A review on fish growth calculation: multiple functions in fish production and their specific application

Abstract

Modern aquaculture recirculation systems (RASs) are a necessary tool to provide sustainable and continuous aquaculture production with low environmental impact. But, productivity and efficiency of such RAS still have to be optimized to ensure economic viability, putting growth performance into the focus. Growth is often reported as absolute (gain per day), relative (percentage increase in size) or specific growth rate (percentage increase in size per day), based on stocking and harvesting data. These functions describe growth very simplified and are inaccurate because intermediate growth data are not considered. In contrast, nonlinear growth models attempt to provide information of growth across different life stages. On the basis of an empirical RAS data set of 150 all‐female turbot reared in an RAS during a period of 340 days of outgrowth, this paper reviews the most commonly used growth rates (relative, absolute, specific), the thermal‐unit growth coefficient and five nonlinear growth functions (logistic, Gompertz, von Bertalanffy, Kanis and Schnute). Goodness of fit is expressed by R2 and as mean percentage deviation. Nonlinear growth models are also compared by their residual standard error (RSE) and the Akaike information criterion. All processed functions are modelled to illustrate the shape of the generated curve and the possibility of the function to realistically predict growth. Further, the biological meaning of their regression parameters is discussed. This way we can point out differences in nonlinear growth models in contrast to purely descriptive growth rates and the specific advantages, disadvantages and possible applications of each function we review.

Immunomodulatory effects of dietary β-glucan in silver catfish (Rhamdia quelen)

“…The experiments were approved by the Ethics Committee for the Care and Use of Experimental Animals (CEUA, protocol 011/2012) of the Universidade de Passo Fundo. Prior to and after the experiments all fish were weighted and measured to evaluate relative weight gain (WG) and specific growth rate (SGR): WG = 100 x (final weight -initial weight)/initial weight) and SGR = 100 x [ln final weight -ln initial weight]/days of the experiment (Lugert et al 2014).…”

Untitled

“…Currently, the most frequent used models in analyzing fish growth are the von Bertalanfy growth model (Von Bertanlanffy, 1938), the Gompertz growth equation (Gompertz, 1825), and the Logistic function (Ricker, 1975), or the Schnute-Richards model (Schnute & Richards, 1990) (Katsanevakis, 2006). These functions have proven good suitability when displaying growth as a function of age (Lugert et al 2016). However, all of these equations reflect the animal as an output system only (Parks, 1982).…”

Salinity affects growth but not thermal preference of adult mummichogs Fundulus heteroclitus

“…After 12 weeks growth, food was withheld for 24 h and fish were then anesthetised for 24 h before fish were removed, identified, blotted dry and live mass ( M ) and L T recorded. Each fish's relative daily growth rate in mass ( G M ; g g −1 ∙day −1 ) was calculated as: G M = (( M t – M 0 ) M 0 −1 )84 −1 , where M 0 is initial mass and M t is final mass and each fish's relative daily growth rate in length ( G L ; mm mm −1 ∙day −1 ) was calculated as G L = (( L Tt – L T0 ) L T0 −1 )84 −1 , where L T0 is initial length and L Tt is final length (Busacker et al ., ; Logert et al ., ). G M was square‐root transformed to achieve normality (Shapiro‐Wilk test, α = 0.05).…”