Fish feed can show genotoxic damage

Area of Science:

• Aquaculture
• Fish Physiology
• Genotoxicology

Background:

• Nutritional quality of fish feed is crucial for aquaculture success.
• Assessing feed genotoxicity is vital for fish health and sustainable aquaculture.
• Erythrocytic nuclear abnormalities serve as biomarkers for genotoxicity.

Purpose of the Study:

• To evaluate the genotoxic potential of commercial fish feeds.
• To correlate erythrocytic nuclear abnormalities with nutrient content and fish performance.
• To establish the utility of nuclear abnormalities as an indicator of feed quality.

Main Methods:

• Ten commercial Nile tilapia feeds were tested for digestibility and performance.
• Erythrocytic nuclear abnormalities were analyzed in blood smears after 102 days of feeding.
• Statistical analyses included principal component analysis and correlation matrix.

Main Results:

• Erythrocytic abnormalities, fish performance, and digestibility varied significantly among feeds.
• Higher frequencies of kidney-shaped, bud, bridge, and binuclei were linked to poorer fish performance and correlated with digestible methionine.
• Micronucleus frequency correlated with reduced feed intake and lower zinc levels; vacuolated nuclei correlated with phosphorus levels.

Conclusions:

• Erythrocytic nuclear abnormalities are sensitive indicators of fish health and feed genotoxicity.
• Feed-dependent genotoxic factors were identified, impacting fish health and performance.
• Nuclear abnormality assays are valuable complementary tools for assessing fish feed quality in aquaculture.