scholarly journals Autonomous changes in the swimming direction of sperm in the gastropod Strombus luhuanus

2013 ◽  
Vol 217 (6) ◽  
pp. 986-996 ◽  
Author(s):  
K. Shiba ◽  
D. Shibata ◽  
K. Inaba
Keyword(s):  
Swimming Direction ◽  
Strombus Luhuanus

scholarly journals Transition in swimming direction in a model self-propelled inertial swimmer

2019 ◽  
Vol 4 (2) ◽  
Author(s):  
Thomas Dombrowski ◽  
Shannon K. Jones ◽  
Georgios Katsikis ◽  
Amneet Pal Singh Bhalla ◽  
Boyce E. Griffith ◽  
...  
Keyword(s):  
Swimming Direction

scholarly journals Feeding strategy of mackerel in the Norwegian Sea relative to currents, temperature, and prey

2015 ◽  
Vol 73 (4) ◽  
pp. 1127-1137 ◽  
Author(s):  
Leif Nøttestad ◽  
Justine Diaz ◽  
Hector Penã ◽  
Henrik Søiland ◽  
Geir Huse ◽  
...  
Keyword(s):  
Swimming Speed ◽  
Swimming Performance ◽  
Feeding Strategy ◽  
Near Field ◽  
Norwegian Sea ◽  
Swimming Direction ◽  
Atlantic Mackerel ◽  
The North ◽  
Foraging Rate ◽  
Feeding Resources

Abstract High abundance of Northeast Atlantic mackerel (Scomber scombrus L.), combined with limited food resources, may now force mackerel to enter new and productive regions in the northern Norwegian Sea. However, it is not known how mackerel exploit the spatially varying feeding resources, and their vertical distribution and swimming behaviour are also largely unknown. During an ecosystem survey in the Norwegian Sea during the summer feeding season, swimming direction, and speed of mackerel schools were recorded with high-frequency omnidirectional sonar in four different regions relative to currents, ambient temperature, and zooplankton. A total of 251 schools were tracked, and fish and zooplankton were sampled with pelagic trawl and WP-2 plankton net. Except for the southwest region, swimming direction of the tracked schools coincided with the prevailing northerly Atlantic current direction in the Norwegian Sea. Swimming with the current saves energy, and the current also provides a directional cue towards the most productive areas in the northern Norwegian Sea. Average mean swimming speed in all regions combined was ∼3.8 body lengths s−1. However, fish did not swim in a straight course, but often changed direction, suggesting active feeding in the near field. Fish were largest and swimming speed lowest in the northwest region which had the highest plankton concentrations and lowest temperature. Mackerel swam close to the surface at a depth of 8–39 m, with all schools staying above the thermocline in waters of at least 6°C. In surface waters, mackerel encounter improved foraging rate and swimming performance. Going with the flow until temperature is too low, based on an expectation of increasing foraging rate towards the north while utilizing available prey under way, could be a simple and robust feeding strategy for mackerel in the Norwegian Sea.

Classes of Light-Evoked Response in the Retina of Strombus

1979 ◽  
Vol 80 (1) ◽  
pp. 287-297
Author(s):  
FREDERICK N. QUANDT ◽  
HOWARD L. GILLARY
Keyword(s):  
Optic Nerve ◽  
Action Potentials ◽  
Input Resistance ◽  
Resting Potential ◽  
Recording Site ◽  
Charging Time ◽  
Rate Of Decay ◽  
Hyperpolarizing Response ◽  
Strombus Luhuanus ◽  
A Site

Two general classes of light-evoked responses were recorded intracellularly from the retina of Strombus luhuanus. In one class, retinal illumination caused depolarization, the amplitude of which was graded with light intensity. In the other, it produced hyperpolarization and concomitant inhibition of repetitive action potentials. There were two types of depolarizing waveform. Each was associated with a different type of intraccllular recording site, characterized on the basis of electrical properties in the dark. In general, the type of response with a more rapid rate of decay was recorded from a site which exhibited a lower resting potential, higher input resistance, and longer ‘membrane charging time.’ The two depolarizing responses and the hyperpolarizing response apparently each arose from a different type of neurone. The depolarizing types, at least one of which is a photoreceptor, apparently give rise to the cornea-negativity of the electroretinogram and ‘on’ activity in the optic nerve fibres. The hyperpolarizing type apparently mediates ‘off’ activity in the optic nerve.

Movement ofMyzostomum spermatozoa: Calcium ion regulation of swimming direction

1994 ◽  
Vol 28 (2) ◽  
pp. 135-142 ◽  
Author(s):  
Sumio Ishijima ◽  
Sanae A. Ishijima ◽  
Bj�rn A. Afzelius
Keyword(s):  
Calcium Ion ◽  
Ion Regulation ◽  
Swimming Direction

scholarly journals An unsuccessful attempt to elicit orientation responses to linearly polarized light in hatchling loggerhead sea turtles ( Caretta caretta )

2011 ◽  
Vol 366 (1565) ◽  
pp. 757-762 ◽  
Author(s):  
Lydia M. Mäthger ◽  
Kenneth J. Lohmann ◽  
Colin J. Limpus ◽  
Kerstin A. Fritsches
Keyword(s):  
Light Field ◽  
Uv Light ◽  
Light Emitting Diode ◽  
Sea Turtles ◽  
Polarized Light ◽  
Caretta Caretta ◽  
Polarization Sensitivity ◽  
Light Perception ◽  
Unsuccessful Attempt ◽  
Swimming Direction

Sea turtles undertake long migrations in the open ocean, during which they rely at least partly on magnetic cues for navigation. In principle, sensitivity to polarized light might be an additional sensory capability that aids navigation. Furthermore, polarization sensitivity has been linked to ultraviolet (UV) light perception which is present in sea turtles. Here, we tested the ability of hatchling loggerheads ( Caretta caretta ) to maintain a swimming direction in the presence of broad-spectrum polarized light. At the start of each trial, hatchling turtles, with their magnetic sense temporarily impaired by magnets, successfully established a steady course towards a light-emitting diode (LED) light source while the polarized light field was present. When the LED was removed, however, hatchlings failed to maintain a steady swimming direction, even though the polarized light field remained. Our results have failed to provide evidence for polarized light perception in young sea turtles and suggest that alternative cues guide the initial migration offshore.

scholarly journals Swimming direction reversal of flagella through ciliary motion of mastigonemes

2011 ◽  
Vol 5 (3) ◽  
pp. 034108 ◽  
Author(s):  
S. Namdeo ◽  
S. N. Khaderi ◽  
J. M. J. den Toonder ◽  
P. R. Onck
Keyword(s):  
Swimming Direction ◽  
Ciliary Motion ◽  
Direction Reversal

scholarly journals Negative Geotaxis in Sea Urchin Larvae: A Possible Role of Mechanoreception in the Late Stages of Development

1988 ◽  
Vol 137 (1) ◽  
pp. 141-156 ◽  
Author(s):  
Yoshihiro Mogami ◽  
Chieko Oobayashi ◽  
Tomoko Yamaguchi ◽  
Yumi Ogiso ◽  
Shoji A. Baba
Keyword(s):  
Control Systems ◽  
Sea Urchin ◽  
Developmental Stages ◽  
Dark Field ◽  
Physiological Control ◽  
Swimming Direction ◽  
Early Stages ◽  
Late Stages ◽  
Pluteus Stage

Negative geotactic behaviour of sea urchin larvae at various developmental stages from blastula to pluteus was analysed by means of time-exposure dark-field photography of the swimming behaviour of individual larvae. Significant differences in the patterns of behaviour, such as swimming direction and speed, were demonstrated between the early stages (up to the gastrula) and the pluteus, although larvae at any developmental stage showed negative geotactic migration. Larvae in the early stages swam at speeds that varied as a function of the swimming direction with respect to gravity, faster downwards and slower upwards. This might be predicted from the assumption that vertical locomotion is determined by constant propulsion affected passively by gravity. In the pluteus stage, however, larvae swam at a constant speed in any direction, suggesting that the propulsive activity of swimming plutei is actively controlled depending on the swimming direction. This change in the negative geotactic behaviour of sea urchin larvae in the course of embryogenesis indicates development of physiological control systems for propulsive activity at the pluteus stage.

scholarly journals Effects of Currents on Human Freestyle and Breaststroke Swimming Analyzed by a Rigid-Body Dynamic Model

Machines ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 17
Author(s):  
Yinxiang Bao ◽  
Hongbin Fang ◽  
Jian Xu
Keyword(s):  
Dynamic Model ◽  
Human Body ◽  
Swimming Performance ◽  
Open Water ◽  
Underlying Mechanism ◽  
Modeling And Analysis ◽  
Rigid Body Dynamic ◽  
Swimming Direction ◽  
Parametric Analyses ◽  
Multi Body

Swimming is a kind of complex locomotion that involves the interaction between the human body and the water. Here, to examine the effects of currents on the performance of freestyle and breaststroke swimming, a multi-body Newton-Euler dynamic model of human swimming is developed. The model consists of 18 rigid segments, whose shapes and geometries are determined based on the measured data from 3D scanning, and the fluid drags in consideration of the current are modeled. By establishing the interrelations between the fluid moments and the swimming kinematics, the underlying mechanism that triggers the turning of the human body is uncovered. Through systematic parametric analyses, the effects of currents on swimming performance (including the human body orientation, swimming direction, swimming speed, and propulsive efficiency) are elucidated. It reveals that the current would turn the human body counterclockwise in freestyle swimming, while clockwise in breaststroke swimming (which means that from the top view, the human trunk, i.e., the vector pointing from the bottom of feet to the top of the head, rotates counterclockwise or clockwise). Moreover, for both strokes, there exists a critical current condition, beyond which, the absolute swimming direction will be reversed. This work provides a wealth of fundamental insights into the swimming dynamics in the presence of currents, and the proposed modeling and analysis framework is promising to be used for analyzing the human swimming behavior in open water.

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