Long-term effects of temperature on growth, energy density, whole-body composition and aerobic scope of age-0 Lake sturgeon (A. fulvescens)

Abstract

Fish are known to show high intraspecific phenotypic variation during early life history. Specifically environmental temperature during early life can result in developmental plasticity, which will influence developmental trajectory and ultimately individual fitness. In the present study, we examined long-term effects of early rearing temperature on growth, energy density, body composition (i.e., whole body glucose, triglyceride and protein concentration) and aerobic scope of age-0 Lake Sturgeon (A. fulvescens) to determine if temperature manipulation after yolk absorption would have a long-term impact on these traits. At 58 days post hatch, fish were subjected to one of three temperature manipulations (16 °C; control, 18 °C and ambient river temperature in a range of 14.0–19.4 °C; Ambient) for 35 days after which all fish were raised in Ambient conditions until 360 days post hatch, including 4 months of natural winter temperatures. We hypothesized that temperature conditions experienced before the first winter of life would result in short-term effects of improved growth and energy reserves. Our results showed that temperature manipulation may result in a short-term, reversible effect of improved growth prior to overwintering without a longer-term effect on growth. Enhanced somatic growth of total length and body mass prior to winter did not translate into improved energy reserves, and observed differences in growth rate between treatments did not correlate with aerobic scope. Our data demonstrate that a subtle change in temperature during early life history in Lake Sturgeon may result in short term positive effects on growth rate. These data may enhance current conservation aquaculture operations to promote winter survival in fall released fingerlings without long-term implications on growth phenotypes.