3) dorsal fin , (4) adipose fin, (5) anal fin, (6) caudal (tail) fin
Skeletal anatomy of Tilapia [ 3 ]
Like a plane or submarine, a fish has six degrees of freedom .
Eels propagate a more or less constant-sized flexion wave along their slender bodies.
Tunas such as the bluefin swim fast with their large crescent-shaped tails.
A bright yellow boxfish swims with its pectoral fins only.
Boxfish use median-paired fin swimming, as they are not well streamlined, and use primarily their pectoral fins to produce thrust.
Porcupine fish (here, Diodon holocanthus ) swim by undulating their pectoral fins.
Gymnotus maintains a straight back while swimming to avoid disturbing its electric sense .
Sharks are denser than water and must swim continually to maintain depth, using dynamic lift from their pectoral fins.
Sardines use body-caudal fin propulsion to swim, holding their pectoral, dorsal, and anal fins flat against the body, creating a more streamlined body to reduce drag.
flying fish.
Flying fish gain sufficient lift to glide above the water thanks to their enlarged pectoral fins.
illustration of a typical flying fish body plan
In the monoplane body plan of Exocoetus , only the pectoral fins are abnormally large, while the pelvic fins are small.
Alticus arnoldorum hopping
Alticus arnoldorum climbing up a vertical piece of Plexiglas
Salmon larva emerging from its egg