Locomotion

@article{garrod1874animal,
    author = "GARROD, A. H.",
    title = "Animal Locomotion; or, Walking, Swimming, and Flying",
    year = "1874",
    journal = "Nature",
    url = "https://doi.org/10.1038/009221a0",
    doi = "10.1038/009221a0",
    number = "221",
    openalex = "W1993018585",
    pages = "221-222",
    volume = "9"
}

@misc{muybridge1887animals17,
    author = "Muybridge, E",
    title = "Animals in Motion",
    year = "1887",
    howpublished = "New York, Dover Books [1957]",
    note = "talkorigins\_source = {true}; raw\_reference = {Muybridge, E., 1887, Animals in Motion: New York, Dover Books [1957].}"
}

@misc{gregory1912notes11,
    author = "Gregory, W. K",
    title = "Notes on the principles of quadrupedal locomotion and the mechanisms of the limbs in hoofed animals",
    year = "1912",
    howpublished = "Annals of the New York Academy of Sciences, v. 22, p. 267-292",
    note = "talkorigins\_source = {true}; raw\_reference = {Gregory, W. K., 1912, Notes on the principles of quadrupedal locomotion and the mechanisms of the limbs in hoofed animals: Annals of the New York Academy of Sciences, v. 22, p. 267-292.}"
}

@article{orton1913the18,
    author = "Orton, J. H",
    title = "The ciliary mechanisms on the gill and the mode of feeding in Amphioxus, Ascidians and Solenomyo togato",
    year = "1913",
    journal = "Journal of the Marine Biological Association of the United Kingdom, v. 10, p. 19-49",
    note = "talkorigins\_source = {true}; raw\_reference = {Orton, J. H., 1913, The ciliary mechanisms on the gill and the mode of feeding in Amphioxus, Ascidians and Solenomyo togato: Journal of the Marine Biological Association of the United Kingdom, v. 10, p. 19-49.}"
}

@article{gray1936studies8,
    author = "Gray, J",
    title = "Studies in animal locomotion VI. The propulsive powers of the dolphin",
    year = "1936",
    journal = "Journal of Experimental Biology, v. 13, p. 192-199",
    note = "talkorigins\_source = {true}; raw\_reference = {Gray, J., 1936, Studies in animal locomotion VI. The propulsive powers of the dolphin: Journal of Experimental Biology, v. 13, p. 192-199.}"
}

@article{harris1936the12,
    author = "Harris, J. E",
    title = "The role of fins in the equilibrium of the swimming fish I. Wind-tunnel tests on a model of Mustelus canis (Mitchill)",
    year = "1936",
    journal = "Journal of Experimental Biology, v. 13, p. 476-493",
    note = "talkorigins\_source = {true}; raw\_reference = {Harris, J. E., 1936, The role of fins in the equilibrium of the swimming fish I. Wind-tunnel tests on a model of Mustelus canis (Mitchill): Journal of Experimental Biology, v. 13, p. 476-493.}"
}

@article{harris1938the13,
    author = "Harris, J. E",
    title = "The role of fins in the equilibrium of the swimming fish II. The role of the pelvic fins",
    year = "1938",
    journal = "Journal of Experimental Biology, v. 13, p. 476-493",
    note = "talkorigins\_source = {true}; raw\_reference = {Harris, J. E., 1938, The role of fins in the equilibrium of the swimming fish II. The role of the pelvic fins: Journal of Experimental Biology, v. 13, p. 476-493.}"
}

@book{howell1944speed14,
    author = "Howell, A. B",
    title = "Speed in Animals",
    year = "1944",
    publisher = "Chicago, University of Chicago Press",
    note = "talkorigins\_source = {true}; raw\_reference = {Howell, A. B., 1944, Speed in Animals: Chicago, University of Chicago Press.}"
}

Abstract The swimming of long animals like snakes, eels and marine worms is idealized by considering the equilibrium of a flexible cylinder immersed in water when waves of bending of constant amplitude travel down it at constant speed. The force of each element of the cylinder is assumed to be the same as that which would act on a corresponding element of a long straight cylinder moving at the same speed and inclination to the direction of motion. Relevant aerodynamic data for smooth cylinders are first generalized to make them applicable over a wide range of speed and cylinder diameter. The formulae so obtained are applied to the idealized animal and a connexion established between B/λ, V/U and R1. Here B and λ are the amplitude and wave-length, V the velocity attained when the wave is propagated with velocity U, R1 is the Reynolds number Udρ/μ, where d is the diameter of the cylinder, ρ and μ are the density and viscosity of water. The results of calculation are compared with James Gray’s photographs of a swimming snake and a leech. The amplitude of the waves which produce the greatest forward speed for a given output of energy is calculated and found, in the case of the snake, to be very close to that revealed by photographs. Similar calculations using force formulae applicable to rough cylinders yield results which differ from those for smooth ones in that when the roughness is sufficiently great and has a certain directional character propulsion can be achieved by a wave of bending which is propagated forward instead of backward. Gray’s photographs of a marine worm show that this remarkable method of propulsion does in fact occur in the animal world.

@article{doi101098rspa19520159,
    author = "Taylor, Geoffrey Ingram",
    title = "Analysis of the swimming of long and narrow animals",
    year = "1952",
    journal = "Proceedings of the Royal Society of London A Mathematical and Physical Sciences",
    abstract = "Abstract The swimming of long animals like snakes, eels and marine worms is idealized by considering the equilibrium of a flexible cylinder immersed in water when waves of bending of constant amplitude travel down it at constant speed. The force of each element of the cylinder is assumed to be the same as that which would act on a corresponding element of a long straight cylinder moving at the same speed and inclination to the direction of motion. Relevant aerodynamic data for smooth cylinders are first generalized to make them applicable over a wide range of speed and cylinder diameter. The formulae so obtained are applied to the idealized animal and a connexion established between B/λ, V/U and R1. Here B and λ are the amplitude and wave-length, V the velocity attained when the wave is propagated with velocity U, R1 is the Reynolds number Udρ/μ, where d is the diameter of the cylinder, ρ and μ are the density and viscosity of water. The results of calculation are compared with James Gray’s photographs of a swimming snake and a leech. The amplitude of the waves which produce the greatest forward speed for a given output of energy is calculated and found, in the case of the snake, to be very close to that revealed by photographs. Similar calculations using force formulae applicable to rough cylinders yield results which differ from those for smooth ones in that when the roughness is sufficiently great and has a certain directional character propulsion can be achieved by a wave of bending which is propagated forward instead of backward. Gray’s photographs of a marine worm show that this remarkable method of propulsion does in fact occur in the animal world.",
    url = "https://doi.org/10.1098/rspa.1952.0159",
    doi = "10.1098/rspa.1952.0159",
    openalex = "W2008949258"
}

@misc{gray1957how9,
    author = "Gray, J",
    title = "How fishes swim",
    year = "1957",
    howpublished = "Scientific American, v. 197, p. 48-54",
    note = "talkorigins\_source = {true}; raw\_reference = {Gray, J., 1957, How fishes swim: Scientific American, v. 197, p. 48-54.}"
}

The paper seeks to determine what transverse oscillatory movements a slender fish can make which will give it a high Froude propulsive efficiency, $\frac{\hbox{(forward velocity)} \times \hbox{(thrust available to overcome frictional drag)}} {\hbox {(work done to produce both thrust and vortex wake)}}.$ The recommended procedure is for the fish to pass a wave down its body at a speed of around $\frac {5} {4}$ of the desired swimming speed, the amplitude increasing from zero over the front portion to a maximum at the tail, whose span should exceed a certain critical value, and the waveform including both a positive and a negative phase so that angular recoil is minimized. The Appendix gives a review of slender-body theory for deformable bodies.

@article{doi101017s0022112060001110,
    author = "Lighthill, M. J.",
    title = "Note on the swimming of slender fish",
    year = "1960",
    journal = "Journal of Fluid Mechanics",
    abstract = "The paper seeks to determine what transverse oscillatory movements a slender fish can make which will give it a high Froude propulsive efficiency, $\frac{\hbox{(forward velocity)} \times \hbox{(thrust available to overcome frictional drag)}} {\hbox {(work done to produce both thrust and vortex wake)}}.$ The recommended procedure is for the fish to pass a wave down its body at a speed of around $\frac {5} {4}$ of the desired swimming speed, the amplitude increasing from zero over the front portion to a maximum at the tail, whose span should exceed a certain critical value, and the waveform including both a positive and a negative phase so that angular recoil is minimized. The Appendix gives a review of slender-body theory for deformable bodies.",
    url = "https://doi.org/10.1017/s0022112060001110",
    doi = "10.1017/s0022112060001110",
    openalex = "W2014546372"
}

@inproceedings{bainbridge1961problems1,
    author = "Bainbridge, R",
    title = "Problems of fish locomotion",
    year = "1961",
    booktitle = "Symposium of the Zoological Society, London, v. 5, p. 13-32",
    note = "talkorigins\_source = {true}; raw\_reference = {Bainbridge, R., 1961, Problems of fish locomotion: Symposium of the Zoological Society, London, v. 5, p. 13-32.}"
}

@misc{gray1968animal10,
    author = "Gray, J",
    title = "Animal Locomotion",
    year = "1968",
    howpublished = "London, Weidenfield and Nicolson",
    note = "talkorigins\_source = {true}; raw\_reference = {Gray, J., 1968, Animal Locomotion: London, Weidenfield and Nicolson.}"
}

Abstract The elongated-body theory of the reactive forces on a fish moving in water (that is, forces resulting from the inertia of associated water movements) is extended so that a prediction of instantaneous reactive force between fish and water is obtained for fish motions of arbitrary amplitude, regular or irregular (§2). A preliminary application of the theory to the balance of reactive thrust and resistive drag in regular carangiform swimming of fishes with slender caudal fins is made (§3). Comparison with data (Bainbridge 1963) on the dace Leuciscus suggests that an important feature of this balance may be a substantial enhancement of drag for such fishes when swimming movements commence, an enhancement here interpreted in terms of a boundary-layer-thinning mechanism first suggested by Dr Quentin Bone.

@article{doi101098rspb19710085,
    author = "Lighthill, M. J.",
    title = "Large-amplitude elongated-body theory of fish locomotion",
    year = "1971",
    journal = "Proceedings of the Royal Society of London. Series B, Biological sciences",
    abstract = "Abstract The elongated-body theory of the reactive forces on a fish moving in water (that is, forces resulting from the inertia of associated water movements) is extended so that a prediction of instantaneous reactive force between fish and water is obtained for fish motions of arbitrary amplitude, regular or irregular (§2). A preliminary application of the theory to the balance of reactive thrust and resistive drag in regular carangiform swimming of fishes with slender caudal fins is made (§3). Comparison with data (Bainbridge 1963) on the dace Leuciscus suggests that an important feature of this balance may be a substantial enhancement of drag for such fishes when swimming movements commence, an enhancement here interpreted in terms of a boundary-layer-thinning mechanism first suggested by Dr Quentin Bone.",
    url = "https://doi.org/10.1098/rspb.1971.0085",
    doi = "10.1098/rspb.1971.0085",
    openalex = "W2032519784",
    references = "openalexw3209569680"
}

@article{webb1973the23,
    author = "Webb, J. E",
    title = "The role of the notochord in forward and reverse swimming and burrowing in the amphioxus Branchiostoma lanceolatum",
    year = "1973",
    journal = "Journal of Zoology, London, v. 170, p. 325-338",
    note = "talkorigins\_source = {true}; raw\_reference = {Webb, J. E., 1973, The role of the notochord in forward and reverse swimming and burrowing in the amphioxus Branchiostoma lanceolatum: Journal of Zoology, London, v. 170, p. 325-338.}"
}

@inproceedings{mackie1974branchial15,
    author = "Mackie, G. O. and Paul, D. H. and Singla, C. M. and Sleigh, M. A. and Williams, D. E",
    title = "Branchial innervation and ciliary control in the ascidian Corella",
    year = "1974",
    booktitle = "Proceedings of the Royal Society, London B, v. 187, p. 1-35",
    note = "talkorigins\_source = {true}; raw\_reference = {Mackie, G. O., Paul, D. H., Singla, C. M., Sleigh, M. A., and Williams, D. E., 1974, Branchial innervation and ciliary control in the ascidian Corella: Proceedings of the Royal Society, London B, v. 187, p. 1-35.}"
}

@misc{blight1976undulatory2,
    author = "Blight, A. R",
    title = "Undulatory swimming with and without waves of contraction",
    year = "1976",
    howpublished = "Nature, v. 264, p. 352-354",
    note = "talkorigins\_source = {true}; raw\_reference = {Blight, A. R., 1976, Undulatory swimming with and without waves of contraction: Nature, v. 264, p. 352-354.}"
}

@article{webb1976a24,
    author = "Webb, J. E",
    title = "A Review of Swimming in Amphioxus, in Spencer Davies, P., ed., Perspectives in Experimental Biology, 1 of Zoology, Proceedings of the Fiftieth Anniversary Meeting of the Society of Experimental Biology",
    year = "1976",
    journal = "Oxford, Pergamon, v. 1, p. 447-454",
    note = "talkorigins\_source = {true}; raw\_reference = {Webb, J. E., 1976, A Review of Swimming in Amphioxus, in Spencer Davies, P., ed., Perspectives in Experimental Biology, 1 of Zoology, Proceedings of the Fiftieth Anniversary Meeting of the Society of Experimental Biology: Oxford, Pergamon, v. 1, p. 447-454.}"
}

@article{blight1977the3,
    author = "Blight, A. R",
    title = "The muscular control of vertebrate swimming motions",
    year = "1977",
    journal = "Biological Reviews, v. 52, p. 181-218",
    note = "talkorigins\_source = {true}; raw\_reference = {Blight, A. R., 1977, The muscular control of vertebrate swimming motions: Biological Reviews, v. 52, p. 181-218.}"
}

@book{bone1978locomotor5,
    author = "Bone, Q",
    title = "Locomotor Muscle, in Hoar, W. S., and Randall, D. J., eds., Fish Physiology",
    year = "1978",
    publisher = "New York, Academic Press, v. VII",
    note = "talkorigins\_source = {true}; raw\_reference = {Bone, Q., 1978, Locomotor Muscle, in Hoar, W. S., and Randall, D. J., eds., Fish Physiology: New York, Academic Press, v. VII.}"
}

@article{taylor1979running21,
    author = "Taylor, C. R. et al",
    title = "Running in cheetahs, gazelles and goats",
    year = "1979",
    journal = "Energy cost and limb configuration: American Journal of Physiology, p. 848-850",
    note = "talkorigins\_source = {true}; raw\_reference = {Taylor, C. R. et al., 1979, Running in cheetahs, gazelles and goats: Energy cost and limb configuration: American Journal of Physiology, p. 848-850.}"
}

@misc{day1981vertebrate7,
    author = "Day, M. H",
    title = "Vertebrate Locomotion, 48 of Symposia of the Zoological Society of London",
    year = "1981",
    howpublished = "London, Zoological Society of London",
    note = "talkorigins\_source = {true}; raw\_reference = {Day, M. H., 1981, Vertebrate Locomotion, 48 of Symposia of the Zoological Society of London: London, Zoological Society of London.}"
}

@misc{thulborn1982speeds22,
    author = "Thulborn, R. A",
    title = "Speeds and gaits of dinosaurs",
    year = "1982",
    howpublished = "Palaeogeography, Palaeoclimatology, Palaeoecology, v. 38, p. 273-274",
    note = "talkorigins\_source = {true}; raw\_reference = {Thulborn, R. A., 1982, Speeds and gaits of dinosaurs: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 38, p. 273-274.}"
}

@misc{tarsitano1983stance20,
    author = "Tarsitano, S",
    title = "Stance and gait in theropod dinosaurs",
    year = "1983",
    howpublished = "Acta Palaeontologica Polonica, v. 28, p. 251-264",
    note = "talkorigins\_source = {true}; raw\_reference = {Tarsitano, S., 1983, Stance and gait in theropod dinosaurs: Acta Palaeontologica Polonica, v. 28, p. 251-264.}"
}

@article{bonaparte1984locomotion4,
    author = "Bonaparte, J. F",
    title = "Locomotion in rauisuchid thecodonts",
    year = "1984",
    journal = "Journal of Vertebrate Paleontology, v. 3, no. 4, p. 210-218",
    note = "talkorigins\_source = {true}; raw\_reference = {Bonaparte, J. F., 1984, Locomotion in rauisuchid thecodonts: Journal of Vertebrate Paleontology, v. 3, no. 4, p. 210-218.}"
}

It has long been pointed out by Gray that large aquatic animals, notably the dolphin, have been observed to achieve speeds which appear to be far beyond their muscular capabilities, unless they somehow experience laminar flow. Many workers have puzzled over this problem, and various possibilities have been propounded. In particular Wu has carried out a long theoretical analysis of the swimming of a slender fish in two dimensions, and he mentions the prospect of the zero momentum wake. The principle of the zero momentum wake (or boundary layer propulsion, as it is sometimes called) has often attracted the attention of aircraft propulsion engineers. A small wind tunnel experiment by Göbel and Oehler is of interest. They took a circular sieve, representing profile drag, and set this in relation to a propeller of the same diameter as the sieve. The sieve and the propeller were set side-by-side on a bar, and the power required to propel the model was measured. Then the sieve and the propeller were set in tandem, with the sieve in front of the propeller, and the power required measured again. The power required for the tandem arrangement was found to be significantly less than that required for the side-by-side arrangement.

@article{doi101017s0001924000020704,
    author = "Elliott, Julia",
    title = "A note on the propulsive systems of fishes and birds, with possible application to manpowered flight",
    year = "1984",
    journal = "The Aeronautical Journal",
    abstract = "It has long been pointed out by Gray that large aquatic animals, notably the dolphin, have been observed to achieve speeds which appear to be far beyond their muscular capabilities, unless they somehow experience laminar flow. Many workers have puzzled over this problem, and various possibilities have been propounded. In particular Wu has carried out a long theoretical analysis of the swimming of a slender fish in two dimensions, and he mentions the prospect of the zero momentum wake. The principle of the zero momentum wake (or boundary layer propulsion, as it is sometimes called) has often attracted the attention of aircraft propulsion engineers. A small wind tunnel experiment by Göbel and Oehler is of interest. They took a circular sieve, representing profile drag, and set this in relation to a propeller of the same diameter as the sieve. The sieve and the propeller were set side-by-side on a bar, and the power required to propel the model was measured. Then the sieve and the propeller were set in tandem, with the sieve in front of the propeller, and the power required measured again. The power required for the tandem arrangement was found to be significantly less than that required for the side-by-side arrangement.",
    url = "https://doi.org/10.1017/s0001924000020704",
    doi = "10.1017/s0001924000020704",
    openalex = "W2490020007",
    references = "doi101017s0022112061000949, doi101017s0022112071000570, doi101017s0368393100107680"
}

A comparison has been made of the patterns of muscle activity during swimming in the intact and spinal lamprey, and the patterns of ventral root activity in the in vitro preparation of the lamprey spinal cord. Electromyographic (e.m.g.) activity was recorded with intramuscular bipolar electrodes from three segmental levels in intact lampreys swimming in a swim-mill at a range of swimming speeds. The patterns of activity obtained were similar to those seen in elasmobranch and teleost fish. After high spinal transection, lampreys could be induced to swim continuously for a period of several minutes in the swim-mill by a light initial mechanical stimulation of the tail or dorsal fin. The patterns of e.m.g. activity obtained from spinal animals at a range of swimming speeds were similar to those obtained in the intact state. Portions of spinal cord were isolated encompassing those segments from which e.m.g. recordings had been made and ventral root recordings were made in vitro of the rhythmic activity induced by bath application of D-glutamate. In all experiments the mean duration of the bursts of activity at any segmental level was directly proportional to the mean cycle duration, and the constant of proportionality (about 0.36) was similar for all three types of preparation. In all preparations the mean time delay for the activation of segments in the rostral-caudal direction was proportional to the cycle duration and to the number of segments between recording positions. The proportionality constant, or phase lag per segment, was approximately equal to 0.01 in all three types of preparation.

@article{doi101113jphysiol1984sp015063,
    author = "Wallén, P. and Williams, Thelma L.",
    title = "Fictive locomotion in the lamprey spinal cord in vitro compared with swimming in the intact and spinal animal.",
    year = "1984",
    journal = "The Journal of Physiology",
    abstract = "A comparison has been made of the patterns of muscle activity during swimming in the intact and spinal lamprey, and the patterns of ventral root activity in the in vitro preparation of the lamprey spinal cord. Electromyographic (e.m.g.) activity was recorded with intramuscular bipolar electrodes from three segmental levels in intact lampreys swimming in a swim-mill at a range of swimming speeds. The patterns of activity obtained were similar to those seen in elasmobranch and teleost fish. After high spinal transection, lampreys could be induced to swim continuously for a period of several minutes in the swim-mill by a light initial mechanical stimulation of the tail or dorsal fin. The patterns of e.m.g. activity obtained from spinal animals at a range of swimming speeds were similar to those obtained in the intact state. Portions of spinal cord were isolated encompassing those segments from which e.m.g. recordings had been made and ventral root recordings were made in vitro of the rhythmic activity induced by bath application of D-glutamate. In all experiments the mean duration of the bursts of activity at any segmental level was directly proportional to the mean cycle duration, and the constant of proportionality (about 0.36) was similar for all three types of preparation. In all preparations the mean time delay for the activation of segments in the rostral-caudal direction was proportional to the cycle duration and to the number of segments between recording positions. The proportionality constant, or phase lag per segment, was approximately equal to 0.01 in all three types of preparation.",
    url = "https://doi.org/10.1113/jphysiol.1984.sp015063",
    doi = "10.1113/jphysiol.1984.sp015063",
    openalex = "W2095427020"
}

@book{macmahon1984muscles16,
    author = "MacMahon, T. A",
    title = "Muscles, Reflexes and Locomotion",
    year = "1984",
    publisher = "Princeton, Princeton University Press",
    note = "talkorigins\_source = {true}; raw\_reference = {MacMahon, T. A., 1984, Muscles, Reflexes and Locomotion: Princeton, Princeton University Press.}"
}

@article{alexander1986animal,
    author = "Alexander, R. McNeill",
    title = "Animal locomotion: Three kinds of flying in animals",
    year = "1986",
    journal = "Nature",
    url = "https://doi.org/10.1038/321113a0",
    doi = "10.1038/321113a0",
    number = "6066",
    openalex = "W2038551887",
    pages = "113-114",
    volume = "321"
}

@misc{parrish1986locomotor19,
    author = "Parrish, J. M",
    title = "Locomotor adaptations in the hindlimb and pelvis of the Thecodontia",
    year = "1986",
    howpublished = "Hunteria, v. 1, p. 2-35",
    note = "talkorigins\_source = {true}; raw\_reference = {Parrish, J. M., 1986, Locomotor adaptations in the hindlimb and pelvis of the Thecodontia: Hunteria, v. 1, p. 2-35.}"
}

@misc{carrier1987the6,
    author = "Carrier, D. R",
    title = "The evolution of locomotion stamina in tetrapods",
    year = "1987",
    howpublished = "Circumventing a mechanical constraint: Paleobiology, v. 13, p. 326-341",
    note = "talkorigins\_source = {true}; raw\_reference = {Carrier, D. R., 1987, The evolution of locomotion stamina in tetrapods: Circumventing a mechanical constraint: Paleobiology, v. 13, p. 326-341.}"
}

Summary The objective of this paper is a description of animal swimming and flying locomotion in terms of wave theory. In this context various oscillatory organs of locomotion, such as flagella, fins and wings, are interpreted as waveguides capable of transmitting mechanical transverse waves. Furthermore, the Poynting concept is used, according to which every type of wave transports not only energy but also momentum. Even with no detailed knowledge of the hydro- and aerodynamic flow fields it is possible to calculate the wave power, the propulsive force, and the propulsive efficiency with the means and methods of vibrational theory alone.

@article{bschorr1988propulsive,
    author = "Bschorr, O.",
    title = "Propulsive mechanisms in animal swimming and flying locomotion",
    year = "1988",
    journal = "The Aeronautical Journal",
    abstract = "Summary The objective of this paper is a description of animal swimming and flying locomotion in terms of wave theory. In this context various oscillatory organs of locomotion, such as flagella, fins and wings, are interpreted as waveguides capable of transmitting mechanical transverse waves. Furthermore, the Poynting concept is used, according to which every type of wave transports not only energy but also momentum. Even with no detailed knowledge of the hydro- and aerodynamic flow fields it is possible to calculate the wave power, the propulsive force, and the propulsive efficiency with the means and methods of vibrational theory alone.",
    url = "https://doi.org/10.1017/s0001924000021928",
    doi = "10.1017/s0001924000021928",
    number = "912",
    openalex = "W2486523576",
    pages = "84-90",
    volume = "92",
    references = "doi101007bf02040967, doi1010160094576580900454, doi101017s0001924000020704, openalexw145863232, openalexw2971991135"
}

This chapter explores the ways fish swim from zero speeds in station-holding and hovering, through cruising and sprint, to fast starts. The range of power required to swim over such a range is formidable. Effective swimming is achieved by performance range fractionation using gaits. Gaits are defined by the use of various combinations of propulsor type (median and paired fin or body/caudal fin propulsors), propulsor kinematics (station-holding, hovering, steady swimming and fast starts, muscle (red, pink and white), and locomotor behaviour (continuous and burst-and-coast swimming). The number of gaits expressed within lineages, and presumably locomotor performance range, has generally increased over evolutionary time. At any given evolutionary level, radiations have been common, often enhancing certain gaits but reducing performance in others (gait suppression). The range of gaits expressed during ontogeny also increases. Environmental influences tend to reduce metabolic scope so that successive gaits tend to be recruited at lower speeds (gait compression). Directions for future research include use of computational models better to model pressure distributions and forces during swimming. Problems especially of manoeuvrability, agility and stability have been neglected by traditional interest in maximum speed and acceleration.

@incollection{doi101017cbo9780511983641005,
    author = "Webb, Paul W.",
    title = "The biology of fish swimming",
    year = "1994",
    booktitle = "Cambridge University Press eBooks",
    abstract = "This chapter explores the ways fish swim from zero speeds in station-holding and hovering, through cruising and sprint, to fast starts. The range of power required to swim over such a range is formidable. Effective swimming is achieved by performance range fractionation using gaits. Gaits are defined by the use of various combinations of propulsor type (median and paired fin or body/caudal fin propulsors), propulsor kinematics (station-holding, hovering, steady swimming and fast starts, muscle (red, pink and white), and locomotor behaviour (continuous and burst-and-coast swimming). The number of gaits expressed within lineages, and presumably locomotor performance range, has generally increased over evolutionary time. At any given evolutionary level, radiations have been common, often enhancing certain gaits but reducing performance in others (gait suppression). The range of gaits expressed during ontogeny also increases. Environmental influences tend to reduce metabolic scope so that successive gaits tend to be recruited at lower speeds (gait compression). Directions for future research include use of computational models better to model pressure distributions and forces during swimming. Problems especially of manoeuvrability, agility and stability have been neglected by traditional interest in maximum speed and acceleration.",
    url = "https://doi.org/10.1017/cbo9780511983641.005",
    doi = "10.1017/cbo9780511983641.005",
    openalex = "W984092848"
}

Labriform, or pectoral fin, propulsion is the primary swimming mode for many fishes, even at high relative speeds. Although kinematic data are critical for evaluating hydrodynamic models of propulsion, these data are largely lacking for labriform swimmers, especially for species that employ an exclusively labriform mode across a broad range of speeds. We present data on pectoral fin locomotion in Gomphosus varius (Labridae), a tropical coral reef fish that uses a lift-based mechanism to fly under water at sustained speeds of 1­6 total body lengths s-1 (TL s-1). Lateral- and dorsal-view video images of three fish swimming in a flow tank at 1­4 TL s-1 were recorded at 60 Hz. From the two views, we reconstructed the three-dimensional motion of the center of mass, the fin tip and two fin chords for multiple fin beats of each fish at each of four speeds. In G. varius, the fin oscillates largely up and down: the stroke plane is tilted by approximately 20 ° from the vertical. Both frequency and the area swept by the pectoral fins increase with swimming speed. Interestingly, there are individual differences in how this area increases. Relative to the fish, the fin tip in lateral view moves along the path of a thin, inclined figure-of-eight. Relative to a stationary observer, the fin tip traces a sawtooth pattern, but the teeth are recumbent (indicating net backwards movement) only at the slowest speeds. Distal fin chords pitch nose downward during the downstroke and nose upward during the upstroke. Hydrodynamic angles of attack are largely positive during the downstroke and negative during the upstroke. The geometry of the fin and incident flow suggests that the fin is generating lift with large upward and small forward components during the downstroke. The negative incident angles during the upstroke suggest that the fin is generating largely thrust during the upstroke. In general, the large thrust is combined with a downward force during the upstroke, but the net backwards motion of the fin at slow speeds generates a small upward component during slow swimming. Both the alternating sign of the hydrodynamic angle of attack and the observed reduced frequencies suggest that unsteady effects are important in G. varius aquatic flight, especially at low speeds. This study provides a framework for the comparison of aquatic flight by fishes with aerial flight by birds, bats and insects.

@article{doi101242jeb200111549,
    author = "Walker, Jeffrey A. and Westneat, Mark W.",
    title = "Labriform Propulsion in Fishes: Kinematics of Flapping Aquatic Flight in the Bird Wrasse Gomphosus Varius (Labridae)",
    year = "1997",
    journal = "Journal of Experimental Biology",
    abstract = "Labriform, or pectoral fin, propulsion is the primary swimming mode for many fishes, even at high relative speeds. Although kinematic data are critical for evaluating hydrodynamic models of propulsion, these data are largely lacking for labriform swimmers, especially for species that employ an exclusively labriform mode across a broad range of speeds. We present data on pectoral fin locomotion in Gomphosus varius (Labridae), a tropical coral reef fish that uses a lift-based mechanism to fly under water at sustained speeds of 1­6 total body lengths s-1 (TL s-1). Lateral- and dorsal-view video images of three fish swimming in a flow tank at 1­4 TL s-1 were recorded at 60 Hz. From the two views, we reconstructed the three-dimensional motion of the center of mass, the fin tip and two fin chords for multiple fin beats of each fish at each of four speeds. In G. varius, the fin oscillates largely up and down: the stroke plane is tilted by approximately 20 ° from the vertical. Both frequency and the area swept by the pectoral fins increase with swimming speed. Interestingly, there are individual differences in how this area increases. Relative to the fish, the fin tip in lateral view moves along the path of a thin, inclined figure-of-eight. Relative to a stationary observer, the fin tip traces a sawtooth pattern, but the teeth are recumbent (indicating net backwards movement) only at the slowest speeds. Distal fin chords pitch nose downward during the downstroke and nose upward during the upstroke. Hydrodynamic angles of attack are largely positive during the downstroke and negative during the upstroke. The geometry of the fin and incident flow suggests that the fin is generating lift with large upward and small forward components during the downstroke. The negative incident angles during the upstroke suggest that the fin is generating largely thrust during the upstroke. In general, the large thrust is combined with a downward force during the upstroke, but the net backwards motion of the fin at slow speeds generates a small upward component during slow swimming. Both the alternating sign of the hydrodynamic angle of attack and the observed reduced frequencies suggest that unsteady effects are important in G. varius aquatic flight, especially at low speeds. This study provides a framework for the comparison of aquatic flight by fishes with aerial flight by birds, bats and insects.",
    url = "https://doi.org/10.1242/jeb.200.11.1549",
    doi = "10.1242/jeb.200.11.1549",
    openalex = "W2169337581",
    references = "doi101242jeb1301275"
}

Several physico-mechanical designs evolved in fish are currently inspiring robotic devices for propulsion and maneuvering purposes in underwater vehicles. Considering the potential benefits involved, this paper presents an overview of the swimming mechanisms employed by fish. The motivation is to provide a relevant and useful introduction to the existing literature for engineers with an interest in the emerging area of aquatic biomechanisms. The fish swimming types are presented, following the well-established classification scheme and nomenclature originally proposed by Breder. Fish swim either by body and/or caudal fin (BCF) movements or using median and/or paired fin (MPF) propulsion. The latter is generally employed at slow speeds, offering greater maneuverability and better propulsive efficiency, while BCF movements can achieve greater thrust and accelerations. For both BCF and MPF locomotion, specific swimming modes are identified, based on the propulsor and the type of movements (oscillatory or undulatory) employed for thrust generation. Along with general descriptions and kinematic data, the analytical approaches developed to study each swimming mode are also introduced. Particular reference is made to lunate tail propulsion, undulating fins, and labriform (oscillatory pectoral fin) swimming mechanisms, identified as having the greatest potential for exploitation in artificial systems.

@article{doi10110948757275,
    author = "Sfakiotakis, Michael and Lane, David M. and Davies, J.B.C.",
    title = "Review of fish swimming modes for aquatic locomotion",
    year = "1999",
    journal = "IEEE Journal of Oceanic Engineering",
    abstract = "Several physico-mechanical designs evolved in fish are currently inspiring robotic devices for propulsion and maneuvering purposes in underwater vehicles. Considering the potential benefits involved, this paper presents an overview of the swimming mechanisms employed by fish. The motivation is to provide a relevant and useful introduction to the existing literature for engineers with an interest in the emerging area of aquatic biomechanisms. The fish swimming types are presented, following the well-established classification scheme and nomenclature originally proposed by Breder. Fish swim either by body and/or caudal fin (BCF) movements or using median and/or paired fin (MPF) propulsion. The latter is generally employed at slow speeds, offering greater maneuverability and better propulsive efficiency, while BCF movements can achieve greater thrust and accelerations. For both BCF and MPF locomotion, specific swimming modes are identified, based on the propulsor and the type of movements (oscillatory or undulatory) employed for thrust generation. Along with general descriptions and kinematic data, the analytical approaches developed to study each swimming mode are also introduced. Particular reference is made to lunate tail propulsion, undulating fins, and labriform (oscillatory pectoral fin) swimming mechanisms, identified as having the greatest potential for exploitation in artificial systems.",
    url = "https://doi.org/10.1109/48.757275",
    doi = "10.1109/48.757275",
    openalex = "W2117289015",
    references = "doi101017s0022112070001830, openalexw1575479768"
}

Fish swimming has often been simplified into the motions of a two-dimensional slice through the horizontal midline, as though fishes live in a flat world devoid of a third dimension. While fish bodies do undulate primarily horizontally, this motion has important three-dimensional components, and fish fins can move in a complex three-dimensional manner. Recent results suggest that an understanding of the three-dimensional body shape and fin motions is vital for explaining the mechanics of swimming, and that two-dimensional representations of fish locomotion are misleading. In this study, we first examine axial swimming from the two-dimensional viewpoint, detailing the limitations of this view. Then we present data on the kinematics and hydrodynamics of the dorsal fin, the anal fin and the caudal fin during steady swimming and maneuvering in brook trout, Salvelinus fontinalis, bluegill sunfish, Lepomis macrochirus, and yellow perch, Perca flavescens. These fishes actively move the dorsal and anal fins during swimming, resulting in curvature along both anterio-posterior and dorso-ventral axes. The momentum imparted to the fluid by these fins comprises a substantial portion of total swimming force, adding to thrust and contributing to roll stability. While swimming, the caudal fin also actively curves dorso-ventrally, producing vortices separately from both its upper and lower lobes. This functional separation of the lobes may allow additional control of three-dimensional orientation, but probably reduces swimming efficiency. In contrast, fish may boost the caudal fin's efficiency by taking advantage of the flow from the dorsal and anal fins as it interacts with the flow around the caudal fin itself. During maneuvering, fish readily use their fins outside of the normal planes of motion. For example, the dorsal fin can flick laterally, orienting its surface perpendicular to the body, to help in turning and braking. These data demonstrate that, while fish do move primarily in the horizontal plane, neither their bodies nor their motions can accurately be simplified in a two-dimensional representation. To begin to appreciate the functional consequences of the diversity of fish body shapes and locomotor strategies, one must escape Flatland to examine all three dimensions.

@article{doi101242jeb008128,
    author = "Tytell, Eric and Standen, Emily M. and Lauder, George",
    title = "Escaping Flatland: three-dimensional kinematics and hydrodynamics of median fins in fishes",
    year = "2007",
    journal = "Journal of Experimental Biology",
    abstract = "Fish swimming has often been simplified into the motions of a two-dimensional slice through the horizontal midline, as though fishes live in a flat world devoid of a third dimension. While fish bodies do undulate primarily horizontally, this motion has important three-dimensional components, and fish fins can move in a complex three-dimensional manner. Recent results suggest that an understanding of the three-dimensional body shape and fin motions is vital for explaining the mechanics of swimming, and that two-dimensional representations of fish locomotion are misleading. In this study, we first examine axial swimming from the two-dimensional viewpoint, detailing the limitations of this view. Then we present data on the kinematics and hydrodynamics of the dorsal fin, the anal fin and the caudal fin during steady swimming and maneuvering in brook trout, Salvelinus fontinalis, bluegill sunfish, Lepomis macrochirus, and yellow perch, Perca flavescens. These fishes actively move the dorsal and anal fins during swimming, resulting in curvature along both anterio-posterior and dorso-ventral axes. The momentum imparted to the fluid by these fins comprises a substantial portion of total swimming force, adding to thrust and contributing to roll stability. While swimming, the caudal fin also actively curves dorso-ventrally, producing vortices separately from both its upper and lower lobes. This functional separation of the lobes may allow additional control of three-dimensional orientation, but probably reduces swimming efficiency. In contrast, fish may boost the caudal fin's efficiency by taking advantage of the flow from the dorsal and anal fins as it interacts with the flow around the caudal fin itself. During maneuvering, fish readily use their fins outside of the normal planes of motion. For example, the dorsal fin can flick laterally, orienting its surface perpendicular to the body, to help in turning and braking. These data demonstrate that, while fish do move primarily in the horizontal plane, neither their bodies nor their motions can accurately be simplified in a two-dimensional representation. To begin to appreciate the functional consequences of the diversity of fish body shapes and locomotor strategies, one must escape Flatland to examine all three dimensions.",
    url = "https://doi.org/10.1242/jeb.008128",
    doi = "10.1242/jeb.008128",
    openalex = "W2115789364"
}

Burst-and-coast swimming performance in fish-like locomotion is studied via two-dimensional numerical simulation. The numerical method used is the collocated finite-volume adaptive Cartesian cut-cell method developed previously. The NACA00xx airfoil shape is used as an equilibrium fish-body form. Swimming in a burst-and-coast style is computed assuming that the burst phase is composed of a single tail-beat. Swimming efficiency is evaluated in terms of the mass-specific cost of transport instead of the Froude efficiency. The effects of the Reynolds number (based on the body length and burst time), duty cycle and fineness ratio (the body length over the largest thickness) on swimming performance (momentum capacity and the mass-specific cost of transport) are studied quantitatively. The results lead to a conclusion consistent with previous findings that a larval fish seldom swims in a burst-and-coast style. Given mass and swimming speed, a fish needs the least cost if it swims in a burst-and-coast style with a fineness ratio of 8.33. This energetically optimal fineness ratio is larger than that derived from the simple hydromechanical model proposed in literature. The calculated amount of energy saving in burst-and-coast swimming is comparable with the real-fish estimation in the literature. Finally, the predicted wake-vortex structures of both continuous and burst-and-coast swimming are biologically relevant.

@article{doi1010881748318243036001,
    author = "Chung, M.M.",
    title = "On burst-and-coast swimming performance in fish-like locomotion",
    year = "2009",
    journal = "Bioinspiration \& Biomimetics",
    abstract = "Burst-and-coast swimming performance in fish-like locomotion is studied via two-dimensional numerical simulation. The numerical method used is the collocated finite-volume adaptive Cartesian cut-cell method developed previously. The NACA00xx airfoil shape is used as an equilibrium fish-body form. Swimming in a burst-and-coast style is computed assuming that the burst phase is composed of a single tail-beat. Swimming efficiency is evaluated in terms of the mass-specific cost of transport instead of the Froude efficiency. The effects of the Reynolds number (based on the body length and burst time), duty cycle and fineness ratio (the body length over the largest thickness) on swimming performance (momentum capacity and the mass-specific cost of transport) are studied quantitatively. The results lead to a conclusion consistent with previous findings that a larval fish seldom swims in a burst-and-coast style. Given mass and swimming speed, a fish needs the least cost if it swims in a burst-and-coast style with a fineness ratio of 8.33. This energetically optimal fineness ratio is larger than that derived from the simple hydromechanical model proposed in literature. The calculated amount of energy saving in burst-and-coast swimming is comparable with the real-fish estimation in the literature. Finally, the predicted wake-vortex structures of both continuous and burst-and-coast swimming are biologically relevant.",
    url = "https://doi.org/10.1088/1748-3182/4/3/036001",
    doi = "10.1088/1748-3182/4/3/036001",
    openalex = "W2039103601"
}

BACKGROUND: Planktonic ciliated larvae are characteristic for the life cycle of marine invertebrates. Their most prominent feature is the apical organ harboring sensory cells and neurons of largely undetermined function. An elucidation of the relationships between various forms of primary larvae and apical organs is key to understanding the evolution of animal life cycles. These relationships have remained enigmatic due to the scarcity of comparative molecular data. RESULTS: To compare apical organs and larval body patterning, we have studied regionalization of the episphere, the upper hemisphere of the trochophore larva of the marine annelid Platynereis dumerilii. We examined the spatial distribution of transcription factors and of Wnt signaling components previously implicated in anterior neural development. Pharmacological activation of Wnt signaling with Gsk3β antagonists abolishes expression of apical markers, consistent with a repressive role of Wnt signaling in the specification of apical tissue. We refer to this Wnt-sensitive, six3- and foxq2-expressing part of the episphere as the 'apical plate'. We also unraveled a molecular signature of the apical organ--devoid of six3 but expressing foxj, irx, nkx3 and hox--that is shared with other marine phyla including cnidarians. Finally, we characterized the cell types that form part of the apical organ by profiling by image registration, which allows parallel expression profiling of multiple cells. Besides the hox-expressing apical tuft cells, this revealed the presence of putative light- and mechanosensory as well as multiple peptidergic cell types that we compared to apical organ cell types of other animal phyla. CONCLUSIONS: The similar formation of a six3+, foxq2+ apical plate, sensitive to Wnt activity and with an apical tuft in its six3-free center, is most parsimoniously explained by evolutionary conservation. We propose that a simple apical organ--comprising an apical tuft and a basal plexus innervated by sensory-neurosecretory apical plate cells--was present in the last common ancestors of cnidarians and bilaterians. One of its ancient functions would have been the control of metamorphosis. Various types of apical plate cells would then have subsequently been added to the apical organ in the divergent bilaterian lineages. Our findings support an ancient and common origin of primary ciliated larvae.

@article{doi10118617417007127,
    author = "Marlow, Heather and Tosches, Maria Antonietta and Tomer, Raju and Steinmetz, Patrick R. H. and Lauri, Antonella and Larsson, Tomas and Arendt, Detlev",
    title = "Larval body patterning and apical organs are conserved in animal evolution",
    year = "2014",
    journal = "BMC Biology",
    abstract = "BACKGROUND: Planktonic ciliated larvae are characteristic for the life cycle of marine invertebrates. Their most prominent feature is the apical organ harboring sensory cells and neurons of largely undetermined function. An elucidation of the relationships between various forms of primary larvae and apical organs is key to understanding the evolution of animal life cycles. These relationships have remained enigmatic due to the scarcity of comparative molecular data. RESULTS: To compare apical organs and larval body patterning, we have studied regionalization of the episphere, the upper hemisphere of the trochophore larva of the marine annelid Platynereis dumerilii. We examined the spatial distribution of transcription factors and of Wnt signaling components previously implicated in anterior neural development. Pharmacological activation of Wnt signaling with Gsk3β antagonists abolishes expression of apical markers, consistent with a repressive role of Wnt signaling in the specification of apical tissue. We refer to this Wnt-sensitive, six3- and foxq2-expressing part of the episphere as the 'apical plate'. We also unraveled a molecular signature of the apical organ--devoid of six3 but expressing foxj, irx, nkx3 and hox--that is shared with other marine phyla including cnidarians. Finally, we characterized the cell types that form part of the apical organ by profiling by image registration, which allows parallel expression profiling of multiple cells. Besides the hox-expressing apical tuft cells, this revealed the presence of putative light- and mechanosensory as well as multiple peptidergic cell types that we compared to apical organ cell types of other animal phyla. CONCLUSIONS: The similar formation of a six3+, foxq2+ apical plate, sensitive to Wnt activity and with an apical tuft in its six3-free center, is most parsimoniously explained by evolutionary conservation. We propose that a simple apical organ--comprising an apical tuft and a basal plexus innervated by sensory-neurosecretory apical plate cells--was present in the last common ancestors of cnidarians and bilaterians. One of its ancient functions would have been the control of metamorphosis. Various types of apical plate cells would then have subsequently been added to the apical organ in the divergent bilaterian lineages. Our findings support an ancient and common origin of primary ciliated larvae.",
    url = "https://doi.org/10.1186/1741-7007-12-7",
    doi = "10.1186/1741-7007-12-7",
    openalex = "W2039015384",
    references = "doi101016jcell200702040, doi101016s0092867403004690, doi101038nature03158, doi101038ng263, doi101093bioinformaticsbti263, doi101093molbevmsr121, doi101093nargkh340, doi101093oxfordjournalsmolbeva026334, doi101093sysbiosyq010, doi105860choice501469"
}

Numerical simulations are used to investigate the hydrodynamic benefits of body–fin and fin–fin interactions in a fish model in carangiform swimming. The geometry and kinematics of the model are reconstructed in three-dimensions from high-speed videos of a live fish, Crevalle Jack (Caranx hippos), during steady swimming. The simulations employ an immersed-boundary-method-based incompressible Navier–Stokes flow solver that allows us to quantitatively characterize the propulsive performance of the fish median fins (the dorsal and the anal fins) and the caudal fin using three-dimensional full body simulations. This includes a detailed analysis of associated performance enhancement mechanisms and their connection to the vortex dynamics. Comparisons are made using three different models containing different combinations of the fish body and fins to provide insights into the force production. The results indicate that the fish produces high performance propulsion by utilizing complex interactions among the fins and the body. By connecting the vortex dynamics and surface force distribution, it is found that the leading-edge vortices produced by the caudal fin are associated with most of the thrust production in this fish model. These vortices could be strengthened by the vorticity capture from the vortices generated by the posterior body during undulatory motion. Meanwhile, the pressure difference between the two sides of posterior body resulting from the posterior body vortices (PBVs) helps with the alleviation of the body drag. The appearance of the median fins in the posterior region further strengthens the PBVs and caudal-fin wake capture mechanism. This work provides new physical insights into how body–fin and fin–fin interactions enhance thrust production in swimming fishes, and emphasizes that movements of both the body and fins contribute to overall swimming performance in fish locomotion.

@article{doi101017jfm2017533,
    author = "Liu, Geng and Ren, Yan and Dong, Haibo and Akanyeti, Otar and Liao, James C. and Lauder, George",
    title = "Computational analysis of vortex dynamics and performance enhancement due to body–fin and fin–fin interactions in fish-like locomotion",
    year = "2017",
    journal = "Journal of Fluid Mechanics",
    abstract = "Numerical simulations are used to investigate the hydrodynamic benefits of body–fin and fin–fin interactions in a fish model in carangiform swimming. The geometry and kinematics of the model are reconstructed in three-dimensions from high-speed videos of a live fish, Crevalle Jack (Caranx hippos), during steady swimming. The simulations employ an immersed-boundary-method-based incompressible Navier–Stokes flow solver that allows us to quantitatively characterize the propulsive performance of the fish median fins (the dorsal and the anal fins) and the caudal fin using three-dimensional full body simulations. This includes a detailed analysis of associated performance enhancement mechanisms and their connection to the vortex dynamics. Comparisons are made using three different models containing different combinations of the fish body and fins to provide insights into the force production. The results indicate that the fish produces high performance propulsion by utilizing complex interactions among the fins and the body. By connecting the vortex dynamics and surface force distribution, it is found that the leading-edge vortices produced by the caudal fin are associated with most of the thrust production in this fish model. These vortices could be strengthened by the vorticity capture from the vortices generated by the posterior body during undulatory motion. Meanwhile, the pressure difference between the two sides of posterior body resulting from the posterior body vortices (PBVs) helps with the alleviation of the body drag. The appearance of the median fins in the posterior region further strengthens the PBVs and caudal-fin wake capture mechanism. This work provides new physical insights into how body–fin and fin–fin interactions enhance thrust production in swimming fishes, and emphasizes that movements of both the body and fins contribute to overall swimming performance in fish locomotion.",
    url = "https://doi.org/10.1017/jfm.2017.533",
    doi = "10.1017/jfm.2017.533",
    openalex = "W2754658223"
}

@inproceedings{han2020effects,
    author = "Han, Pan and Wang, Junshi and Dong, Haibo",
    title = "Effects of Intermittent Swimming Gait in Fish-Like Locomotion",
    year = "2020",
    booktitle = "AIAA Scitech 2020 Forum",
    url = "https://doi.org/10.2514/6.2020-1779",
    doi = "10.2514/6.2020-1779",
    openalex = "W2998233015",
    references = "doi101007s1040901706943, doi101016030096299190382m, doi101016jjcp201904062, doi101017cbo9780511983641005, doi101017jfm2017533, doi1010881748318243036001, doi101098rspb19710085, doi10110948757275, doi101242jeb008128, openalexw2744262668"
}

Jellyfish (Medusozoa) have been deemed the most energy-efficient animals in the world. Their bell morphology and relatively simple nervous systems make them attractive to robotocists. Although, the science community has devoted much attention to understanding their swimming performance, there is still much to be learned about the jet propulsive locomotive gait displayed by prolate jellyfish. Traditionally, computational scientists have assumed uniform duty cycle kinematics when computationally modeling jellyfish locomotion. In this study we used fluid-structure interaction modeling to determine possible enhancements in performance from shuffling different duty cycles together across multiple Reynolds numbers and contraction frequencies. Increases in speed and reductions in cost of transport were observed as high as 80% and 50%, respectively. Generally, the net effects were greater for cases involving lower contraction frequencies. Overall, robust duty cycle combinations were determined that led to enhanced or impeded performance.

@article{doi10108817483190ac2afe,
    author = "Baldwin, Tierney and Battista, Nicholas",
    title = "Hopscotching Jellyfish: combining different duty cycle kinematics can lead to enhanced swimming performance",
    year = "2021",
    journal = "arXiv (Cornell University)",
    abstract = "Jellyfish (Medusozoa) have been deemed the most energy-efficient animals in the world. Their bell morphology and relatively simple nervous systems make them attractive to robotocists. Although, the science community has devoted much attention to understanding their swimming performance, there is still much to be learned about the jet propulsive locomotive gait displayed by prolate jellyfish. Traditionally, computational scientists have assumed uniform duty cycle kinematics when computationally modeling jellyfish locomotion. In this study we used fluid-structure interaction modeling to determine possible enhancements in performance from shuffling different duty cycles together across multiple Reynolds numbers and contraction frequencies. Increases in speed and reductions in cost of transport were observed as high as 80\% and 50\%, respectively. Generally, the net effects were greater for cases involving lower contraction frequencies. Overall, robust duty cycle combinations were determined that led to enhanced or impeded performance.",
    url = "https://doi.org/10.1088/1748-3190/ac2afe",
    doi = "10.1088/1748-3190/ac2afe",
    openalex = "W3204959302",
    references = "han2020effects"
}

@incollection{beauregardNonefast,
    author = "Beauregard, Matthew and Kennedy, Paul J. and Debenham, John",
    title = "Fast simulation of animal locomotion: lamprey swimming",
    year = "None",
    booktitle = "IFIP International Federation for Information Processing",
    url = "https://doi.org/10.1007/978-0-387-34749-3\_26",
    doi = "10.1007/978-0-387-34749-3\_26",
    openalex = "W1578747078",
    pages = "247-256",
    references = "doi101007bf00199436, doi101007bf01185408, openalexw1896888274, openalexw2009223819, openalexw2559399192"
}