Efficient swimming of biologically carangiform robotic fish has been investigated by using a novel experimental method. The laboratory robotic fish model, which follows an exact replica of Saithe, is self-propelled on a servo towing system. The forward towing speed is determined by the fluid force acting on the robotic fish, as the fish undulates its body in the water. The importance of the sel...

Swimming speed and swimming activity of the nocturnally active benthic amphipod Monoporeia affinis were measured in water temperatures from 3 to 18 degrees C and different population densities in the laboratory. Swimming speed increased with increasing temperature. Increasing water temperature reduced the percentage of active animals in the population, as measured by a "freeze frame" technique....

In six tufted ducks there was a linear relationship between heart rate and oxygen consumption when swimming at different velocities. Mean oxygen consumption at mean duration of voluntary dives was 3*5 times resting and not significantly different from that at maximum sustainable swimming speed. Contrary to an earlier report (Prange & Schmidt-Nielsen, 1970), leg beat frequency increased with inc...

The Wujiang River is a tributary of the upper Yangtze River that shows great variations in its flow regime and habitat condition. Dams have been built along the Wujiang River and have altered the habitats profoundly enough that they may give rise to reproductive isolation. To test whether the swimming performance and morphology of the Chinese hook snout carp (Opsariichthys bidens), varied among...

This study explores the dichotomy between undulatory (passing multiple waves down the fin or body) and oscillatory (flapping) locomotion by comparing the kinematics of pectoral fin locomotion in eight species of batoids (Dasyatis americana, D. sabina, D. say, D. violacea, Gymnura micrura, Raja eglanteria, Rhinobatos lentiginosus and Rhinoptera bonasus) that differ in their swimming behavior, ph...

The desert-dwelling sandfish (Scincus scincus) moves within dry sand, a material that displays solid and fluidlike behavior. High-speed x-ray imaging shows that below the surface, the lizard no longer uses limbs for propulsion but generates thrust to overcome drag by propagating an undulatory traveling wave down the body. Although viscous hydrodynamics can predict swimming speed in fluids such ...

The combination of laser tweezers, fluorescent imaging, and real-time automated tracking and trapping (RATTS) can measure sperm swimming speed and swimming force simultaneously with mitochondrial membrane potential (MMP). This approach is used to study the roles of two sources of ATP in sperm motility: oxidative phosphorylation, which occurs in the mitochondria located in the sperm midpiece and...

Movement characteristics of freely swimming spermatozoa were studied with high-speed cinemicrography. At 21 degrees C, flagellar beat frequency was higher in midcycle human cervical mucus than in native semen or Tyrode's solution; the beat shape differed, possessing diminished amplitude and wavelength. Although the spermatozoa swam straighter in the mucus, the progressive swimming speeds did no...

The attachment of Vibrio alginolyticus to glass surfaces was investigated with special reference to the swimming speed due to the polar flagellum. This bacterium has two types of flagella, i.e., one polar flagellum and numerous lateral flagella. The mutant YM4, which possesses only the polar flagellum, showed much faster attachment than the mutant YM18, which does not possess flagella, indicati...

Negative chemotaxis refers to the motion of microorganisms away from regions with high concentrations of chemorepellents. In this study, we set controlled gradients of NiCl2, a chemorepellent, in microchannels to quantify the motion of Escherichia coli over a broad range of concentrations. The experimental technique measured the motion of the bacteria in space and time and further related the m...