Influence of temperature on growth and biochemical-based indicators ofgrowth in juvenile Gobiids of the Baltic Sea

Abstract

Survival and recruitment of marine fish are largely influenced by growth rates, which can be assessed by measuring RNA-DNA ratios as well as macromolecules such as proteins and lipids. Additionally, physical parameters have to be taken into account, which dictate growth rates. For gobies living in the sub littoral area of the Kiel Bight, Western Baltic Sea, temperature is the key abiotic factor, which fluctuates greatly throughout the seasons. In this experiment, two species of juvenile gobies, Pomatoschistus microps and Gobiusculus flavescens, found in the Kiel Bight, were incubated in a temperature-gradient table to determine the influence of temperature on the growth rate and biochemical-based indicators of growth. Growth models were used to analyze the variability in growth and the main body constituents. It was found that lipids are the main determinant of growth in juvenile gobiids and temperature only influences the rate of growth, not the composition of the fish tissue