ResultsThe detailed sampling results from the red octopus O. mayabeaks are shown in Table 1. The Increments observed in the beakswere more conspicuous in animals with between 105 and 122 dage because the size of the beak are bigger (Fig. 2); in samples ofoctopuses younger than 105 days of life, definition was lost whilegetting closer to the final segment of the beak. In this portion ofthe beak the segments fold on each other so it was more difficult tocount. This was reflected mainly in the youngest group, which hasa higher value of CV (lower precision; Table 2). In consequence anincrement on precision was obtained with age of octopus (Table 2).The number of beak increments obtained in the present studywas lineally related with the age (Fig. 3). Values of r2and slope closeto 1 were obtained (p < 0.0001). Fig. 4 shows age-BW relationshipfor two data sets, one with ages obtained from beaks analysis anda second group with true ages. Co-variance analysis showed thatthere were no statistical differences between curves obtained bothtypes of data (p > 0.05); for that reason an exponential equation(r2= 0.97) was calculated for the relationship between BW and ageusing both data sets (Fig. 4). This equation was calculated for a BWinterval of 0.13–152 g4