Do the length-weight relationships and condition factors of farmed rainbow trout, brook, and brown trout differ from their wild counterparts?

Abstract

This study examines the length-weight relationships (LWR) and condition factors (CF) of three farmed fish species: rainbow trout (Oncorhynchus mykiss), brook trout (Salvelinus fontinalis), and brown trout (Salmo trutta). It then compares these findings with existing literature data for their wild counterparts to gain insights into the influence of aquaculture on their growth patterns. Using a simple power function, W=α〖L_T〗^β where W represents the fish's weight, and LT represents the fish's total length, the LWR is determined. The estimated β values indicate positive allometric growth for rainbow and brook trout, whereas brown trout exhibit an isometric growth pattern. The estimated condition factors ranged from 0.992 to 1.442 for rainbow trout, 0.665 to 1.731 for brook trout, and 0.841 to 1.321 for brown trout, with significant differences observed among them (Kruskal-Wallis test, p < 0.05). Compared with literature data from their wild counterparts, notable variations in growth patterns emerge, particularly evident in rainbow and brook trout, possibly illustrating the contrasting effects of aquaculture.