Early Thermal Experience has Different Effects on Growth and Muscle Fibre Recruitment in Spring- and Autumn-Running Atlantic Salmon Populations

Abstract

The consequence of early thermal experience for subsequent growth patterns was investigated in Atlantic salmon (Salmo salar L.). Spring- and autumn-running salmon were caught in upland (Baddoch) and lowland (Sheeoch) tributaries of the River Dee, Aberdeenshire, Scotland, respectively, on the final stages of their spawning migrations. The eggs were incubated at the simulated natural temperature regime of each stream, which was on average 2.8 degrees C lower for the Baddoch. The offspring, representing 11 families per population, were transferred at first feeding to constant environmental conditions (12–14 degrees C; 16h:8h light:dark photoperiod) and reared in replicate tanks. Salmon of both populations were longer and heavier at 6 and 12 weeks in fish initially reared under the cooler Baddoch regime. Length frequency distributions became bimodal after 18 weeks, and only the upper growth mode was studied. Modelling of length distributions at 40 weeks revealed significantly different patterns of muscle growth according to initial temperature regime, but only for the Sheeoch salmon. In fish of Sheeoch origin, significantly more white muscle fibres were recruited per mm(2) increase in myotomal cross-sectional area at Sheeoch than at Baddoch temperatures (P<0.01). After 40 weeks, the density of white fibres was 10.4 % higher in fish initially reared at the Sheeoch (533+/−6 mm(−2)) than at the Baddoch (483+/−5 mm(−2)) thermal regimes (means +/− s.e.m., 16 fish per group; P<0.001). Muscle satellite cells were identified using an antibody to c-met. At 24 weeks, the density of muscle satellite cells was 29 % higher in Sheeoch salmon reared to first feeding at the temperature of their natal stream than at cooler Baddoch temperatures (P<0.01). In contrast, the number and size distributions of white muscle fibres in the myotomes of Baddoch salmon were independent of early thermal experience.

Influence of temperature on embryonic development of Pontastacus leptodactylus freshwater crayfish, and characterization of growth and osmoregulation related genes

“…Ιn the Russian sturgeon Acipenser gueldenstaedtii (von Brandt & Ratzeburg 1833) the hatching rate was increased in correspondence to a temperature increase from 12 o C and 16 o C to 20 o C [ 84 ]. Generally, it has been observed that the variability in eggs incubation temperature even in low ranges can lead to substantial changes on the development of embryonic stages [ 85 – 87 ]. Hence, as proposed by Güralp et al [ 88 ], the development and timing of embryonic development and hatching apart from closely related to temperature, is species specific as well.…”

Effects of projected end-of-century temperature on the muscle development of neonate epaulette sharks, Hemiscyllium ocellatum

“…While our analyses found no changes in nuclear recruitment to muscle bers, other studies examining temperate and cold-water teleost shes have seen an increase in myonuclear density with elevated temperatures. When Atlantic salmon, Salmo salar, eggs are reared at temperatures 3-4°C higher than their natal tributary thermal regime, fry exhibit higher nuclear densities and hypertrophic muscle growth shortly after hatching (Johnston et al 2000). Similarly, juvenile Atlantic herring (Clupea harengus), juvenile pacu (Piaractus mesopotamicus), and larval European sea bass (Dicentrarchus labrax) reared under elevated temperatures exhibit higher myonuclear densities, as well as increased hypertrophic and hyperplastic growth rates (Johnston et al 1998b ).…”

A rapid classification tool for deformities in Atlantic salmon (Salmo salar) embryos

“…Salmonid embryos incubate within freshwater sediments, often over winter, and can be subjected to highly variable and potentially harmful conditions within the lake or stream bed ( e.g ., Lavery & Cunjak, 2019). As a result, they may suffer sublethal damage that can affect their fitness in later life stages ( e.g ., Johnston et al ., 2000; Nislow et al ., 2004). For threatened and/or economically valuable species like Atlantic salmon ( Salmo salar ), embryo deformities have particular conservation relevance: deformities in live embryos have been linked to decreased survival later on (suggested by e.g ., Leatherland, 1993, Arias et al ., 1998, Einum et al ., 2002, Eriksen et al ., 2006).…”

“…As a result, they may suffer sublethal damage that can affect their fitness in later life stages (e.g., Johnston et al, 2000;Nislow et al, 2004).…”