Collagen from muscle of volador (Illex coindetii), pota (Toradopsis eblanae), and white octopus (Eledone cirrhosa) was characterized in terms of anatomical location, sex, and maturity. Collagen content was higher in arms than in mantle in all three species; there were also significant differences in octopus depending on the age of the individual. Concerning sex, the largest differences in the amount of collagen were found in relation to total protein content. In volador and pota, collagen solubility was higher in the mantle than in the arms, and in the case of pota there were also sex-related differences. In octopus males, solubility was higher in the arms. Two types of collagen, I and V, were identified as the principal constituents in all three species and at both anatomical locations (mantle and arms). The electrophoretic mobility of the alpha2 chain differed in the two types of collagen, but the amino acid compositions of the collagen were similar in the mantle and arms in all three species examined.