The meiofauna composition and trophic groups of the nematode communities have been studied at a sandy intertidal zone in Sishili Bay along the Yantai coast(Yellow Sea,China).Nematoda was dominant among the 11 groups o...The meiofauna composition and trophic groups of the nematode communities have been studied at a sandy intertidal zone in Sishili Bay along the Yantai coast(Yellow Sea,China).Nematoda was dominant among the 11 groups of meiofauna.The meiofaunal densities were low,ranging between 111±47 and 542±131 ind./10 cm^(2).Results obtained from the correlation analysis made it possible to determine several factors that influence species composition and distribution.Generally,sediment granulometry significantly affected the communities.The highest abundance was found in fine-grained sediments(318.77±126 ind./10 cm^(2))com-pared to coarse-grained sediments(175±82 ind./10 cm2).Nematodes were predominant in all studied sites.A total of 70 species be-longing to 52 genera and 18 families were identified in the study area.There was a significant difference in nematode abundance(ANOVA,F=2.38,P<0.05)between the three sites.Nematode communities were characterized by a high level of species diversity in sediments composed mainly of very-fine sands(>63μm),with dominant species belonging to the genus Bathylaimus,Ptycho-laimellus,Spirinia,and Sabatieria.The trophic groups were dominated by non-selective deposit feeders(40.7%)and epistrate feed-ers(41.29%).In contrast,the species composition in medium grain sands was characterized by a low species diversity index and a high Simpson dominance index.Nematode communities showed similar dominant species compositions belonging to a single genus Bathylaimus,Enoplolaimus,and Oncholaimus,and in terms of trophic structure-representatives of deposit feeders(46.15%),preda-tors,and omnivores(64.71%)prevailed.The divergence of meiofaunal community structures can be explained by abiotic factors such as sediment grain size,salinity,and organic carbon content.Specifically,sediment particle size can explain the diversity of nematodes at the level of in abundance,diversity indices,and trophic structure.The highest nematode density and diversity coincided with the highest percentage of very fine sands.展开更多
文摘The meiofauna composition and trophic groups of the nematode communities have been studied at a sandy intertidal zone in Sishili Bay along the Yantai coast(Yellow Sea,China).Nematoda was dominant among the 11 groups of meiofauna.The meiofaunal densities were low,ranging between 111±47 and 542±131 ind./10 cm^(2).Results obtained from the correlation analysis made it possible to determine several factors that influence species composition and distribution.Generally,sediment granulometry significantly affected the communities.The highest abundance was found in fine-grained sediments(318.77±126 ind./10 cm^(2))com-pared to coarse-grained sediments(175±82 ind./10 cm2).Nematodes were predominant in all studied sites.A total of 70 species be-longing to 52 genera and 18 families were identified in the study area.There was a significant difference in nematode abundance(ANOVA,F=2.38,P<0.05)between the three sites.Nematode communities were characterized by a high level of species diversity in sediments composed mainly of very-fine sands(>63μm),with dominant species belonging to the genus Bathylaimus,Ptycho-laimellus,Spirinia,and Sabatieria.The trophic groups were dominated by non-selective deposit feeders(40.7%)and epistrate feed-ers(41.29%).In contrast,the species composition in medium grain sands was characterized by a low species diversity index and a high Simpson dominance index.Nematode communities showed similar dominant species compositions belonging to a single genus Bathylaimus,Enoplolaimus,and Oncholaimus,and in terms of trophic structure-representatives of deposit feeders(46.15%),preda-tors,and omnivores(64.71%)prevailed.The divergence of meiofaunal community structures can be explained by abiotic factors such as sediment grain size,salinity,and organic carbon content.Specifically,sediment particle size can explain the diversity of nematodes at the level of in abundance,diversity indices,and trophic structure.The highest nematode density and diversity coincided with the highest percentage of very fine sands.
