ИСТИНА

Prominent seasonality were found both in community’s structure and in life cycles of nematodes on mangrove seventIMCO oral presentations T2 39 intertidal flat. Seasonal changes in nematodes community were studied on the station situated in the mangrove forest of Kandelia candel in the Red River delta, North Vietnam. Quantitative samples were collected seasonally in muddy sediments between mangrove trees (in October, January, April and August). Totally 69 species from 44 genera and 21 family were identified in samples. Total nematodes abundance was rather stable with no prominent pikes, the mean values fluctuate around 600 ind./10 cm2, seasonal differences were not significant. Species composition is stable during the year and changes appear in relative proportion within the group of dominated species. Two seasonal aspects in community structure described: in autumn and winter Sabatieria + Terschellingia are most common, while Ptycholaimellus + Metachromadoroides predominate in spring and in summer. Seasonality in community composition reflects mainly combination of different life cycles of most abundant species. Age structure was described for 11 most common species by seasons. Seasonal changes in abundance found for all the species in different extent, five species reveal strong seasonal changes with maximum in different seasons. Life cycles varied from rather smooth with continuous reproduction along the year to prominent seasonality in reproduction.