Lipogenesis or Lipidogenesis is the process by which acetyl-CoA is converted to fatty acids. It is intermediate stage in metabolism of simple sugars, such as glucose, which is the source of energy for living organisms. Through Lipogenesis and subsequent Triglyceride synthesis, the energy can be efficiently stored in the form of fats. Lipogenesis encompasses the process of fatty acid synthesis. Triglyceride synthesis is a separate pathway (where fatty acids are esterified with glycerol and form fats). These products are secreted from the liver in the form of very-low-density lipoproteins (VLDL). Thus Created VLDLs are secreted directly into blood where they mature and function to deliver the endogenously derived lipids to the peripheral tissues.

Lipogenesis is controlled and regulated by Insulin is an indicator of the blood sugar level of the body, as its concentration increases proportionally with blood sugar levels. Thus, a large insulin level is associated with the fed state. As one might expect, it increases the rate of storage pathways, such as Lipogenesis. Insulin stimulates Lipogenesis in two main ways: The enzymes pyruvate dehydrogenase (PDH), which forms acetyl-CoA, and acetyl-CoA carboxylase (ACC), which forms malonyl-CoA from acetyl-CoA, are obvious control points. These are activated by insulin. So a high insulin level lead to an overall increase in the levels of malonyl-CoA, which is the substrate required for fatty acids synthesis.

May the diet of the Channa punctatus were rich in insulin, Analyse the Food contents of the animal and quantify the level of insulin in them. Quantify the same in liver of the animal you will get the answer. I hope I have answered your Question

Just a quick comment of Seelam's answer. Insulin is only one of many hormones regulating adiposity. The idea that insulin is present in the fish feed is far-fetched and as insulin is a peptide hormone, ingesting it has no biological effect, as it's broken down in the gastrointestinal tract.

Is adiposity increases accumulation of metal ions in liver? I determine the levels of metal (Cu, Ni, Fe, Co, Mn, Cr, Zn) beyond permissible limits. And also they are high as compared to other fish organs (gills, kidney, muscle, integument).

How do you know that liver adiposity is increasing or that lipidogenesis is occurring in your fish? You don't mention that you've measured and fat-related parameters.

Fish liver can increase in size for many different reasons and it doesn't have to have anything to do with lipid accumulation.

During sexual maturation, the liver size increases as the hepatocytes are actively producing vitellogenin.

During heavy metal exposure, the fish liver is induced to start producing the metal-binding protein metallothionin, and my guess is that this is happening in your fish, resulting in increased liver size.

Sir, i did microtomy and observe the sections of fish liver, hepatocytes showed the presence of lipids. And also the metal accumulation is greatest than other organs so i want to make it clear whether the lipogenesis could play any role in metal accumulation.