Ages of Walleye assigned from otoliths, scales, and spines.

Description

Age of Pymatuning Sanctuary (PA) Walleye (Sander vitreus) assessed from three calcified structures – sectioned otoliths, sectioned dorsal spines, and scale impressions.

Format

A data frame with 61 observations on the following 4 variables:

• otolith: Age (years) assigned from broken, ground, and polished otolith sections

• spine: Age (years) assigned from dorsal spine sections
• scale: Age (years) assigned from scale impressions
• sex: Sex of fish (female and male)

Topic(s)

• Age Comparison
• Age Precision
• Age Bias
• Ageing Error

Note

Relationships between otoliths and spines and otoliths and scales are exact according to Figure 2. Relationship between spines and scales is approximate as Figure 2 did not show this exact relationship.

Source

From Figure 2 in Kocovsky, P.M., and R.M. Carline. 2000. A comparison of methods for estimating ages of unexploited walleyes. North American Journal of Fisheries Management 20:1044-1048.

Examples

data(WalleyePS)
str(WalleyePS)
head(WalleyePS)
op <- par(mfrow=c(3,2),pch=19)
plot(scale~otolith,data=WalleyePS,subset=sex=="female",main="Female")
plot(scale~otolith,data=WalleyePS,subset=sex=="male",main="Male")
plot(scale~spine,data=WalleyePS,subset=sex=="female",main="Female")
plot(scale~spine,data=WalleyePS,subset=sex=="male",main="Male")
plot(spine~otolith,data=WalleyePS,subset=sex=="female",main="Female")
plot(spine~otolith,data=WalleyePS,subset=sex=="male",main="Male")
par(op)