Effect of external carbon dioxide concentration on electric organ dischargge frequency by the gymnotiform fish Apteronotus albifrons

RESUMO

A model is described for the instantaneous frequency (F) of electric organ discharge in Apteronotus albifrons F=H/(aH + b), where a and b are linear parameters and H, hydrogen ion concentration, pH from 7.10 to 4.89 was modified by increasing external carbon dioxide concentrations. With the increase in pH from 5.17 to 7.40, corresponding to a decrease of carbon dioxide concentration, the equation was as follows F=(logH)/(a ,log H=b). The model search consisted of the adjustment of a simple linear regression using fucntion transformation for the most adequate residue analysis by the Durbin-Watson test. The parallelism was checked by comparing regression lines with homogeneous variances and using other tests for non-homogeneous variances