Ages of Alewife (Alosa pseudoharengus) assessed from otoliths and scales.
Format
A data frame of 104 observations on the following 2 variables:
- otoliths
Age assigned from examination of otoliths
- scales
Age assigned from examination of scales
Source
From Table 1A of Hoenig, J.M., M.J. Morgan, and C.A. Brown. 1995. Analysing differences between two age determination methods by tests of symmetry. Canadian Journal of Fisheries And Aquatic Systems, 52:364-368. Originally from O'Gorman, R., D.H. Barwick, and C.A. Bowen. 1987. Discrepancies between ages determined from scales and otoliths for alewives from the Great Lakes. pp. 203-210 In. Summerfelt, R.C. and G.E. Hall (Eds.) Age and Growth of Fish. Iowa State University Press, Ames, IA. CSV file
Examples
data(AlewifeLH)
str(AlewifeLH)
#> 'data.frame': 104 obs. of 2 variables:
#> $ otoliths: int 0 0 1 1 1 1 1 1 1 1 ...
#> $ scales : int 0 0 0 1 1 1 1 1 1 1 ...
head(AlewifeLH)
#> otoliths scales
#> 1 0 0
#> 2 0 0
#> 3 1 0
#> 4 1 1
#> 5 1 1
#> 6 1 1
plot(scales~otoliths,data=AlewifeLH)
xtabs(~otoliths+scales,data=AlewifeLH)
#> scales
#> otoliths 0 1 2 3 4 5 6
#> 0 2 0 0 0 0 0 0
#> 1 1 14 3 0 0 0 0
#> 2 0 0 16 4 0 0 0
#> 3 0 0 2 11 0 0 0
#> 4 0 0 0 5 12 1 0
#> 5 0 0 0 2 4 4 0
#> 6 0 0 0 1 3 2 2
#> 7 0 0 0 0 1 5 1
#> 8 0 0 0 0 1 4 0
#> 9 0 0 0 0 0 0 1
#> 10 0 0 0 0 0 0 2