Editing Rainbow trout (section)

=== Growth and oxidative stress on mitochondria ===
During periods of rapid growth and aging, trout display high levels of metabolic activity. High metabolic activity has been correlated with increased levels of oxidative stress <ref>{{Cite journal|last=Rollo|first=C.D.|date=2002|title=Growth negatively impacts the life span of mammals|journal=Evolution and Development|volume=4|issue=1|pages=55–61|doi=10.1046/j.1525-142x.2002.01053.x|pmid=11868658|s2cid=42123902}}</ref><ref>{{Cite journal|last=Alonso-Alvarez|first=C.|date=2007|title=Increased susceptibility to oxidative damage as a cost of accelerated somatic growth in zebrafinches|journal=Functional Ecology|volume=21|issue=5|pages=873–879|doi=10.1111/j.1365-2435.2007.01300.x|doi-access=free|bibcode=2007FuEco..21..873A }}</ref> and decreased machinery repair <ref>{{Cite journal|last=Almroth|first=B.C.|date=2010|title=Early-age changes in oxidative stress in brown trout, Salmo trutta|journal=Comparative Biochemistry and Physiology, Part B|volume=155|issue=4|pages=442–448|doi=10.1016/j.cbpb.2010.01.012|pmid=20117229}}</ref> in rainbow trout. During high oxidative stress, the [[Mitochondrion|mitochondria]] are the most important organelle contributing to tissue damage because of their role in metabolism and production of [[reactive oxygen species]]. In a study done by Almaida-Pagàn et al.,<ref>{{Cite journal|last=Almaida-Pagàn|first=P.|date=2012|title=Age-related changes in mitochondrial membrane composition of rainbow trout (Oncorhynchus mykiss) heart and brain|journal=Comparative Biochemistry and Physiology, Part B|volume=163|issue=1|pages=129–137|doi=10.1016/j.cbpb.2012.05.013|pmid=22634369|hdl=1893/8959|hdl-access=free}}</ref> researchers identified changes to the heart and brain mitochondrial membrane phospholipid composition in rainbow trout due to the differing levels of oxidative stress each organ faced during a high-stress time such as rapid growth and development. Stock rainbow trout of ages 1, 2, and 4 years had their heart and brain mitochondria isolated and analyzed for fatty acid composition. The tissues showed an overall similar percentage of total phospholipids but differed in the types and proportions of phospholipids. With age, the heart showed more unsaturated phospholipids, which are more susceptible to peroxidation, and thus, damage. The brain mitochondria of rainbow trout show decreased levels of [[docosahexaenoic acid]] and a lower peroxidation index, suggesting a lower susceptibility to damage by oxidative stress and a different reaction to growth compared to heart mitochondria. During the trout's development into an adult, a time of intense growth, the mitochondrial membrane composition and fluidity changes, which can cause defects in the [[electron transport chain]]. These defects combined with altered machinery repair and reactive oxygen species may cause more detrimental effects on the mitochondria in the fish as it matures. {{Clear}}