Coeliccia sasamotoi is a rather large-sized Coeliccia species, described based from specimens collected in 2004-2005 in central Vietnam (Ha Tinh Province) and central east Laos.
In 2011, I bumped into this species much further north, in the Hoa Binh Province, northern Vietnam (70 km east of Hanoi).
The male is a beautiful black and sky blue damselfly. The dorsum of synthorax bears 2 pairs of markings as follow: one pair of large patches, each one bicoloured (sky blue along the dorsal carina, whitish exteriorly), covering almost half the lower part of mesepisternum, and a much smaller upper pair.
Sides of synthorax with large bluish markings. The abdomen is largely black dorsally, including the last segments, contrasting with the light coloured anal appendages.
Caudal appendages white-yellowish, contrasting with the wholly black last segments.
- Dorsal view
The female is stouter than the male. The mesepisternum bears 2 pairs of yellow stripes, the upper one roughly half the size of the lower one.
Sides of synthorax and prothorax mostly yellow. Posterior pronotal lobe black with a broad raised process.
Abdomen black with yellow markings.
The site where I took almost all of those pictures (in Hoa Binh Province) is situated along a swift, rocky stream in secondary forest (ca 500 a.s.l.). I spotted males resting above small shaded pools in the beds, often in the company of C. acco, C. onoi.