Are squid rings made from squids? Amplicon-sequencing HTPS method to identify cephalopod species in processed squid products

Cephalopods are widely consumed marine species, yet their fisheries remain poorly regulated, and species-specific catch data are often unavailable. Although a variety of processed squid products are available on the market, frozen squid rings and pieces are among the most popular in the EU and other countries worldwide. This study aimed to assess the diversity of cephalopod species in these processed squid products sold in the Spanish market and to evaluate their compliance with EU labelling regulations. We analysed the labelling and species composition of 63 commercial products by examining their adherence to EU labelling requirements and identifying the cephalopod species present in them by using a metabarcoding approach based on High Throughput Sequencing (HTS). While mislabelling rates were relatively low (11.1%), we observed a high diversity of commercial names that could mislead consumers. Products labelled simply as “squid” included species from both the Loliginidae and Ommastrephidae families, with 50% containing Jumbo flying squid ( Dosidicus gigas ). These findings underscore the need for clearer labelling to ensure transparency and promote sustainable seafood consumption.