This paper showed result of the studying composition and abundance of meiofaunal communities from Cung Hau estuary and Ham Luong estuary, with special focus on the nematode communities. The results of this study will illustrate the overall patterns in the species composition, density and diversity of meiofaunal communities in two estuaries Ham Luong and Cung Hau of Me Kong Delta in the Southern of Vietnam. | TẠP CHÍ SINH HỌC, 2012, 34(3SE): 1-12 THE NEMATODE COMMUNITY DISTRIBUTION IN TWO ESTUARIES OF THE ME KONG DELTA: CUNG HAU AND HAM LUONG, SOUTH VIETNAM Nguyen Van Sinh1*, Ngo Xuan Quang1, Ann Vanreusel2, Nicole Smol2 1 Institute of Tropical Biology, VAST, (*)nguyensinhhcm@ 2 Ghent University, Krijgslaan 281, S8, B-9000 Ghent, Belgium ABSTRACT: The highest numbers of nematodes with a percentage ranging from in Cung Hau to 77% in Ham Luong estuaries. There were 92 genera (71 genera in Ham Luong and 62 genera in Cung Hau) of nematodes recorded in both estuaries. The mean nematode densities varied between 90 ± 31 1524 ± 269 cm² and 105 ± 79 - 1120 ± 534 cm² in Ham Luong and Cung Hau estuary, respectively. The nematode communities were mainly composed of Dichromadora, Daptonema, Oncholaimellus, Syringolaimus, Tripyloides, Parodontophora, Theristus and Halalaimus belonging to several dominant families, such as, Oncholaimidae, Xyalidae, Chromadoridae, Oxystominidae, Axonolaimidae and Sphaerolaimidae. In both estuaries, nematode density decreased from inland towards the mouth before they increased again at the mouth stations. Keywords: Biodiversity, estuary, meiofauna, nematode, Me Kong delta. INTRODUCTION The Me Kong river is one of the longest rivers in the world, beginning from Tibetan plateau and running through six countries into the Indo-China peninsula. The Me Kong river carries a lot of alluvium from upriver to the lower basin of the Me Kong river delta in South Vietnam. At the lower basin of the Me Kong delta, the habitat is characterized by mudflats and mangrove forest along the mouth of estuaries. Ham Luong and Cung Hau estuaries are two branches of the Me Kong river in the southern Vietnam. They are the fourth and sixth estuary respectively from the first Cua Tieu estuary. Estuary is also an important habitat for a large number and variety of organisms Day et al. (1989) [8]. The species composition and structure of the meiofaunal
