Table 2.

Kinematic variables in response to head and tail stimulation with F-ratios and P-values for the two-way ANOVA comparison between stimulus types

VariableHead stimulusTail stimulusF-ratioP-value
Head angle — start to transition (deg.)46.1±10.6375.9±10.93.70850.0721
Head angle — transition to end (deg.)15.2±3.917.1±4.20.14500.7084
Head movement (BL)0.15±0.0170.22±0.0274.59520.0478
Tail movement (BL)0.06±0.0090.35±0.022150.8221 <0.0001
CM movement (BL)0.0046±0.00110.0062±0.00140.69010.4184
Initial body extension (%)81.43±3.2484.29±2.480.51490.4834
Min. body extension (%)66.98±3.1247.71±2.0720.4258 0.0003
Duration total (s)0.195±0.025760.095±0.0122414.4967 0.0015
Duration — start to transition (s)0.077±0.008040.050±0.009378.67860.0095
Duration — transition to end (s)0.118±0.021750.046±0.00711.1637 0.0041
Head velocity (BL s-1)1.001±0.2352.471±0.28618.1784 0.0006
Tail velocity (BL s-1)0.377±0.0793.884±0.286254.9242 <0.0001
CM movement 48 ms post-withdrawal (BL)0.0312±0.01620.14377±0.0298311.1704 0.0041
  • Values for kinematic parameters are means ± s.e.m. Sample size is four individuals, three responses to head stimuli and three responses to tail stimuli per fish. P-values in bold are significant after adjustment of table with a sequential Bonferroni correction (Rice, 1989).