Skip to Main Content
Table 1.

Comparisons of the electric field strength (log E) where stingrays orient toward and bite at weak electrodes

ParameterModel AModel B
Intercept 1.533*** (0.057) 0.884*** (0.221) 
Urobatis halleri vs Myliobatis californica –0.305** (0.079) –0.190** (0.068) 
Pteroplatytrygon violacea vs Myliobatis californica 0.040 (0.093) 0.088 (0.097) 
Urobatis halleri vs Pteroplatytrygon violacea –0.305** (0.079) –0.190** (0.068) 
Body size 0.021 (0.035) –0.013 (0.030) 
Initial current  0.093** (0.029) 
Turn direction  –0.106* (0.041) 
Electrode number 1 vs –0.099 (0.059) 
Electrode number 2 vs 0.010 (0.059) 
Electrode number 3 vs 0.013 (0.055) 
Gender  0.119 (0.062) 
Variance components   
   Level 1, residual 0.470 (0.020) 0.466 (0.020) 
   Level 2, intercept 0.024 (0.011) 0.010 (0.007) 
Goodness of fit   
   –2 log likelihood 2439.0 2416.0 
   AIC 2451.0 2440.0 
   BIC 2481.3 2500.7 
ParameterModel AModel B
Intercept 1.533*** (0.057) 0.884*** (0.221) 
Urobatis halleri vs Myliobatis californica –0.305** (0.079) –0.190** (0.068) 
Pteroplatytrygon violacea vs Myliobatis californica 0.040 (0.093) 0.088 (0.097) 
Urobatis halleri vs Pteroplatytrygon violacea –0.305** (0.079) –0.190** (0.068) 
Body size 0.021 (0.035) –0.013 (0.030) 
Initial current  0.093** (0.029) 
Turn direction  –0.106* (0.041) 
Electrode number 1 vs –0.099 (0.059) 
Electrode number 2 vs 0.010 (0.059) 
Electrode number 3 vs 0.013 (0.055) 
Gender  0.119 (0.062) 
Variance components   
   Level 1, residual 0.470 (0.020) 0.466 (0.020) 
   Level 2, intercept 0.024 (0.011) 0.010 (0.007) 
Goodness of fit   
   –2 log likelihood 2439.0 2416.0 
   AIC 2451.0 2440.0 
   BIC 2481.3 2500.7 

The multilevel regression Model A is the simplest model comparing the three species whereas Model B includes additional variables. Initial current, turn direction, electrode number and gender have no effect on the differences found between species. The estimate is shown with the s.e.m. in parentheses below(*P<0.05, **P<0.01, ***P<0.001). AIC, Akaike's information criterion; BIC,Schwarz's Bayesian criterion

Close Modal

or Create an Account

Close Modal
Close Modal