General appearance
Body size small medium up to 5 mm long (excluding antennae & cerci)
Body yellowish brown with diffuse black markings

Abdomen
Abdominal terga extend around to venter of abdomen where gills arisen underneath abdomen
Gills II - VI slender in double lamellae; gill VII single lamella
Postero-lateral projections (spines) progressively increased in size on abdominal segments VII - IX

 

Distribution:
In Hong Kong, specimens are recorded in Shing Mun, Chuen Lung, Sha Lo Tung, Lam Tsuen River, Tai Po Kau Forest Stream, Tai Shui Hang & Mui Tsz Lam (Ma On Shan), Ho Chung (Sai Kung), Wang Shan Keuk (Pat Sin Leng), Pui O, Sam A Shui, Shek Mun Kap & Wang Lung Hang (Lantau Island), widespread in Hong Kong streams where it lives in fast flowing water.