Water balance and osmoregulation in Stips stali, a nocturnal tenebrionid beetle from the Namib Desert

摘要: Abstract Dehydration (6 days at 26°C) of the Namib tenebrionid beetle, Stips stali (Haag), resulted in weight loss (approx 7%), a drop total body water, and substantial decline haemolymph volume (33%). All these values returned to normal when access water was permitted (day 6–day 8). Haemolymph osmolality, sodium, potassium chloride concentrations increased during dehydration decreased rehydration, but despite marked changes haemolymph, parameters were subject osmoregulatory control. However, although sodium had end rehydration period, level remained lower than normal. While protein as expected from haemolymph-concentration -dilution, lipid levels constant throughout dehydration. Over short-term, therefore, does not or cannot mobilize its lipid, metabolic input via this avenue appears be negligible. Drinking (when fog is available) probably contributes largely uptake, together with efficient conservation, must serve effectively maintain balance insects.