caa a22 4500 465763782 CHVBK 20180323111907.0 cr unu---uuuuu 170327e19901001xx s 000 0 eng 10.1007/BF00239369 doi (NATIONALLICENCE)springer-10.1007/BF00239369 Body water content and desiccation resistance in some arthropods from subantarctic South Georgia [Elektronische Daten] [R. Ring, W. Block, L. Sømme, M. Worland] Summary: The body water content and resistance to desiccation were studied in two perimylopid beetles, Perimylops antarcticus and Hydromedion sparsutum, a chironomid midge, Eretmoptera murphyi, and two spiders, Notiomaso australis and Perimaso grytvikensis from the subantarctic island of South Georgia. Comparisons were made between different species, different life stages and, where possible, between a high and a low altitude. Perimylops is abundant at higher elevations and in more exposed habitats (fellfields). This may be accounted for by its feeding behaviour, high body water content (relative to Hydromedion) and low rate of water loss under desiccating conditions, particularly in the larval stages. Hydromedion is more abundant at the lower collection site. It is a more robust beetle than Perimylops and its feeding preference is for plants such as grasses and Acaena. Nevertheless, at the upper site adult Hydromedion are able to withstand desiccation to an even greater degree than Perimylops. Water loss rates for both beetles are significantly higher than those reported for related beetles from arid and semi-arid regions. The ability to regulate water loss is not as apparent in the polar perimylopids Perimylops and Hydromedion as in related species from other xeric habitats. These two species, in fact, resemble more closely carabid beetles in xeric habitats in rates of water loss under controlled conditions. Increased temperatures elevate the rate of water loss significantly. South Georgia spiders have a similar rate of water loss to several species of spiders that have been studied in the temperate zone. Eretmoptera is restricted to moist conditions and cannot survive desiccating conditions even for brief periods. It has the highest body water content (78% of fresh weight) of all of the South Georgian arthropods studied. Among the spiders, sufficient information could be obtained only for Notiomaso. This species is much less resistant to desiccation than the perimylopid beetles, and it has a relatively high body water content. It is quite numerous in the lower, warmer habitats where its insect prey is more abundant and diverse. Springer-Verlag, 1990 Ring R. Department of Biology, University of Victoria, V8W 2Y2, Victoria, BC, Canada aut Block W. British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, CB3 OET, Cambridge, UK aut Sømme L. Department of Biology, Division of Zoology, University of Oslo, Blinder, P.O. Box 1050, N-0316, Oslo 3, Norway aut Worland M. British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, CB3 OET, Cambridge, UK aut Polar Biology Springer-Verlag 10/8(1990-10-01), 581-588 0722-4060 10:8<581 1990 10 300 https://doi.org/10.1007/BF00239369 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00239369 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Ring R. Department of Biology, University of Victoria, V8W 2Y2, Victoria, BC, Canada aut NATIONALLICENCE 700 1- Block W. British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, CB3 OET, Cambridge, UK aut NATIONALLICENCE 700 1- Sømme L. Department of Biology, Division of Zoology, University of Oslo, Blinder, P.O. Box 1050, N-0316, Oslo 3, Norway aut NATIONALLICENCE 700 1- Worland M. British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, CB3 OET, Cambridge, UK aut NATIONALLICENCE 773 0- Polar Biology Springer-Verlag 10/8(1990-10-01), 581-588 0722-4060 10:8<581 1990 10 300 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer