Motivated by our desire to understand the biophysical mechanisms underlying the swimming of sperm in the non-Newtonian fluids of the female mammalian reproductive tract, we examine the swimming of filaments in the nonlinear viscoelastic upper convected Maxwell model. We obtain the swimming velocity and hydrodynamic force exerted on an infinitely long cylinder with prescribed beating pattern. We...

—We examined effects of body size and temperature on swimming performance in juvenile estuarine crocodiles, Crocodylus porosus, over the size range of 30–110 cm total body length. Swimming performance, expressed as maximum sustainable swimming speed, was measured in a temperatureand flow-controlled swimming flume. Absolute sustainable swimming speed increased with body length, but length-specif...

In addition to forward undulatory swimming, eels (and some other elongated swimmers) can swim backwards in a similar way. We compared the kinematics (wave speed, cycle frequency, amplitude, local bending and estimated muscle strain) of forward and backward swimming in the European eel Anguilla anguilla. Both swimming modes are characterised by a wave of undulation that travels over the body in ...

0045-7930/$ see front matter Crown Copyright 2 http://dx.doi.org/10.1016/j.compfluid.2012.03.012 ⇑ Corresponding author. Tel.: +82 51 200 7636; fax E-mail address: [email protected] (S. Kang). The propulsion of a bacterial flagellum in a viscous fluid has gained much attention in the field of biological fluid dynamics. Inspired by the bacterial propulsion, we present a three-dimensional computat...

The kinematics of swimming in larval Xenopus laevis has been studied using computer-assisted analysis of high-speed (200 frames s") cine' records. The major findings are as follows. 1. At speeds below 6 body lengths (L) per second, tail beat frequency is approximately 10 Hz and, unlike for most aquatic vertebrates, is not correlated with specific swimming speed. At higher speeds, tail beat freq...

PURPOSE Previous literature has presented pacing data of groups of competition finalists. The aim of this study was to analyze the pacing patterns displayed by medalists and nonmedalists in international competitive 400-m swimming and 1500-m running finals. METHODS Split times were collected from 48 swimming finalists (four 100-m laps) and 60 running finalists (4 laps) in international compet...

Locomotion is crucial for the survival of living organisms, as it allows foraging, flight and mating behaviour. In response to environmental cues, many organisms switch between alternative forms of locomotion, referred to as gaits. The nematode Caenorhabditis elegans exhibits two gaits: swimming in liquids and crawling on dense gels. The kinematics and patterns of muscle activity differ between...

The formation of toxic surface blooms of the motile raphidophyte Heterosigma akashiwo often occurs too quickly to be attributed to cell reproduction. Rapid appearance of surface blooms is more consistent with the hypothesis that a dispersed cell population aggregates at the surface due to a combination of physical factors and swimming behavior. Because of the frequent association of Heterosigma...

BACKGROUND Sex-related differences in performance and in age of peak performance have been reported for freestyle swimming. However, little is known about the sex-related differences in other swimming styles. The aim of the present study was to compare performance and age of peak performance for elite men and women swimmers in breaststroke versus freestyle. METHODS Race results were analyzed ...

Mature female southern elephant seals (Mirounga leonina) come ashore only in October to breed and in January to moult, spending the rest of the year foraging at sea. Mature females may lose as much as 50% of their body mass, mostly in lipid stores, during the breeding season due to fasting and lactation. When departing to sea, post-breeding females are negatively buoyant, and the relative chang...