Sinomytilus harmandi (Rochebrune, 1882) Fig. 2C

Dreissena harmandi Rochebrune, 1882: 102. Type locality: "Lac de Rhom-Penh, Mekong".

Sinomytilus harmandi: Brandt 1974: 307, pl. 26, fig. 69; Morton and Dinesen 2010: 57-72.

Material examined.

ZRC.MOL.015657, ZRC.MOL.015658, ZRC.MOL.015659, ZRC.MOL.015667, ZRC.MOL.015668.

Distribution and habitat.

Similar to that of Limnoperna fortunei .

Remarks.

Sinomytilus harmandi appears to be limited in range to the Lower Mekong River basin, and it may have previously been mistaken for Limnoperna fortunei, resulting in a lack of historical records (Morton and Dinesen 2010). Our finding that Sinomytilus harmandi often co-occurs with Limnoperna fortunei, but in much lower densities, may further account for the former being overlooked in the literature. Sinomytilus harmandi may be distinguished from Limnoperna fortunei by the presence of an interior shell septum.