کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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2840920 | 1165367 | 2010 | 6 صفحه PDF | دانلود رایگان |
We investigated whether spiders fed lipid-rich rather than protein-rich prey elevate metabolism to avoid carrying excessive lipid deposits, or whether they store ingested lipids as a buffer against possible future starvation. We fed wolf spiders (Pardosa prativaga ) prey of different lipid:protein compositions and measured the metabolic rate of spiders using closed respirometry during feeding and fasting. After a 16-day feeding period, spider lipid:protein composition was significantly affected by the lipid:protein composition of their prey. Feeding caused a large and fast increase in metabolism. The cost of feeding and digestion was estimated to average 21% of the ingested energy irrespective of diet. We found no difference in basal metabolic rate between dietary treatments. During starvation V˙O2 and V˙CO2 decreased gradually, and the larger lipid stores in spiders fed lipid-rich prey appeared to extend survival of these spiders under starvation compared to spiders fed protein-rich prey. The results show that these spiders do not adjust metabolism in order to maintain a constant body composition when prey nutrient composition varies. Instead, lipids are stored efficiently and help to prepare the spiders for the long periods of food deprivation that may occur as a consequence of their opportunistic feeding strategy.
Journal: Journal of Insect Physiology - Volume 56, Issue 9, September 2010, Pages 1095–1100