Water balance and osmoregulation in Physadesmia globosa, a diurnal tenebrionid beetle from the Namib desert

摘要: Abstract Dehydration (10 days at 26°C) of the Namib tenebrionid beetle Physadesmia globosa resulted in rapid weight loss (approx. 19%), and a substantial decline haemolymph volume (61%). Although lipid content decreased significantly during this period, metabolic water production was insufficient to maintain total body water. Rehydration (no food) increases (sub-normal), normality. Haemolymph osmolality, sodium, potassium chloride concentrations increased dehydration, but despite marked decrease haemolymph, changes these parameters were subject osmoregulatory control. Protein dehydration rehydration. Rapid rehydration (1 h) is well-controlled: while dramatically, strongly regulated. However, extended (over 4 days) appears not be as well managed by Physadesmia, with osmolality sodium decreasing no significant change from immediate post-rehydration values. The concentrations, however, appeared under stricter control period. Drinking (when fog available) probably contributes largely input together efficient conservation must serve effectively long-term balance insects.