Effects of temperature, dissolved oxygen, and substrate on the development of metabolic phenotypes in age-0 lake sturgeon (Acipenserfulvescens): implications for overwintering survival

The impact of early rearing environment on phenotypic development in teleosts has been reasonably well-documented, but only recently has attention been paid to sturgeon raised for conservation purposes. In the present study, we hypothesized that rearing environment will result in the development of distinct metabolic phenotypes in age-0 lake sturgeon (Acipenserfulvescens) and that these phenotypes will drive differential survival rates during a simulated overwintering event. Lake sturgeon gametes were fertilized and raised in one of three different environments: 16[degrees]C +100% dissolved oxygen (DO), 14[degrees]C + 100% DO, and 16[degrees]C + 80% DO, each with or without substrate. We measured standard metabolic rate, forced maximum metabolic rate, metabolic scope, energy density, hepatosomatic index, Fulton's condition factor, and enzyme activities associated with ATP production. Our results suggest that subtle changes in abiotic environments during early life history result in the development of distinct metabolic phenotypes during the first year of life. These have important implications for survival of age-0 lake sturgeon when stocked in the fall of their first year. Si l'incidence du milieu de grossissement precoce sur le developpement phenotypique chez les teleosteens est raisonnablement bien documentee, ce n'est que recemment qu'une attention a ete portee aux esturgeons eleves a des fins de conservation. Nous avons postule que differents milieux de grossissement se traduiraient par le developpement de differents phenotypes metaboliques chez les esturgeons jaunes (Acipenserfulvescens) de 0 an et que ces phenotypes produiraient des taux de survie differents durantun episode d'hivernage simule. Des gametes d'esturgeon jaune ont ete fertilises et eleves dans l'un des trois milieux suivants: 16[degrees]C +100 % d'oxygene dissous (OD), 14[degrees]C +100 % OD et 16[degrees]C + 80 % OD, avec ou sans substrat. Nous avons mesure le metabolisme standard, le metabolisme maximum force, la portee metabolique, la densite energetique, l'indice hepatosomatique, le coefficient de condition de Fulton et des activites enzymatiques associees a la production d'ATP. Nos resultats portent a croire que de petites variations du milieu abiotique au debut du cycle biologique se traduisent par le developpement de phenotypes metaboliques distincts durant la premiere annee de vie. Ces differents phenotypes ont une importante incidence sur la survie des esturgeons jaunes de 0 an ensemences a l'automne de leur premiere annee. [Traduit par la Redaction]
Introduction Conservation aquaculture is a common approach used towards improving the status of fish populations at risk. Much investment has been made in this area in association with conservation efforts [...]