Proposed Standard Weight Equation and Standard Length Categories for Lake Chubsucker

Abstract

Standard weight equations have been proposed for a variety of fishes, including many nongame species. Here, we developed standard weight (W s ) equations for Lake Chubsucker Erimyzon succetta using the traditional regression-line-percentile technique and the newer empirical-percentile method. Length and weight data for 19,727 Lake Chubsuckers from 8 to 42 cm TL and 129 populations were used in the final analysis. These fish were collected from 1977 to 2020 by various agency and university personnel from most known populations across the species' range in North America. This species is considered vulnerable, imperiled, or extirpated in several Midwestern and northern states, but it appears to be secure in the Southeast. The resulting W s equations were log 10 W = −5.0962 + 3.1125 × log 10 L and log 10 W = -5.9735 + 3.8828 × log 10 L −0.1701 × (log 10 L) 2 for the RLP and quadratic empirical-percentile method techniques, respectively, where W is weight (g) and L is total length (TL, mm). The regression-linepercentile equation exhibited a greater length-related bias especially at the ends of the length spectrum, so we recommend the quadratic empirical-percentile equation for this species. We also developed standard length categories for assessing fish population size structure. We propose minimum lengths for five standard length categories of 11, 18, 24, 28, and 35 cm TL for stock, quality, preferred, memorable, and trophy sizes, respectively. Development of a W s equation and standard length categories will aid biologists in assessing condition and size structure of wild Lake Chubsucker populations and those being propagated for supplemental stocking into trophy bass ponds for native forage or in areas with depressed native populations. Additionally, by evaluating this nongame species that occupies the same environments as higher profile game fish species, a more holistic approach of evaluating the overall health of systems can be examined.

Proposed Standard Weight (Ws) Equations and Standard Length Categories for Redbreast Sunfish and Spotted Sunfish

“…However, the Spotted Sunfish world record does not have a recorded length and the Redbreast Sunfish world record is 273 mm TL, which is shorter than some fish found in our data sets. Thus, similar to Bonvechio and Bonvechio (2021), we based our development of the proposed length categories on the longest fish in our data sets for each species.…”

Proposed standard weight (Ws) equation and standard length categories for Goldeye

“…2011; Black et al. 2021; Bonvechio and Bonvechio 2021). The development of a W s equation for Goldeye is needed for size structure and condition evaluations across their range.…”

“…Relative weight is a common metric used to assess body condition in fishes (Wege and Anderson 1978;Murphy et al 1990;Neumann et al 2012) and is determined by dividing the individual weight of a fish by a W s for a given length for that species multiplied by 100 (Wege and Anderson 1978;Anderson and Neumann 1996). Several studies have developed W s equations for nongame native species to aid in their management (Bister et al 2000;Didenko et al 2004;Richter 2007;Neely et al 2008;Quist et al 2011;Black et al 2021;Bonvechio and Bonvechio 2021). The development of a W s equation for Goldeye is needed for size structure and condition evaluations across their range.…”

“…Proportional size distribution is a convenient index for quantifying length-frequency distributions among populations for various species (Wege and Anderson 1978;Weithman 1978;Gabelhouse 1984). Gabelhouse (1984) used all-tackle world-record lengths listed by the International Game Fish Association to define minimum lengths for five size categories for many sport fish species, but recent studies have proposed accepted values for other species not initially included (Quist et al 1998;Bonvechio et al 2010;Dumont and Neely 2011;Bonvechio et al 2019;Kim et al 2019;Black et al 2021;Bonvechio and Bonvechio 2021;Bonvechio et al 2023). However, PSD categories have not been developed for Goldeye.…”