A new generalized depletion model was developed for Octopus vulgaris in Asturias, Spain, considering its rapid life cycle and the co-managed small-scale fishery. Using weekly data from 19 seasons, the model estimates annual recruitment and female spawner emigration. The Shepherd SR model, indicating high density-dependence and overcompensation, was selected. The stock exhibits unstable equilibrium, causing cyclic fluctuations, challenging the applicability of the maximum sustainable yield (MSY). Instead, the study suggests using harvest rates based on mean latent productivity for better sustainability in fluctuating stocks.