Octopus vulgaris. Paralarval Culture

Abstract

There have been many attempts worldwide to produce in captivity juveniles of Octopus vulgaris, one the most studied cephalopod species in the world because of its very strong market interest. This chapter reviews the different methods used to obtain and maintain broodstocks and the rearing technologies applied to the paralarvae. The main parameters and culture methods to rear the planktonic stage are discussed and a protocol for the rearing of the paralarvae is suggested. The main bottlenecks in the cultivation of this species are emphasized, and further research topics are suggested, including both technical and biological aspects. In laboratory trials, the best growth and survival of the paralarval phase is currently achieved by feeding a mixed live diet composed of enriched Artemia and crustacean zoeae. However, this method is not transferable to a commercial scale as there is limited availability of live zoeae. In order to advance from a research to an industrial scale, it is essential to develop an inert diet with the appropriate nutritional composition to be supplied from an age of 1 month onwards. Another option would be to develop an appropriate enrichment protocol for Artemia so that its composition simulates more closely that of crustacean larvae or wild zooplankton. A protocol for the first month of O. vulgaris paralarvae culture, which allows the production of good-quality individuals (in terms of dry weight and survival) to start the settlement process, is proposed. Relatively high survival rates and paralarvae dry weights of 1.3-1.8 mg can be attained after 1 month on a sole diet of Artemia. These weights are increased to 2.5-3.5 mg when that diet is supplemented with zoeae.