Identification of fish species using random amplified polymorphic DNA (RAPD)

Area of Science:

• Molecular Biology
• Ichthyology
• Forensic Science

Background:

• Accurate fish species identification is crucial for regulatory compliance, food authenticity, and ecological monitoring.
• Traditional identification methods can be time-consuming and may not be effective for processed or damaged samples.

Purpose of the Study:

• To evaluate the efficacy of the Random Amplified Polymorphic DNA (RAPD) technique for identifying eight different fish species.
• To determine if RAPD can reliably distinguish between closely related species and identify mislabeled fish products.

Main Methods:

• Analysis of 116 fish specimens from eight species: barramundi, Nile perch, john dory, mirror dory, silver dory, spikey oreo, warty oreo, and smooth oreo.
• Generation of Random Amplified Polymorphic DNA (RAPD) profiles using polymerase chain reaction.
• Resolution of DNA profiles via agarose gel electrophoresis and confirmation with native polyacrylamide gel electrophoresis (PAGE) on a DNA sequencer.

Main Results:

• RAPD profiles were consistent within verified barramundi samples.
• Whole barramundi, including imported fish, produced expected RAPD profiles.
• Four of six barramundi fillets did not match the typical barramundi profile; three matched Nile perch.
• Species-specific RAPD profiles were generated for all seven other species tested.
• One john dory fillet did not match authenticated samples.

Conclusions:

• The Random Amplified Polymorphic DNA (RAPD) method is a reliable tool for fish species identification.
• RAPD can detect mislabeled or adulterated fish products, particularly in processed forms like fillets.
• This molecular technique offers a robust alternative for species verification in fisheries and food safety.