Contribution to the bioecological knowledge of the orange - back squid "Sthenoteuthis pteropus" (Family "Ommastrephidae"; Steenstrup, 1857) for Madeira and Canary waters

Abstract

The presence of Sthenoteuthis pteropus in the Canary and Madeira waters is related to migratory aspects in the months of July and November, coinciding with an increase in sea surface temperature. The range of sizes found in the study area is associated with a part of the life cycle of the squid, not finding small size or large reproductive specimens. Nevertheless, a clear progression of the pigmentation of the beaks was observed, where the individuals began to show a pigmentation change towards the 270-300 mm of Dorsal Mantle Length, which coincides with the onset of gonadal development (i.e sizes to which developed ovaries were started). It should be noted that the presence of males was scarce, with a total of 4 males in relation to 138 females. Feeding was similar to that described by other authors, where the fish presented the greatest numerical importance in the stomach contents. Finally, an analysis of the fishery in the Canary Islands showed that it is a species of seasonal fishing importance, with catches of more than 100 kg / day / boat on the island of La Palma and in Gran Canaria.