Density And Biomass Of Meiofauna In The Taiwan Strait And Its Adjacent Waters

Meiofauna are species-richness and numerous in the ocean.They are the food of fish,shrimp and crab,and they play an important role in the marine food chain. Miofauna research is an important component of marine biological survey.The study of meiofauna is significant to understand the marine benthic ecosystem structure and function.The studies of meiofauna in the Taiwan Strait and its adjacent waters were carried out in July(Summer) and December(Winter),2006 and in April(Spring) and October(Autumn),2007.In this paper,we discussed density,biomass,community structure and biodiversity of meiofauna.The main results are as follows:The average water deepth was 41 meters in stations.The sediment tpyes of the sampling stations mainly belonged to silt-clay(TY) and sand-silt(ST).A total of 15 groups of meiofauna were identified in the Taiwan Strait and its adjacent waters.They were Nematoda,Copepoda,Polychaeta,Ostracoda,Bivalvia,Kinorhyncha, Tanaidacea,Gastropoda,Amphipoda,Halacaroidea,Nauplius,Coelenterata, Cumacea and Others.Freeing living marine Nematodes and Copepodes were the two dominant groups.The average density of meiofauna in four cruises were 311.94±18.52 ind / (10cm~2).The dengsity in four cruises were:331.97±234.85 ind /(10cm~2) in summer, 318.32±186.55ind /(10cm~2) in autumn,311.82±313.20 ind /(10cm~2) in spring,and 286.80±239.41ind /(10cm~2) in winter.The average biomass in the study were 345.02±70.16μg·dwt/10cm~2.Spring:280.84±263.62μg·dwt/10cm~2.Summer: 443.70±412.04μg·dwt/10cm~2.Autumn:315.18±183.45μg·dwt/10cm~2.Winter: 340.36±224.15μg·dwt/10cm~2.In terms of horizontal distribution,stations near the coast had higher density and biomss of meiofauna.The highest density was 867.75±290.78 ind /(10cm~2) in ZD-XM585 station.And the lowest density was 66.73±22.86 ind /(10cm~2) in ZD-XM657 station.In terms of vertical distribution,60.28%of total meiofauna was found in the surface sediments of 0-2cm layer.There were 27.54%of total meiofauna in 2-5cm layer.The average density of marine nematodes in four cruises were 266.15±10.62 ind /(10cm~2),and the highest density was 799.15±118.20 ind /(10cm~2) in ZD-XM585 station.Spring:278.44±281.13 ind /(10cm~2);Summer:269.51±226.76 ind /(10cm~2);Autumn:263.53±215.55 ind /(10cm~2);Winter:253.14±230.62 ind / (10cm~2).In terms of vertical distribution,62.57%of marine nematode were found in the surface sediments of 0-2cm layer.There were 25.01%of marine nematode in 2-5cm layer.12.41%of marine nematode were found in 0-5cm layer.A total of 52 species or taxa of free living marine nematodes,belonging to 32 genera,15 families and 3 orders,were identified at JCDH492,ZD-MJK532,ZD-MJK551,ZD-XM626 and ZD-MJK560 stations in autumn cruise.The dominant genera of marine nematodes were Dorylaim o psis,Xyala,Sabatieria and Xyala.