Assigned ages, measured fork lengths, and observed sexes for European Perch (Perca fluviatilis) from Lake Tjuekemeer (The Netherlands).
Format
A data frame of 69 observations on the following 3 variables:
- fl
Fork lengths (cm).
- age
Assigned ages.
- sex
Sex (female, male).
Source
From (approximately) Figure 2 in Mooij, W.M., J.M. Van Rooij, and S. Wijnhoven. 1999. Analysis and comparison of fish growth from small samples of length-at-age data: Detection of sexual dimorphism in Eurasian perch as an example. Transactions of the American Fisheries Society, 128:483-490. CSV file
Examples
data(EuroPerchTJ)
str(EuroPerchTJ)
#> 'data.frame': 69 obs. of 3 variables:
#> $ age: int 2 2 2 2 2 2 2 2 2 2 ...
#> $ fl : num 19.8 20.2 20.5 20.9 21.3 21.7 22.1 22.6 23 23.2 ...
#> $ sex: Factor w/ 2 levels "female","male": 2 2 2 2 2 2 2 2 2 2 ...
head(EuroPerchTJ)
#> age fl sex
#> 1 2 19.8 male
#> 2 2 20.2 male
#> 3 2 20.5 male
#> 4 2 20.9 male
#> 5 2 21.3 male
#> 6 2 21.7 male
op <- par(mfrow=c(1,2),pch=19)
plot(fl~age,data=EuroPerchTJ,subset=sex=="female",main="Female")
plot(fl~age,data=EuroPerchTJ,subset=sex=="male",main="Male")
par(op)