obsolete spiracle true UBERON:0001006 MAT:0000208 spiracle of open tracheal system spiracular gland Wikipedia:Spiracle This class was obsoleted as it grouped together disparate classes. For the fish structure, see UBERON:0010019. The arthropod structure will presumably be added to the arthropod anatomy OBSOLETE: The mostly slit-like opening on the body surface through which air is taken into the respiratory system. open tracheal system spiracle EFO:0000936 MIAA:0000208 spiracle (sensu Vertebrata)