Ecology of wild Common Octopus: towards SUstainable Management and Aquaculture

The main objective of this project is to investigate in the wild some of the main bottlenecks that prevent the integral rearing of this species: the ecology of the pre-settled plaknktonic paralarvae (with more than 3 suckers per arm) washed to offshore waters offshore as well as the subadults animals (in merobenthic animals, those small animals already settled and with similar proportion than adults, Young and Hartman, 1988) once they reach the fishing ground near the coast. The trophic relationships of the common octopus in these two phases of an area subjected of seasonal upwelling will be investigated to advance towards an ecosystem approach for the management of these socioeconomically important octopod resource as well as to trasfer the data gathered to obtain an integral culture of this socioeconomic important cephalopod.

Octopus vulgaris. Drawing by Gerardo Fernández Carrera.

This general objective include the following specific ones:
• Obtain, for the first time, information of wild paralarvae with a range of 4-22 suckers per arm and the oceanographic influence during this planktonic phase.
• Extend historical series of common octopus paralarvae abundance of newly hatched paralarvae with 3 suckers per arm, which are the only collected during the 20 years monitoring program up to 120 m depth, near the fishing ground, as well as gather information o the influence of chemical, physical and biological parameters of water masses under different scenarios in Galicia. The time series that we already have will also allow us to estimate possible changes in the distribution associated with global warming.
• Estimate age by counting the rings deposited in the beaks of the specimens and try to identify marks of specific life cycle events.
• Study elemental signatures in beaks of subadults (8-200 g) and pre-settled planktonic animals to investigate the settlement strategy that is already unknown in the wild.
• Identify with molecular techniques the pre-settled planktonic paralarvae found offshore the Galician waters and the subadults of this species, collected by scuba diving.
• Comprehend the trophic ecology of the common octopus collected (paralarvae and subadults), their potential preys and pathogenic parasites involved using cutting edge molecular techniques.
• Study the population genetic structure of the zoonotic parasite Anisakis spp. in the mesozooplanktonic realm, and its potential transmission to planktonic predators, including the common octopus.
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• Monitoring the mesozooplankton fraction (0.2-20 mm) to get a concise idea of the zooplankton communities that the different paralarvae inhabit, and test whether they are specialist or generalist predators.
• Quantify home range and identify habitat preferences of octopus juveniles in the wild using acoustic telemetry techniques.
• Create the first biobank on mesozooplankton samples and associated data under a 9001 certification.
• Disseminate the results of the project under a multi–tiered plan to reach, not only the scientific reader but also the general public.
To undertake these aims, we will use data collected during the period of this Project and also historical material and data compiled during the period 2000-2019.