... jet propulsion swimming in cuttlefish is relatively high. Maximal efficiency and power output occur at the cycle frequency used in vivo . Cephalopod Work loop Metabolism Contractile efficiency University of Leeds http://dx.doi.org/10.13039/501100000777 Cephalopod...

..., which has been suggested to be due to the lower efficiency of jet propulsion. The whole-cycle propulsive efficiency of cephalopod molluscs ranges from 38 to 76%, indicating that in some instances jet propulsion can be relatively efficient. Here, we determined the hydrodynamics of hatchling and juvenile...

... for contraction and relaxation, resulting in a lower optimal cycle frequency. During locomotion, the muscles of molluscs undergo cyclical length changes during which they are alternately actively shortened and passively lengthened in order to generate net mechanical work and power; cephalopods, gastropods...

... memory ability has also been demonstrated in the common cuttlefish, a cephalopod mollusc. To explore whether this ability is common to all cephalopods or whether it has emerged to face specific ecological constraints, we conducted an episodic-like memory task with seven Octopus vulgaris . Only one...

...: Intramuscular elastic elements and tensional stress allow for the differential use of arm muscle passive forces during motion in Octopus vulgaris . Cephalopod Muscular hydrostat Motor control Muscle damping Muscle stiffness Muscle elasticity Seventh Framework Programme http://dx.doi.org...

... varies, and the few cephalopod species tested so far have notably acute thresholds of discrimination. However, most studies to date have used artificial sources of polarized light that produce levels of polarization much higher than found in nature. In this study, the ability of octopuses to detect...

...: a phototactic response of extraocular photoreception. Extraocular photoreception has been observed in many and diverse species. Previous research on cephalopods revealed that increased illumination on their skin evokes chromatophore expansion. Recently, the mechanism was investigated and has been termed ‘light...

...; and (iv) shows variability in the intensity of expression of these skin patterns between and within individuals. These data suggest that cephalopods, which are mollusks with an elaborate brain and complex behavior, possess a sleep-like state that resembles behaviorally the vertebrate REM sleep state...

... will impair blood oxygen supply in active squid. Acid–base balance Blood–O 2 binding Hypercapnia Cephalopod Hypoxia tolerance Dosidicus Atmospheric carbon dioxide (CO 2 ) partial pressure ( P CO 2 ) has increased from the pre-industrial mean of 28 Pa (280 μatm, ppmv) to over 40 Pa...

... ; Quijada-Rodriguez et al., 2015 ). However, the role of skin in the removal of nitrogenous waste has not been investigated in cephalopods to date. Wells and Wells (1983) were the first to demonstrate cutaneous oxygen uptake in cephalopods. They found that in addition to branchial oxygen uptake...

... and orientation in squid, resulting in the production of different vortex wake flows. Cephalopod Vorticity Fins Flapping Undulation Proper orthogonal decomposition 3D velocimetry Squid swim, unlike most other nektonic animals, using a combination of coordinated pulsed jetting and fin movements...

... and tail-first, as revealed by 3D jet/fin force and propulsive efficiency measurements. Cephalopod Jet propulsion Fin motion Volumetric velocimetry Wake dynamics Squids swim using a dual-mode system involving a pulsed jet and complex fin motions, both of which are supported and powered...

...M. Desmond Ramirez; Todd H. Oakley ABSTRACT Cephalopods are renowned for changing the color and pattern of their skin for both camouflage and communication. Yet, we do not fully understand how cephalopods control the pigmented chromatophore organs in their skin and change their body pattern...

.... Published by The Company of Biologists Ltd 2015 Cephalopod Chromatophore Flashing Signaling Flickering Crypsis Dosidicus gigas d'Orbigny 1835, commonly known as the Humboldt or jumbo flying squid, is a large pelagic squid of the family Ommastrephidae with a range extending from British...

...Julia E. Samson; T. Aran Mooney; Sander W. S. Gussekloo; Roger T. Hanlon Sound is a widely available and vital cue in aquatic environments, yet most bioacoustic research has focused on marine vertebrates, leaving sound detection in invertebrates poorly understood. Cephalopods are an ecologically...

...Carly A. York; Ian K. Bartol Cephalopods have visual and mechanoreception systems that may be employed to sense and respond to an approaching predator. While vision presumably plays the dominant role, the importance of the lateral line analogue for predator evasion has not been examined...

... Cephalopod Obliquely striated muscle Operating length range Length–force relationship Transmural gradient of strain Hollow, cylindrical muscular organs and bodies are common in animals, especially soft-bodied invertebrates. Such body plans are effective in providing mechanical support for many...

.... supervised all aspects of the project. COMPETING INTERESTS No competing interests declared. 30 4 2013 18 6 2013 © 2013. Published by The Company of Biologists Ltd 2013 Doryteuthis opalescens iridescence iridophore cephalopod male mimicry structural color...

...Lelia Cartron; Ludovic Dickel; Nadav Shashar; Anne-Sophie Darmaillacq SUMMARY Polarization sensitivity is a characteristic of the visual system of cephalopods. It has been well documented in adult cuttlefish, which use polarization sensitivity in a large range of tasks such as communication...

.... No chromatophores are above the ring; this is unusual for cephalopods, which typically use chromatophores to cover or spectrally modify iridescence. The fast flashes are achieved using muscles under direct neural control. The ring is hidden by contraction of muscles above the iridophores; relaxation...