Bluefin tuna’s impostor cousin is more common than anticipated?

Escolar is a dark brown color fish which is sometimes marketed as “butterfish”, it grows up to 2m in length. The consumption of Escolar is an issue, the fish cannot metabolize wax esters from its diet. This means the oil contents in its meat consists of 14-25%. The wax esters may cause gastrointestinal distress, AKA diarrhea, which would occur 30-36 minutes after consumption. An example of a consumer’s experience can be found here…

Wired magazine reported a group of scientists working on a research project to identify tuna sushi with DNA barcodes. The group ordered from 31 sushi restaurants and 5 out of those were serving escolar as tuna. Half of those restaurants misrepresented or were unable to clarify the fish they were serving.

The project taken up by the scientists could potentially benefit regulation and penalizing of eateries serving endangered species. The group is currently cataloguing their results in a large database called FISH-BOL. The database has data acquired with specific techniques called DNA Barcoding. Once the database is complete anyone with a handheld DNA reader can easily identify the fish specimen within minutes. This could be greatly beneficial as it would make bluefin tuna easily identifiable, therefore making the enforcement or regulatory consumption easier.

To find out more about the FISH-BOL project go to:

Posted by: Gonzalo Romero