{"paper_id":"23751e9d-5ce2-474d-a460-aaaa5a5a4cb8","body_text":"Summary\nThe coleoid cephalopods (octopus, cuttlefish, and squid) are emerging model organisms for neuroscience, development, and evolutionary biology. Determining their sex early in life is critical for population management and controlled experiments. Here, we present a protocol to non-invasively determine the sex of multiple cephalopod species as young as 3 hours post-hatching using a skin swab and quantitative PCR (qPCR). We describe steps for designing qPCR primers, swabbing live animals, extracting DNA, running the qPCR, and analyzing the results. For complete details on the use and execution of this protocol, please refer to Rubino et al.1\nHighlights\nSwab live cephalopods as early as 3 hours post-hatching\nExtract DNA from cephalopod skin swabs\nPerform qPCR-based sex determination\nDesign and validate qPCR primers for new species\nCompeting Interest Statement\nThe authors have declared no competing interest.","source_license":"CC-BY-4.0","license_restricted":false}