Annotated checklist of freshwater molluscs from the largest freshwater lake in Southeast Asia Author Ng, Ting Hui Lee Kong Chian Natural History Museum, Faculty of Science, National University of Singapore, 2 Conservatory Drive, 117377, Singapore https://orcid.org/0000-0002-5123-0039 Author Jeratthitikul, Ekgachai Animal Systematics and Molecular Ecology Laboratory, Department of Biology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand https://orcid.org/0000-0002-3477-9548 Author Sutcharit, Chirasak Animal Systematics Research Unit, Department of Biology, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Pathumwan, Bangkok 10330, Thailand Author Chhuoy, Samol Inland Fisheries Research and Development Institute (IFReDI), Fisheries Administration, No. 86, Norodom Blvd., PO Box 582, Phnom Penh, Cambodia & Wonders of the Mekong Project, c / o IFReDI, No. 86, Norodom Blvd., PO Box 582, Phnom Penh, Cambodia Author Pin, Kakada Wonders of the Mekong Project, c / o IFReDI, No. 86, Norodom Blvd., PO Box 582, Phnom Penh, Cambodia Author Pholyotha, Arthit Animal Systematics Research Unit, Department of Biology, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Pathumwan, Bangkok 10330, Thailand https://orcid.org/0000-0001-6677-1164 Author Siriwut, Warut Animal Systematics and Molecular Ecology Laboratory, Department of Biology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand Author Srisonchai, Ruttapon Department of Biology, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand Author Hogan, Zeb S. Wonders of the Mekong Project, c / o IFReDI, No. 86, Norodom Blvd., PO Box 582, Phnom Penh, Cambodia & Department of Biology, University of Nevada, 1664 N. Virginia Street, Reno, NV 89557, USA Author Ngor, Peng Bun Inland Fisheries Research and Development Institute (IFReDI), Fisheries Administration, No. 86, Norodom Blvd., PO Box 582, Phnom Penh, Cambodia & Wonders of the Mekong Project, c / o IFReDI, No. 86, Norodom Blvd., PO Box 582, Phnom Penh, Cambodia https://orcid.org/0000-0002-3659-6577 pengbun.ngor@gmail.com text ZooKeys 2020 958 107 141 http://dx.doi.org/10.3897/zookeys.958.53865 journal article http://dx.doi.org/10.3897/zookeys.958.53865 1313-2970-958-107 AB196008154249D4B23E1892D2191C18 377C3EF18E8951FD9599616E45E03C94 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.