Squalene Supplementation as a Novel to Increase PUFA Content in Fish Tissues

SIMPLE SUMMARY: The study aimed to assess the effect of squalene supplied in feed on the growth performance, health status, and fatty acid profiles of the muscle and liver of Siberian sturgeon, rainbow trout, and Eurasian perch. To achieve our aim, we fed fish with three feeds containing different levels of squalene (0%, 0,5%, 1%). Then, analyses such as hematological and biochemical assays, liver histology, and fatty acid content of muscle and liver were performed. The results that we obtained indicate changes in the values of hematological, and biochemical indicators between groups. Squalene addition influences the nucleocytoplasmic index values in all fish offered feed containing 1% squalene. The PUFA and docosahexaenoic acid increased with both groups where squalene was added. Exogenous squalene increases the content of PUFAs in the liver and muscles of the examined species. ABSTRACT: Squalene is an antioxidant that plays an essential role in fat metabolism. The study aimed to assess the effect of squalene supplied in feed on the growth performance, health status, and fatty acid profiles of muscle and liver of Siberian sturgeon, rainbow trout, and Eurasian perch. The experimental feeds containing 0%, 0.5%, and 1.0% squalene were prepared for each fish species. Hematological and biochemical indices, liver histology, and fatty acid profiling of muscle and liver were analyzed. Squalene supplementation was safe for fish, and no negative influence on growth status was observed. However, changes in the values of hematological and biochemical indicators were found, including the level of triglycerides in the blood of rainbow trout, and cholesterol in the blood of Eurasian perch. The addition of squalene influences the nucleocytoplasmic index values in all fish offered feed containing 1% squalene. The retention of squalene in the liver and muscle of experimental Siberian sturgeon was observed in both 0.5% and 1.0% squalene levels of feed. The PUFA and docosahexaenoic acid increase was observed in all fish in groups with squalene addition. Dietary squalene increases the content of PUFAs in tissues of the examined species.