Captured a great video of the abdomen pulsing & opening for air exchange (below)...these pictures capture a moment...
I added a link to a YouTube video of insect at rest, documenting respiration--abdomen "pulsing" & separating to allow air exchange.
(see "more fields" below.)
San Diego County, California, US
Found near a pond
The Flame Skimmer or Firecracker Skimmer (Libellula saturata) is a common dragonfly of the family Libellulidae, native to western North America.