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Prey selection in Octopus rubescens: possible roles of energy budgeting and prey nutritional composition

Onthank, Kirt L., Cowles, David L.
Marine biology 2011 v.158 no.12 pp. 2795-2804
Hemigrapsus, Octopodidae, clams, crabs, digestibility, energy content, energy intake, lipids, models, Washington
This study explores the relationship between energy budgeting and prey choice of Octopus rubescens. Seventeen male Octopus rubescens were collected between June 2006 and August 2007 from Admiralty Bay, Washington. Prey choices made by individuals in the laboratory deviated widely from those expected from a simple optimal foraging model. O. rubescens chose the crab Hemigrapsus nudus over the clam Nuttallia obscurata as prey by a ratio of 3:1, even though prey energy content and handling times suggested that this octopus could obtain 10 times more energy intake per unit time when choosing the latter compared to the former prey species. Octopus energy budgets were similar when consuming either of the prey species except for lipid extraction efficiency that was significantly higher in octopuses consuming H. nudus. This suggests that lipid digestibility may play an important role in the prey choice of O. rubescens.