Motility behavior of Azospirillum species in response to aromatic compounds

1994 ◽  
Vol 40 (9) ◽  
pp. 705-711 ◽  
Author(s):  
Geralyne Lopez-de-Victoria ◽  
Donald R. Fielder ◽  
Richard K. Zimmer-Faust ◽  
Charles R. Lovell
Keyword(s):  
Motion Analysis ◽  
Swimming Speed ◽  
Aromatic Compounds ◽  
Rate Of Change ◽  
Behavioral Changes ◽  
Computer Assisted ◽  
Hydroxybenzoic Acid ◽  
Video Motion Analysis ◽  
Azospirillum Brasilense Sp7 ◽  
Azospirillum Lipoferum Sp59b

The motility of Azospirillum lipoferum Sp59b and Azospirillum brasilense Sp7 in the presence of the aromatic compounds benzoate, protocatechuate, 4-hydroxybenzoic acid, and catechol was studied using computer-assisted video motion analysis. Increases in swimming speed with concomitant decreases in the rate of change in direction and increases in path linearity are indicative of bacterial chemoattraction. With the exception of 4-hydroxybenzoic acid, the aromatic compounds tested altered the motility patterns of both species, consistent with a chemoattraction mechanism. 4-Hydroxybenzoic acid elicited significant behavioral changes only in A. brasilense. The highest speeds were recorded for most compounds at concentrations between 1 and 10 mM for A. lipoferum and at lower concentrations for A. brasilense. Catechol, supplied at a 10 mM concentration, reduced the swimming speed of A. brasilense but not of A. lipoferum. The distinct differences in swimming behavior observed between these two species of Azospirillum in response to aromatic compounds may be of ecological significance in soils.Key words: Azospirillum spp., motility, video motion analysis, aromatic compounds.

Computer-assisted video motion analysis: A powerful technique for investigating motility and chemotaxis

1995 ◽  
Vol 23 (3) ◽  
pp. 329-341 ◽  
Author(s):  
Geralyne Lopez-de-Victoria ◽  
Richard K. Zimmer-Faust ◽  
Charles R. Lovell
Keyword(s):  
Motion Analysis ◽  
Computer Assisted ◽  
Powerful Technique ◽  
Video Motion Analysis

The Kinematics of Swimming in Larvae of the Clawed Frog, Xenopus Laevis

1986 ◽  
Vol 122 (1) ◽  
pp. 1-12 ◽  
Author(s):  
KARIN VON SECKENDORFF HOFF ◽  
RICHARD JOEL WASSERSUG
Keyword(s):  
Xenopus Laevis ◽  
Swimming Speed ◽  
High Speed ◽  
Total Mass ◽  
Beat Frequency ◽  
Maximum Amplitude ◽  
Open Water ◽  
Computer Assisted ◽  
Anuran Larvae ◽  
Tail Beat

The kinematics of swimming in larval Xenopus laevis has been studied using computer-assisted analysis of high-speed (200 frames s−1) ciné 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 frequency and speed are positively correlated. 2. Xenopus tadpoles show an increase in the maximum amplitude of the tail beat with increasing velocity up to approximately 6Ls−1. Above that speed amplitude approaches an asymptote at 20 % of body length. 3. Anterior yaw is absent at velocities below 6Ls−1, unlike for other anuran larvae, but is present at higher speeds. 4. At speeds below 6Ls−1 there is a positive linear relationship between length of the propulsive wave (λ) and specific swimming speed. At higher speeds wavelength is constant at approximately 0.8L. 5. There is a shift in the modulation of wavelength and tail beat frequency with swimming speed around 5.6Ls−1, suggesting two different swimming modes. The slower mode is used during open water cruising and suspension feeding. The faster, sprinting mode may be used to avoid predators. 6. Froude efficiencies are similar to those reported for fishes and other anuran larvae. 7. Unlike Rana and Bufo larvae, the axial muscle mass of Xenopus increases dramatically with size from less than 10% of total mass for the smallest animals to more than 45% of total mass for the largest animals. This increase is consistent with maintaining high locomotor performance throughout development.

Intrasubject Reliability of Spinal Range of Motion and Velocity Determined by Video Motion Analysis

1993 ◽  
Vol 73 (9) ◽  
pp. 626-631 ◽  
Author(s):  
Michael E Robinson ◽  
Patrick D O'Connor ◽  
Fred R Shirley ◽  
Michael Mac Millan
Keyword(s):  
Range Of Motion ◽  
Motion Analysis ◽  
Video Motion Analysis

Sperm traits in Chinook salmon depend upon activation medium: implications for studies of sperm competition in fishes

2009 ◽  
Vol 87 (10) ◽  
pp. 920-927 ◽  
Author(s):  
P. Rosengrave ◽  
R. Montgomerie ◽  
V. J. Metcalf ◽  
K. McBride ◽  
N. J. Gemmell
Keyword(s):  
Sperm Competition ◽  
Fresh Water ◽  
Swimming Speed ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Salt Water ◽  
Computer Assisted ◽  
Ovarian Fluid ◽  
Sperm Swimming Speed ◽  
Sperm Traits

Sperm traits of externally fertilizing fish species are typically measured in fresh (or salt) water, even though the spawning environment of their ova contains ovarian fluid. In this study, we measured sperm traits of Chinook salmon ( Oncorhynchus tshawytscha (Walbaum in Artedi, 1792)) in both fresh water and dilute ovarian fluid at 10 and 20 s postactivation, using a computer-assisted sperm analysis system. Spermatozoa swam faster, and had both higher percent motility and a straighter path trajectory for a longer period of forward motility when activated in ovarian fluid compared with activation in fresh water. Comparing sperm activity of 10 males in water versus ovarian fluid, we found a weak but significant correlation for sperm swimming speed at 10 s postactivation (r = 0.34, p = 0.01), but not for any other sperm traits measured. Most important, across males, mean sperm swimming speed in water accounted for <10% of the observed variation in mean sperm swimming speed in ovarian fluid. Thus, we argue that sperm traits measured in fresh water are not particularly relevant to those same traits during normal spawning in this species. We suggest that sperm performance measured in fresh water should be used with caution when comparing the potential for individual males to fertilize ova, especially in studies of sperm competition in externally fertilizing species.

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