title: Metabolic rate of Arctic charr eggs depends on their parentage.
abstract: The metabolic rate (specific heat output) of individual eyed-stage eggs of Arctic charr Salvelinus alpinus (Linnaeus, 1758) originating from different families was measured with direct microcalorimetry. Metabolic rates varied between 2.3-7.9 microW ind(-1) and 0.06-0.22 microW mg(-1). Absolute heat output was unrelated to egg size, but size-scaled or specific heat output was negatively correlated with egg size, measured as diameter, dry mass or fresh mass. Metabolic rates varied significantly between families, suggesting that genetic and/or maternal effects affect embryonic metabolism in Arctic charr. Heat output increased almost linearly from 3.4 to 16.7 microW ind(-1) (0.09-0.67 microW mg(-1)) during the embryonic development. Although the metabolic rate varied between the families and egg metabolic rate increased during development, there was an unexpected disconnect between metabolic rate and hatching time.
authors.affiliation: Integrative Ecology Unit, Department of Ecology and Systematics, Division of Population Biology, University of Helsinki, P.O. Box 65, 00014, Helsinki, Finland.
authors.forename: Susanna
authors.initials: S
authors.lastname: Pakkasmaa
authors.forename: Olli-Pekka
authors.initials: OP
authors.lastname: Penttinen
authors.forename: Jorma
authors.initials: J
authors.lastname: Piironen
mesh_terms: D000818:Animals; D001481:Basal Metabolism / Q000235:genetics* / Q000502:physiology; D001833:Body Temperature Regulation / Q000235:genetics / Q000502:physiology; D002151:Calorimetry; D047108:Embryonic Development / Q000235:genetics / Q000502:physiology; D004734:Energy Metabolism / Q000235:genetics / Q000502:physiology; D004777:Environment; D005260:Female; D008297:Male; D014337:Trout / Q000235:genetics / Q000502:physiology*; D015053:Zygote / Q000502:physiology*