Aspects of natural foraging bySepietta oweniana(Mollusca, Cephalopoda)

• Published in: Ophelia
• Main Author: Bergström, Bo I.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Taylor & Francis 1985
• Subjects: Meganyctiphanes norvegica
• Online Access: https://oceanrep.geomar.de/id/eprint/37004/; https://oceanrep.geomar.de/id/eprint/37004/1/2279.pdf; https://doi.org/10.1080/00785236.1985.10426620

The feeding biology of the nectobenthic, sepiolid squid, Sepietta oweniana is treated based on behavioural observations in aquaria and stomach content analyses on 859 trawl caught squid. Juvenile squid in aquaria catch free-swimming prey, preferably the mysid Praunus flexuosus, day and night using the bottom only for shorter resting periods. Adult squid forage from dusk till dawn from positions close to the bottom and spend the day buried in the bottom. Praunus flexuosus is preferred as prey in comparison with demersal and benthic crustaceans as Palaemon elegans and Crangon crangon. Stomach analyses show that in daytime catches, only 16% of all analyzed specimens had stomach contents. Low frequencies were consistent throughout most sampled months in 1979 and 1982. Of the specimens with stomach contents most (50–100%) contained fragments of the euphausiid Meganyctiphanes norvegica. Specimens with remains of decapod shrimps were found in late spring and early summer. It is concluded that S. oweniana feeds in the hyperbenthic habitat at very low light intensities mostly on Meganyctiphanes norvegica in northern waters. A tentative ecological trade off explanation for this apparently inefficient feeding pattern is briefly discussed.