Kinematics of male Eupalaestrus weijenberghi (Araneae, Theraphosidae) locomotion on different substrates and inclines.

摘要: Background The mechanics and energetics of spider locomotion have not been deeply investigated, despite their importance in the life a spider. For example, reproductive success males several species is dependent upon ability to move from one area another. aim this work was describe gait patterns analyze parameters Eupalaestrus weijenberghi (Araneae, Theraphosidae) order investigate mechanisms by which they conserve energy while traversing different inclinations surfaces. Methods Tarantulas were collected marked for kinematic analysis. Free displacements, both level on an incline, recorded using glass Teflon as experimental Body segments animals measured, weighed, center mass experimentally determined. Through reconstruction trajectories body segments, we able estimate internal external mechanical patterns. Results Spiders mainly employed walk-trot gait. Significant differences between first two pairs second detected. No significant detected regarding planes or surfaces with respect duty factor, time lags, stride frequency, length. However, postural changes observed slippery required plane lower than expected. In all conditions, work, within it vertical accounted almost total work. extremely low did rise gradient increased. Discussion Our results support idea considering eight limbs functionally divided into quadrupeds series. anterior composed limbs, explorative steering purpose posterior more involved supporting weight body. unit distance constant among tested. spiders showed values Minimizing could help limit metabolic expenditure that, small animals, relatively very high. recovery due inverted pendulum only accounts fraction saved. Adhesive setae present tarsal, scopulae, claw tufts contribute ways during moments step cycle, compensating part energetic cost gradients also maintain parameters.