Freshwater Macroinvertebrates in Hong Kong

Epeorus sagittatus

General appearance
Body color yellowish brown with some greyish and brownish markings; size large up to 14mm long (excluding antennae & cerci)
Cerci slightly longer than body length; medium filament greatly reduced to give a 2-tailed impression

Head
Head flattened in oval shape; antennae short slightly less than head width
The details for mouthparts illustrated in the following pictures

Thorax
The details for legs illustrated in the following pictures

Abdomen
Gills I - VII well tracheated with fibrilliform portion
Change of spines on posterior margin from minute on tergum I to prominent triangular shaped on tergum X
Long fine setae located along midline of abdomen

Legs

Its mouthparts of labrum, mandibles, maxillae and labium are illustrated as follow (hypopharynx is excluded). Mouthpart fullview

Labrum

Maxillae

Mandibles

Labium

Distribution:
In Hong Kong, specimens are recorded from Upper Ha Wun Yiu (Tai Po), Tai Po Kau Forest Stream, Shing Mun, Lam Tsuen River, Ho Chung (Sai Chung) and Shek Mun Kap (Lantau Island).

Habitat: Larvae are found in fast flowing current in upland streams.