Octopus arm movements provide an extreme example of controlled movements of a flexible arm with virtually unlimited degrees of freedom. This study aims to identify general principles in the organization of these movements. Video records of the movements of Octopus vulgaris performing the task of reaching toward a target were studied. The octopus extends its arm toward the target by a wave-like ...

The octopus arm is a muscular hydrostat and due to its deformable and highly flexible structure it is capable of a rich repertoire of motor behaviors. Its motor control system uses planning principles and control strategies unique to muscular hydrostats. We previously reconstructed a data set of octopus arm movements from records of natural movements using a sequence of 3D curves describing the...

St. Joseph Bay, Bay County, Florida, U.S.A. is 1 of 4 locations at which the pygmy octopus, Octopus cf. mercatoris, is known to occur. Octopus densities of 1 per 33 m2 were measured and values of catch per day ranging from 1-70 animals were consistently reported between 1972 and 1999. From 17 August 1999 through 14 October 1999, St. Joseph Bay experienced a severe and prolonged harmful algal bl...

The quasi-static mechanical properties of the aorta of Octopus dofleini were investigated using biaxial inflation and uniaxial force-extension tests on vessel segments in vitro. The octopus aorta is a highly compliant and non-linearly elastic structure. The elastic modulus (i.e. the stiffness) measured circumferentially (Ec) and longitudinally (EL) increased markedly with distension of the vess...

Octopus arms, as well as other muscular hydrostats, are characterized by a very large number of degrees of freedom and a rich motion repertoire. Over the years, several attempts have been made to elucidate the interplay between the biomechanics of these organs and their control systems. Recent developments in electrophysiological recordings from both the arms and brains of behaving octopuses ma...

Arm swimming in the octopus is a mode of locomotion that is used by the animal primarily for hunting, defence, or escape. The motion, in general, is characterized by a fast closing of the arms and a slow opening of the arms, resulting in a considerable propulsive power. The movement has previously been discussed, however the detailed kinematics is still unknown. For that, we investigated in det...

Aim. To compare semikinetic perimetry (SKP) on Octopus 900 perimetry to a peripheral static programme with Humphrey automated perimetry. Methods. Prospective cross-section study comparing Humphrey full field (FF) 120 two zone programme to a screening protocol for SKP on Octopus perimetry. Results were independently graded for presence/absence of field defect plus type and location of defect. Re...

Octopus cells, located in the mammalian auditory brainstem, receive their excitatory synaptic input exclusively from auditory nerve fibers (ANFs). They respond with accurately timed spikes but are broadly tuned for sound frequency. Since the representation of information in the auditory nerve is well understood, it is possible to pose a number of questions about the relationship between the int...