Does one size fit all? An evaluation of length–weight relationships for New Zealand's freshwater fish species

Abstract

LengthÁweight relationships are a fundamental tool for assessing populations and communities in fisheries science. Many researchers have collected lengthÁweight data throughout New Zealand, yet parameters describing these relationships remain unpublished for many species of freshwater fish. We compiled 285,124 fish records from researchers and institutions across New Zealand to parameterise lengthÁweight equations, using both power and quadratic models, for 53 freshwater species belonging to 13 families. The influence of location and sex on lengthÁ weight relationships was also assessed. Location, in particular, generated different lengthÁweight relationships for 65% of the species examined. LengthÁweight equations were validated by comparing predicted weights against independently measured weights from 25 electrofished sites across New Zealand and the equations were highly accurate (R 2 0.99). Recommendations are made about how to robustly apply this new resource which should assist freshwater fisheries researchers throughout New Zealand.

The interplay between resource supply and demand determines the influence of predation on prey body size

“…The growth constant 150 reflects growth rate and is clearly responsive to environmental drivers for metabolic demand (Charnov 151 1993 fish species from FishBase (Froese and Pauly 2014) through the auximetric plotting tool. All lengths were 165 converted to mass using the approximate average length-weight regression based on the ranges from 166 Jellyman et al (2013), which was ‫ܯ‬ = expሺ−11ሻ ݈ ଷ . We logged the data and fit them to a power law 167 using reduced major axis regression.…”

Global patterns and clines in the growth of common carp Cyprinus carpio

“…Studies of C . carpio that provided generalized relationships for a certain region or country were also excluded (Jackson et al ., ; Treer et al ., ; Llewellyn, ; Jellyman et al ., ).…”

Length-weight relationships of three estuarine fish species from Bangladesh

“…Length‐weight relationships (LWRs) are basic biological parameters extensively used for estimating approximate weight of a particular species using known length (Baek et al, ; Chaklader, Siddik, Hanif, & Nahar, ; Siddik, Hanif, & Chaklader, ). Moreover, this knowledge can be used for many fisheries biological investigations, i.e., total biomass, fish condition (fatness, feeding and breeding state), age structure, growth rates among areas, regional comparisons of fish life history and species specific environmental suitability (Froese, Tsikliras, & Stergiou, ; Jenllyman, Booker, Crow, & Jellyman, ; Le Cren, ), which are significant for developing fish conservation strategies and ensuring sustainable development (Christensen & Walters, ; Nahar, Hanif, Siddik, Chaklader, & Islam, ; Ricker, ; Siddik, Chaklader, Hanif, Islam, & Fotedar, ). In spite of having different applications, LWRs data are still insufficient for many fish species throughout the world (Froese, & Pauly, ).…”