ISSN:
1432-136X
Keywords:
Black widow
;
Cuticle
;
Cuticularlipids
;
Latrodectus hesperus
;
Water loss-spiders
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary The water permeability of abdominal cuticle of the black widow spiderLatrodectus hesperus was examined using gravimetric, in situ and in vitro techniques. At 30 °C and 0% RH, water loss rates (WLR) of whole, living spiders were higher than in situ WLR measured with capsules secured to the cuticle surface, while in situ WLR of living spiders were greater than in situ WLR for dead spiders. Although these differences are not statistically significant, these results suggest that there may be important extracuticular water loss pathways in living animals, and that the living epidermis does not provide an active barrier to water efflux. In vitro WLR measured on excised pieces of cuticle, in contrast, were nearly 5 times greater than in situ WLR of dead spiders. Temperature/transpiration curves show that permeability increased exponentially with rising temperature, with rates increasing most rapidly between 45 and 51 °C. The WLR for spiders whose cuticle was scrubbed with chloroform: methanol was consistently and substantially (200x) higher than WLR for control or sham-treated spiders. Discussion focuses on the location and composition of the epicuticular lipid water barrier and the potential use of black widow cuticle for in vitro studies of lipid barrier effectiveness in arthropods in general.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00691500
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