Electrophysiological and Behavioral Responses of Elongated Solifuge Sensilla to Mechanical Stimuli

Authors

Pallabi Kundu, University of Nebraska-Lincoln and Institute for Integrative ConservationFollow
Mariela Oviedo-Diego, Universidad Nacional De Córdoba and Instituto De Diversidad y Ecología Animal
Franco Cargnelutti, Universidad Nacional De Córdoba and Instituto De Diversidad y Ecología Animal
R. Ryan. Jones, University of Colorado Denver
Erika Garcia, University of Colorado Denver
Eileen A. Hebets, University of Nebraska-Lincoln
Douglas D. Gaffin, University of Oklahoma Norman Campus

ORCID IDs

Kundu https://orcid.org/0009-0006-4334-7516

Oviedo-Diego https://orcid.org/0000-0002-4469-6244

Cargnelutti https://orcid.org/0000-0002-6039-4510

Jones https://orcid.org/0000-0002-0174-9705

Garcia https://orcid.org/0000-0002-5818-5795

Hebets https://orcid.org/0000-0002-9382-2040

Document Type

Article

Date of this Version

2025

Citation

Journal of Comparative Physiology A (2025) 211: 277–292

doi: 10.1007/s00359-025-01731-y

Comments

Open access

License: CC BY 4.0

Abstract

A fundamental understanding of animal sensory systems is crucial for comprehending their interactions with the environment and with other conspecifics. However, knowledge gaps persist, particularly in arachnids like the order Solifugae. While certain solifuge setae and palpal papillae have been studied structurally and electrophysiologically, providing evidence of chemoreception and mechanoreception, the sensilla on their walking legs remain unexplored. Notably, elongated sensilla on the femur and tibia of the 4th walking legs resemble trichobothria in other arachnid orders yet their function remains unknown. Thus, this study investigates whether these sensilla serve a mechanosensory function. Using electrophysiological and behavioral assays on Eremobates pallipes (Eremobatidae), we assessed the response of the elongated 4th leg sensilla to– (i) air particle movement and– (ii) air pressure changes. Air particle movement stimuli were generated using a speaker placed in the near field of the elongated sensilla that emitted low-frequency pure tones (10–1000 Hz). Air pressure stimuli involved forceful blowing on the sensilla. No response to air particle movement was observed, but a mechanosensory response to air pressure stimuli was detected. Electrophysiological data identified a fast-adapting and fast-recovering cell, and behavioral observations revealed a startle response. Our electrophysiology results suggest a mechanosensory role of elongated sensilla on the 4th walking legs of solifuge, indicating that although they are not sensitive enough to detect air particle movement stimuli, they can receive and respond to air pressure stimuli. Our behavioral experiments similarly show that these sensilla are not sensitive enough to detect air particle movement but respond to more forceful mechanosensory stimuli.