Temperature‐induced alterations in hepatocyte structure of rainbow trout (Salmo gairdneri)

Electron microscopic examination showed that hepatocytes from rainbow trout ( Salmo gairdneri ) possess abundant amounts of rough endoplasmic reticulum. Particulate materials, presumably synthesized in the endoplasmic reticulum and transported to the Golgi apparatus, were more numerous in hepatocyte Golgi complexes of trout acclimated at 5° C compared to fish acclimated at 18° C. This temperature‐induced structural modification is thought to reflect an increased secretory activity on the part of the hepatic cell as a result of the organism's adaptation to low temperature.