TitleWATER DETECTION IN THE DESERT SAND SCORPION, PARUROCTONUS-MESAENSIS (SCORPIONIDA, VAEJOVIDAE)
Publication TypeJournal Article
Year of Publication1992
AuthorsGaffin, DD, Wennstrom, KL, Brownell, P
JournalJournal of Comparative Physiology a-Sensory Neural and Behavioral Physiology
Volume170
Pagination623-629
Type of ArticleJournal Article
ISSN0340-7594
Abstract

For the sand scorpion, Paruroctonus mesaensis, substrate moisture is a powerful and fast-acting stimulus of discrete behaviors related to localization and imbibitory uptake of water. These behaviors are readily observed in the field and quantified in the laboratory when free-roaming animals encounter sand substrates dampened by small amounts of water. Of 10 behaviors we monitored in laboratory tests, 5 (pedipalp-pull, rototiller-digging, prolonged stops, headstand, and backing-up) occurred only after contact with a moistened substrate. These water-stimulated behaviors were selectively blocked when all 8 tarsal leg segments were coated with wax; coverings of the chemosensory pectine appendages had little to no effect. Electrophysiological recordings from chemoreceptor organs on the tarsi showed that neurons innervating the dorsal tarsal organ, were highly sensitive to humid air stimuli while the numerous, pore-tipped hairs on the ventral surface were responsive to aqueous solutions applied directly to their tips. Selective blocking of the 8 tarsal organs had no effect on water sensitive behavior indicating that the chemosensory hairs mediate detection of substrate moisture. Such localized, sensory triggering of a robust and directed behavior presents a useful model for further neuroethological studies.

URL<Go to ISI>://WOS:A1992HZ66100008