Water balance and osmoregulation in Stenocara gracilipes, a wax-blooming tenebrionid beetle from the Namib Desert

摘要: Abstract Dehydration (10 days at 27°C) of the Namib tenebrionid Stenocara gracilipes resulted in a rapid weight loss (17.5%), and substantial decline haemolymph volume (72%). Although lipid content decreased significantly, metabolic water production was insufficient to maintain total body (TBW). Rehydration (no food) increases volume, (sub-normal), TBW normality. Haemolymph osmolality, sodium, potassium, chloride, amino acids, sugars (trehalose glucose), were all subject osmoregulatory control during both dehydration rehydration. Major osmolar effectors this species are with most contribution regulation osmolality coming from changes levels these constituents. Changes acid not result interchange soluble protein (the possibility exists extended rehydration, however). Despite faecal losses sodium being low (8.2% that removed dehydration), concentrations do return normal Chloride increase supra-normally when access is allowed, remain elevated throughout rehydration period. potassium greatly exceeded amount (by approximately 1.8 times), strongly regulated S. demonstrates an exquisite capacity regulate under conditions acute water-shortage -abundance. Together efficient economy (drinking fog-water available, superb conservation mechanism form wax-bloom production), must serve contribute long-term survival otherwise harsh abode.