Introduction: Little is known about the ecology or behaviour of the Long Slim (Aciagrion (Mombagrion) heterostictum). It is believed to live in swamps. The pterostigma of the forewing is 'tattooed and spotted'.
Distribution: Only 1 male has been recorded in Namibia near Katima Mulilo. Possibly more widespread along the Zambezi River.
Colouration: Pale green thorax with underdeveloped stripes.
Breeding: Larva leaves the water after a short time due to the possibility of starvation or drowning.
Flight season: December to March.
Max size: Long Slims have the longest abdomen known in the genus of 39mm.