WSlit: All known standard weight equations.

Description

Parameters for all known standard weight equations.

Arguments

Format

A data frame with observations on the following 13 variables:

species: Species name.
units: Units of measurements. Metric uses lengths in mm and weight in grams. English uses lengths in inches and weight in pounds.
type: Type of equation (linear or quadratic).
ref: Reference quartile (75, 50, or 25).
measure: The type of length measurement used -- total length (TL) or fork length (FL).
method: The type of method used to derive the equation (RLP,EmP, or Other).
min.len: Minimum total length (mm or in, depending on units) for which the equation should be applied.
max.len: Maximum total length (mm or in, depending on units) for which the equation should be applied.
int: The intercept for the model.
slope: The slope for the linear models or the linear coefficient for the quadratic equation.
quad: The quadratic coefficient in the quadratic equations.
source: Source of the equation. These match the sources given in Neumann et al. 2012.
comment: Comments about use of equation.

Source

Most of these equations can be found in Neumann, R.M., C.S. Guy, and D.W. Willis. 2012. Length, Weight, and Associated Indices. Chapter 14 in Zale, A.V., D.L. Parrish, and T.M. Sutton, editors. Fisheries Techniques. American Fisheries Society, Bethesda, MD. Some species were not in Neumann et al (2012) and are noted as such in the comments variable.

Topic(s)

Relative weight
Standard weight
Condition

IFAR Chapter

8-Condition.

Details

The minimum TL for the English units were derived by rounding the converted minimum TL for the metric units to what seemed like common units (inches, half inches, or quarter inches).

References

Ogle, D.H. 2016. Introductory Fisheries Analyses with R. Chapman & Hall/CRC, Boca Raton, FL.

Examples

Run this code

data(WSlit)
str(WSlit)
head(WSlit)

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