Curve walking in freely moving crayfish (Procambarus clarkii)

The curve walking of freely moving crayfish trained to walk along a curved path during homing behaviour was investigated using a video-analysis system. The leg kinematics and leg phase relationships, as well as the relationship between stepping patterns and body axis rotation measured relative to external references, were studied. The anterior and posterior extreme positions of the power stroke (AEP and PEP, respectively) and step amplitudes were analysed. As in a previous study on crayfish curve walking on a treadmill, PEPs were more posterior in outer legs (the legs on the outside of the turn) than in the inner legs. As a result, outer legs showed larger step amplitudes than inner legs. Leg kinematics varied within each walking sequence. AEP leg angles (the angles between the body and leg axes at the AEP) tended to decrease over time for inner legs and increase for outer legs. This leg angle drift was present mainly in the anterior legs and it suggests that these legs did not completely compensate for the body rotation after each step. In addition, leg angle asymmetries in a direction opposite to that of leg angle drift were observed at the start of each curve-walking sequence, suggesting that the extensive training (3 weeks) may have allowed crayfish to anticipate the leg angle drift. The rotational component of curve walking showed a discontinuous pattern, with the animal's body axis turning towards the inside of the curve only periodically. Analysis of cross-correlation functions showed that the angular acceleration of the body axis in the direction of the turn occurred during the power strokes of inner legs 2 and 5 and outer leg 4. While the tripod formed by these three legs showed in-phase relationships, the legs of the corresponding contralateral tripod (outer legs 2 and 5 and inner leg 4) were not in phase. We hypothesize that inner legs 2 and 5 and outer leg 4 act synergically causing the inward body rotation observed in curve-walking crayfish and that some of the asymmetries found in step geometry may be a passive phenomenon due to the body rotation.

[1]  F. Delcomyn.  The Locomotion of the Cockroach Periplaneta Americana , 1971 .

[2]  M. Land.  Stepping movements made by jumping spiders during turns mediated by the lateral eyes. , 1972, The Journal of experimental biology.

[3]  W. Bailey,et al.  Acoustic Orientation in the Cricket Teleogryllus Oceanicus (Le Guillou) , 1977 .

[4]  A. Etienne.  A descriptive and functional analysis of a stereotyped pattern of locomotion after target tracking in a predatory insect , 1977, Animal Behaviour.

[5]  F. Delcomyn.  Neural basis of rhythmic behavior in animals. , 1980, Science.

[6]  W. J. Bell,et al.  Patterns of turning in courtship orientation of the male German cockroach , 1980, Animal Behaviour.

[7]  W. J. Bell,et al.  Rotational locomotion by the cockroach Blattella germanica , 1981 .

[8]  Postural Reflexes Coordinating Walking Legs in a Rock Lobster , 1981 .

[9]  E. Batschelet.  Circular statistics in biology , 1981 .

[10]  F. Clarac,et al.  Decapod Crustacean Leg Coordination during Walking , 1981 .

[11]  Professor Dr. Ulrich Bässler.  Neural Basis of Elementary Behavior in Stick Insects , 1983, Studies of Brain Function.

[12]  Spatial and temporal co-ordination during walking in crustacea , 1984, Trends in Neurosciences.

[13]  W. Barnes,et al.  THE CUTICULAR STRESS DETECTOR (CSD2) OF THE CRAYFISH II. ACTIVITY DURING WALKING AND INFLUENCES ON LEG COORDINATION , 1986 .

[14]  H. Cruse,et al.  Two coupling mechanisms which determine the coordination of ipsilateral legs in the walking crayfish , 1986 .

[15]  H. Cruse.  What mechanisms coordinate leg movement in walking arthropods? , 1990, Trends in Neurosciences.

[16]  Coordination of leg movement in walking arthropods , 1991 .

[17]  R. Blickhan,et al.  Leg design in hexapedal runners. , 1991, The Journal of experimental biology.

[18]  Jeffrey Dean,et al.  Kinematic Model of a Stick Insect as an Example of a Six-Legged Walking System , 1992, Adapt. Behav..

[19]  C. Assaiante,et al.  A statistical approach to sensorimotor strategies: conjugate cross-correlations. , 1994, Journal of motor behavior.

[20]  Zollikofer.  STEPPING PATTERNS IN ANTS - INFLUENCE OF SPEED AND CURVATURE , 1994, The Journal of experimental biology.

[21]  Jamon,et al.  Locomotor patterns in freely moving crayfish (Procambarus clarkii) , 1995, The Journal of experimental biology.

[22]  Full,et al.  Maximum single leg force production: cockroaches righting on photoelastic gelatin , 1995, The Journal of experimental biology.

[23]  Cruse,et al.  Curve walking in crayfish , 1996, The Journal of experimental biology.

[24]  Domenici,et al.  The kinematics and performance of fish fast-start swimming , 1997, The Journal of experimental biology.

[25]  Jamon,et al.  Variability of leg kinematics in free-walking crayfish, Procambarus clarkii, and related inter-joint coordination , 1997, The Journal of experimental biology.

[26]  The contralateral coordination of walking legs in the crayfish Astacus leptodactylus , 1991, Biological Cybernetics.

[27]  H. Cruse,et al.  The contralateral coordination of walking legs in the crayfish Astacus leptodactylus , 1991, Biological Cybernetics.

[28]  J. Camhi,et al.  Organization of a complex movement: fixed and variable components of the cockroach escape behavior , 1988, Journal of Comparative Physiology A.

[29]  F. Clarac,et al.  Basic processes of locomotor coordination in the rock lobster , 1986, Biological Cybernetics.