Ages (subsample) and lengths (all fish) for Freshwater Drum from Lake Erie.

A total of 253 fish dispersed proportionately over 10-mm total length intervals from the FWDrumLE1 data frame was obtained for age assignment. The remaining fish in the file were only measured for length (i.e., the ages were deleted). This data file can be used to demonstrate the use of age-length keys.

Format

A data frame with 1577 observations on the following 2 variables.

age

Assigned ages (from scales).

tl

Measured total lengths (mm).

Source

CSV file

Topic(s)

• Age-Length Key

See also

FWDrumLE1.

Examples

data(FWDrumLE2)
str(FWDrumLE2)
#> 'data.frame':	1577 obs. of  2 variables:
#>  $ age: int  3 3 1 4 5 6 3 2 4 1 ...
#>  $ tl : int  212 206 155 285 282 276 264 216 251 135 ...
head(FWDrumLE2)
#>   age  tl
#> 1   3 212
#> 2   3 206
#> 3   1 155
#> 4   4 285
#> 5   5 282
#> 6   6 276
## Extract the aged sample
FWD.aged <- subset(FWDrumLE2,!is.na(age))
str(FWD.aged)
#> 'data.frame':	253 obs. of  2 variables:
#>  $ age: int  3 3 1 4 5 6 3 2 4 1 ...
#>  $ tl : int  212 206 155 285 282 276 264 216 251 135 ...
## Extract the length sample
FWD.length <- subset(FWDrumLE2,is.na(age))
str(FWD.length)
#> 'data.frame':	1324 obs. of  2 variables:
#>  $ age: int  NA NA NA NA NA NA NA NA NA NA ...
#>  $ tl : int  328 320 126 324 325 186 326 326 203 305 ...