Scientific Name: Onychargia atrocyana
Common Name: Shorttail, Marsh Dancer
Onychargia atrocyana is a very widely distributed damselfly species. It is distributed throughout South-East Asia, India and China. In Singapore, this species is uncommon and found mainly in densely vegetated and leafy-bottomed pools, marshes in swampy forested areas. I have personally come across this species at Chestnut avenue biking trail and the densely forested area in Mandai.
As this species breeds in leafy pools and marshes, it is often seen mating in tandem in these habitats.
Both males and females are stoutly built with short abdomen and long legs. Older males are blackish with hues of purple on the thorax. Young males have thick light yellowish stripes on the sides of the thorax.
Females thorax are also dark with two yellowish stripes on the dorsum. The abdomen is dark on the dorsal side and yellowish on the ventral side.