The total length (mm) and otolith age of Slimy Sculpin (*Cottus cognatus*) captured in the Arctic Long-Term Ecological Research area were recorded in **SculpinALTER.csv** (view, download, meta).

Use these data, and results from this exercise, to answer the following questions.

- Fit von Bertalanffy’s original parameterization. [
**Hint:**See`vbModels()`

and this supplement.]- Plot TL versus age and superimpose the best-fit VBGF. Comment on model fit.
- Construct a residual plot. Comment on model fit.
- Write the equation for the “original” VBGF with parameters replaced by their estimated values.
- Carefully interpret the meaning of each parameter?
- How does the estimate of \(L_{\infty}\) and \(K\) from fitting this parameterization compare to that from the typical VBGF fit in this exercise. Explain your observation.
- Predict the mean TL, with 95% confidence interval, for an age-3 Slimy Sculpin. How does this prediction compare to the prediction you made using the typical VBGF in this exercise?

from Derek H. Ogle , created 08-Mar-19, updated 26-Dec-21, Comments/Suggestions.