Differences in the metabolic response to temperature acclimation in nine‐spined stickleback (Pungitius pungitius) populations from contrasting thermal environments

Abstract

Metabolic responses to temperature changes are crucial for maintaining the energy balance of an individual under seasonal temperature fluctuations. To understand how such responses differ in recently isolated populations (<11,000 years), we studied four Baltic populations of the nine-spined stickleback (Pungitius pungitius L.) from coastal locations (seasonal temperature range, 0-29°C) and from colder, more thermally stable spring-fed ponds (1-19°C). Salinity and predation pressure also differed between these locations. We acclimatized wild-caught fish to 6, 11, and 19°C in common garden conditions for 4-6 months and determined their aerobic scope and hepatosomatic index (HSI). The freshwater fish from the colder (2-14°C), predator-free pond population exhibited complete temperature compensation for their aerobic scope, whereas the coastal populations underwent metabolic rate reduction during the cold treatment. Coastal populations had higher HSI than the colder pond population at all temperatures, with cold acclimation accentuating this effect. The metabolic rates and HSI for freshwater fish from the pond with higher predation pressure were more similar to those of the coastal ones. Our results suggest that ontogenic effects and/or genetic differentiation are responsible for differential energy storage and metabolic responses between these populations. This work demonstrates the metabolic versatility of the nine-spined stickleback and the pertinence of an energetic framework to better understand potential local adaptations. It also demonstrates that instead of using a single acclimation temperature thermal reaction norms should be compared when studying individuals originating from different thermal environments in a common garden setting.

Multigenerational exposure to elevated temperatures leads to a reduction in standard metabolic rate in the wild

“…By measuring metabolic rates across a range of temperatures, rather than a single temperature as is typically done (Bruneaux et al 2014), we were able to compare the steepness of the metabolic reaction norms of warm versus cold populations. In terms of SMR, warm-habitat sticklebacks had a steeper metabolic rate reaction norm than coldhabitat sticklebacks in the allopatric population pair but a less steep reaction norm in sympatric population 1.…”

Prediction of harmful variants on mitochondrial genes: Test of habitat‐dependent and demographic effects in a euryhaline fish

“…In addition to mitochondrial genome sequencing, 462 individuals from five freshwater and five brackish water populations were initially screened at 12 microsatellite loci (Bruneaux et al., ; Table ). However, three loci were removed from the final data analysis because of significant deviations from the Hardy–Weinberg equilibrium ( p < .001).…”

“…Basic descriptive sequence statistics for the complete mitogenome and mitochondrial OXPHOS genes were calculated usingDnaSP v.5.1(Librado & Rozas, 2009) and PopGenome v.2.6.1(Pfeifer, Wittelsburger, Ramos-Onsins, & Lercher, 2014) in R v.3.2.5 (R Core Team 2016. The individual samples from six freshwater (n = 26) and six brackish water (n = 31) populations were pooled for further statistical analyses to obtain separate mtDNA diversity estimates for freshwater and brackish water habitats.In addition to mitochondrial genome sequencing, 462 individuals from five freshwater and five brackish water populations were initially screened at 12 microsatellite loci(Bruneaux et al, 2014;…”

Is there plasticity in developmental instability? The effect of daily thermal fluctuations in an ectotherm

“…Our observed decline in metabolic rate under fluctuating temperature mirrors previous studies (Chen & Stillman, ; Chown, Haupt, & Sinclair, ; Niehaus, Wilson, Seebacher, & Franklin, ). According to theories on metabolic homeostasis (“metabolic cold adaptation”; White et al., ; Bruneaux et al., ), animals should acclimate through downregulation of MR at high temperatures to counter the passive thermal increase in metabolism (Clarke & Johnston, ; Kielland et al., ). However, they should also upregulate MR at low temperatures.…”