Parameters for all known standard weight equations.

## Format

A data frame with observations on the following 13 variables:

- species
Species name. Use

`wsVal()`

to see the list of available species.- 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 (Regression Line Percentile (

`RLP`

; see Murphy*et al.*(1990) and Murphy*et al.*(1991)), Empirical Percentile (`EmP`

; see Gerow*et al.*(2005)), 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 equation or the linear coefficient for the quadratic equation.

- quad
The quadratic coefficient in the quadratic equation.

- 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 *et al.* (2012). Species not in Neumann *et al.* (2012) are noted as such in the `comments`

variable.

## 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.

Gerow, K.G., R.C. Anderson-Sprecher, and W.A. Hubert. 2005. A new method to compute standard weight equations that reduces length-related bias. North American Journal of Fisheries Management 25:1288–1300.

Murphy, B.R., M.L. Brown, and T.A. Springer. 1990. Evaluation of the relative weight (Wr) index, with new applications to walleye. North American Journal of Fisheries Management 10:85–97.

Murphy, B. R., D. W. Willis, and T. A. Springer. 1991. The relative weight index in fisheries management: Status and needs. Fisheries (Bethesda) 16(2):30–38.

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.

## Examples

```
str(WSlit)
#> 'data.frame': 205 obs. of 13 variables:
#> $ species: chr "Aegean Chub" "African Sharptooth Catfish" "Alabama Bass" "Ankara Nase" ...
#> $ units : chr "metric" "metric" "metric" "metric" ...
#> $ type : chr "quadratic" "quadratic" "linear" "quadratic" ...
#> $ ref : int 75 75 75 75 75 75 50 75 75 25 ...
#> $ measure: chr "TL" "TL" "TL" "TL" ...
#> $ method : chr "EmP" "EmP" "RLP" "EmP" ...
#> $ min.len: num 70 180 100 70 150 150 160 6 150 70 ...
#> $ max.len: num 220 450 NA 240 NA NA NA NA NA 390 ...
#> $ int : num -3.8 -3.67 -5.6 -10.02 -5.24 ...
#> $ slope : num 1.78 1.89 3.29 7.4 3.08 ...
#> $ quad : num 0.329 0.209 NA -0.971 NA ...
#> $ source : chr "Giannetto et al. (2012)" "Emiroglu et al. (2018)" "Dicenzo et al. (1995)" "Emiroglu et al. (2020)" ...
#> $ comment: chr "none" "only from Sakarya River Basin (Turkey)" "min.len not made clear (assumed same as Spotted Bass); same as Spotted Bass (Alabama subspecies)" "only from Turkey" ...
head(WSlit)
#> species units type ref measure method min.len
#> 1 Aegean Chub metric quadratic 75 TL EmP 70
#> 2 African Sharptooth Catfish metric quadratic 75 TL EmP 180
#> 3 Alabama Bass metric linear 75 TL RLP 100
#> 4 Ankara Nase metric quadratic 75 TL EmP 70
#> 5 Arctic Grayling metric linear 75 TL RLP 150
#> 6 Arctic Grayling metric linear 75 TL EmP 150
#> max.len int slope quad source
#> 1 220 -3.801 1.7830 0.3290 Giannetto et al. (2012)
#> 2 450 -3.668 1.8850 0.2087 Emiroglu et al. (2018)
#> 3 NA -5.598 3.2904 NA Dicenzo et al. (1995)
#> 4 240 -10.017 7.4020 -0.9710 Emiroglu et al. (2020)
#> 5 NA -5.241 3.0830 NA Gilham et al. (2021)
#> 6 NA -5.279 3.0960 NA Gilham et al. (2021)
#> comment
#> 1 none
#> 2 only from Sakarya River Basin (Turkey)
#> 3 min.len not made clear (assumed same as Spotted Bass); same as Spotted Bass (Alabama subspecies)
#> 4 only from Turkey
#> 5 authors note that either RLP or EmP method may be used
#> 6 authors note that either RLP or EmP method may be used
```