Vibration sensitivity of pretarsal slit sensilla in the spider leg

摘要: 1. The two single slit sensilla on the pretarsus of spider leg (Cupiennius salei Keys.) are vibration sensitive. Due to their arrangement they also stimulated effectively by active downward movement which may result from muscular activity directly or an increase hemolymph pressure (Figs. 1, 2, 3). 2. The slits not tuned a restricted frequency range. Their threshold displacement was determined electrophysiologically 0.01 Hz 1 kHz and found be higher than in metatarsal organ roughly orders magnitude. The decreases only slightly up about 40 but much more steeply at frequencies. minimal value for within tested range measured 2 × 10−5 cm. acceleration 0.3 10−9 cm/s2 (Fig. 4a). Thresholds vary with different preset tensions cuticle surrounding 5). 3. The shapes curves similar dorsoventral lateral 4b). Values most 3 dB those displacement. 4. As other response pretarsal follows power functiony(f) =fk 7). constantk varies between 0.39 0.44, reflecting receptor properties intermediate frequency-independent amplitude (k = 0) velocity 1). Beyond 10 saturates. Phase locking stimulus is observed 100 (stimuli above threshold).