Bayesian hierarchical model used to analyze regression between fish body size and scale size: application to rare fish speciesZingel asper

Abstract

Key-words:hierarchical Bayes model, backcalculation, fish, scales, Zingel asper Back-calculation allows to increase available data on fish growth. The accuracy of back-calculation models is of paramount importance for growth analysis. Frequentist and Bayesian hierarchical approaches were used for regression between fish body size and scale size for the rare fish species Zingel asper. The Bayesian approach permits more reliable estimation of back-calculated size, taking into account biological information and cohort variability. This method greatly improves estimation of backcalculated length when sampling is uneven and/or small.

A stage-structured hierarchical Bayes model for the babassu palm tree population dynamics – Estimated from anthropogenic open area data sets

“…This model with two levels of hierarchy (studied area in Benfica and transect) allowed a more reliable estimation of the population dynamics because information is shared between transects to improve the estimation at the level of the studied area and then retrospectively at the transect level. This is a significant improvement over direct empirical estimations using small sample sizes, with missing data and an unbalanced design, Fontez and Cavalli (2014). In our case, the observed stages in transects were unbalanced, as shown in Fig.…”

Growth variation in the endangered fish Zingel asper: Contribution of substrate quality, hydraulics, prey abundance, and water temperature

“…For example, the use of a simple polynomial relationship between body length and scale size to back‐calculate body length, as presented in this study and elsewhere (Danancher et al, 2007), may constitute an over‐simplistic approach largely outweighed by recent Bayesian methods that can account for ecological (e.g. cohort variability; Fontez & Cavalli, 2014) and statistical (e.g. uncertainty during the process of age estimation; Dortel et al, 2013) sources of error in their back‐calculated size estimates.…”

“…a visible area of closely spaced circuli. The strong positive relationship between scale radius and body size repeatedly observed in fishes (Francis, 1990; for Z. asper , see Danancher et al, 2007; Fontez & Cavalli, 2014) makes interannuli distance a reliable and sensitive indicator of past individual growth rates, whereas the total number of annuli on a scale indicates the age of the fish. Once processed, scales were gently cleaned with potassium hydroxide before being mounted between glass slides and analysed under a stereoscopic microscope equipped with an ocular micrometer.…”

“…For example, the use of a simple polynomial relationship between body length and scale size to back-calculate body length, as presented in this study and elsewhere (Danancher et al, 2007), may constitute an over-simplistic approach largely outweighed by recent Bayesian methods that can account for ecological (e.g. cohort variability; Fontez & Cavalli, 2014) (Georget, 2017;Georget, 2019). More broadly, identifying intraspecific variation in life histories is fundamental to enabling a better prediction of the response of endangered species to multivariate environmental stressors and adapting the legislation accordingly.…”