Breathe softly, beetle: Continuous gas exchange, water loss and the role of the subelytral space in the tenebrionid beetle, Eleodes obscura

摘要: Abstract Flightless, diurnal tenebrionid beetles are commonly found in deserts. They possess a curious morphological adaptation, the subelytral cavity (an air space beneath fused elytra) function of which is not completely understood. In beetle Eleodes obscura, we measured abdominal movements within cavity, and activity pygidial cleft (which seals or unseals cavity), simultaneously with total CO2 release rate water loss rate. First, that E. obscura has lowest cuticular permeability flow-through respirometry an insect (0.90 μg H2O cm−2 Torr−1 h−1). Second, it does exhibit discontinuous gas exchange cycle. Third, describe temporal coupling between exchange, loss, volume, capacity to gases its surroundings as indicated by state. Fourth, suggest possible mechanisms may reduce respiratory rates obscura. Finally, cannot discontinuously because constraint (small tracheal spiracular conductance). This “conductance hypothesis” help explain otherwise puzzling phylogenetic patterns continuous vs. observed tracheate arthropods.