Comparative Pattern of Octopus vulgaris Life Cycle with Environmental Parameters in the Northern Alboran Sea (Western Mediterranean Sea)

Özet

Octopus vulgaris is a short living species with environmental adaptive plasticity and high fecundity. Its abundance canexperience large fluctuations highly dependent on the recruitment success. Both, these abundance fluctuations and thereproductive season seem to be influenced by the variability of environmental conditions which can determine the beginningand the length of the spawning period, the existence of one or several spawning peaks and the length of both the embryonicand planktonic phases. Beside this inter annual variability, the availability of long time series of octopus landings andbiological data can allow us to define a mean or average length for the different phases of the octopus life cycle. Time seriesfor landings, biological and environmental data in the Alboran Sea are analyzed in the present work. Sexual maturity data areused to determine the average spawning season. The ratio of mature females in coastal waters and GSI indicate that spawningoccurs during June, July and August. Temperature time series in the Alboran Sea are used to calculate the length of theembryonic and planktonic phases for O.vulgaris. According to our results, individuals spawned during late spring and summerwould settle during September, October and November, incorporating to the fisheries some weeks later. These results fromour simple model agree with landings time series which show maximum landings from October to January or February.