Species: Epeorus khayengensis  Braasch & Boonsoong, 2010
Phylum: Arthropoda
Class: Insecta
  Order: Ephemeroptera
   Family: Heptageniidae
    Genus: Epeorus
Collection specimen
 - Mature male larva: Zoological Museum, Kasetsart University, Bangkok, Thailand
     - 7 larvae: Zoological Museum, Kasetsart University, Bangkok, Thailand, 1 male Larva and 1 female Larva: collection Dietrich Braasch, Potsdam, Germany

 The larva of E. khayengensis can be distinguished from that of other congeners by abdominal terga 2–9 without long acute median spine on posterior margin, but bearing long hair-like setae (Boonsoong and Braasch, 2013).


Larva of Epeorus khayengensis (Source: Braasch and Boonsoong, 2010)

Habitat: The larva of E. khayengensis inhabits tropical headwater streams approximately 210 m in alt. The streams range between 6–7 m in width and 10–11 cm in depth. The water temperature ranges between 22–25°C, pH between 6.35–7.15, total dissolved solids are between 27–34 mg/L, and conductivity is between 41–53 µS/cm. The larvae are found in eroded areas of streams where moderately flowing over cobble and sandy bottom.

 - Huai Khayeng stream (Thong Pha Phum district, Kanchanaburi province

Work cited:
 - Boonsoong, B. and Braasch, D. 2013. Heptageniidae (Insecta, Ephemeroptera) of Thailand. ZooKeys 272: 61–93.
 - Braasch, D. and Boonsoong, B. 2010. A contribution to the Heptageniidae (Insecta, Ephemeroptera) of Thailand and Malaysia. Zootaxa 2610: 1–26.

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