Three species in genus Sabatieria and one in genus Cervonema from the East China Sea were recorded. S. breviseta is characterized by uniformly punctuated coarse dots, large amphids of 5.5 turns (♂) and prominent gube...Three species in genus Sabatieria and one in genus Cervonema from the East China Sea were recorded. S. breviseta is characterized by uniformly punctuated coarse dots, large amphids of 5.5 turns (♂) and prominent gubernaculum median piece. The characters of S. breviseta agree quite well with the European original descriptions and only differ in the male amphid turns (5.5 vs. 4.0 turns) and unmodified preanal supplements (5-7 vs. 6). S. pulchra can be recognized by amphid 2.75 turns, irregularly arranged lateral dots, and the first three supplements anterior to the anus, which are more widely spaced than the following ones. The excretory system of S. breviseta and S. pulchra shows sexual dimorphism. S. celtica is defined by amphids 2.00-2.25 turns, weakly developed pharyngeal bulb, curved apophyses and 12-13 conspicuous supplements. C. deltensis is characterized by amphids 4.75 turns, ovate pharyngeal posterior bulb, sperm dimorphism, 7 thin preanal supplements, and long tail cylindrical portion (50%-53% of tail length). All the three Sabatieria species are for the first time recorded in Chinese waters. C. deltensis was originally isolated from the Bohai Sea and Yellow Sea and newly recorded in the East China Sea.展开更多
Mangroves are unique in their biodiversity,but studies on their meiobenthic biodiversity in China are scarce.Despite the importance of mangroves,little work has been done on the classification of nematodes in mangrove...Mangroves are unique in their biodiversity,but studies on their meiobenthic biodiversity in China are scarce.Despite the importance of mangroves,little work has been done on the classification of nematodes in mangrove wetlands.Fujian Province is the most northern point of China’s natural mangrove distribution,and it is also one of the provinces with the earliest constructed mangrove forest.In this paper,two new free-living marine nematode species of Desmodoridae from the Xiamen mangrove wetlands in China are described.Metachromadora xiamenensis sp.nov.is characterized by a cylindrical body,and smooth head capsule set off from the rest of the body.The cuticle is finely annulated and thickened at the midbody.Lateral ridges run from the posterior end of the pharynx to the middle of the tail.The amphid foveae is loop shaped and opens at the top with a double contour amphidial,pharynx with bipartite cuticularized internal cavity.There are 18 tubular precloacal supplements and tail with three small protuberances.Molgolaimus euryformis sp.nov.is characterized by a relatively short and plump body with finely annulated cuticle,which is particularly obvious in the tail.The head is small and wide with intensive striates.The inner and outer labial sensilla are indistinct with short spicules and ventral apophysis,a gubernaculum with a block-shaped hook,a swollen conical-cylindrical tail and an absence of precloacal supplements.展开更多
A new free-living marine nematode species of the genus Rhinema belonging to the family Monoposthiidae was collected from marine sediments in the Qiongzhou Strait of the South China Sea,and it is described here as Rhin...A new free-living marine nematode species of the genus Rhinema belonging to the family Monoposthiidae was collected from marine sediments in the Qiongzhou Strait of the South China Sea,and it is described here as Rhinema longispicula sp.nov.The new species is characterized by coarsely annulated cuticle with 12 longitudinal ridges(alae)marked as reversed V-shaped.The first and second annuli broader and form a kind of a cephalic capsule.The amphideal fovea circular,situated in the middle of the broad second annulus,not surrounded by dense annulations.Buccal cavity cylindrical with a large dorsal tooth.Pharynx with a prominent anterior pharyngeal bulb and an elongated terminal bulb.Elongate spicules strongly curved,with cephalated proximal end and pointed distal end.Gubernaculum boat-shaped,without apophysis.A long and blunt precloacal seta present.Female with two opposed,outstretched ovaries.展开更多
One new species of free-living marine nematode of the genus Curvolaimus, Curvolaimus filiformis sp. nov. from the Huanghai Sea isdescribed and illustrated. This new species is characterized by the buccal cavity teeth,...One new species of free-living marine nematode of the genus Curvolaimus, Curvolaimus filiformis sp. nov. from the Huanghai Sea isdescribed and illustrated. This new species is characterized by the buccal cavity teeth, large amphids and two ventral seta at the conicalpart of tail. Meanwhile, two new records of genus Halalaimus, Halalaimus longicaudatus and H. isaitshikovi are first reported in China.Types are deposited in the College of Marine Life Sciences, Ocean University of China.展开更多
One new species of free-living marine nematodes Cephalanticoma filicaudata sp. nov. from the Huanghai Sea, China is described and illustrated. Cephalanticoma filicaudata sp. nov. is characterized by well developed cep...One new species of free-living marine nematodes Cephalanticoma filicaudata sp. nov. from the Huanghai Sea, China is described and illustrated. Cephalanticoma filicaudata sp. nov. is characterized by well developed cephalic capsule, three teeth at the anterior of oesophagus, excretory pore opens posterior to cervical setae, only two cervical setae per file, body length longer than 5 200 μm, tail long and no ventral-lateral seta between the supplement and the cloacal opening. Types are deposited in the College of Marine Life Sciences, Ocean University of China.展开更多
Two new species of free-living marine nematode from mangrove habitats in Xiamen Bay are identified.Anoplostoma tumidum sp.nov.is characterized by relatively short outer labial setae(0.86–1.00 h.d.),long tail(c 7.2–8...Two new species of free-living marine nematode from mangrove habitats in Xiamen Bay are identified.Anoplostoma tumidum sp.nov.is characterized by relatively short outer labial setae(0.86–1.00 h.d.),long tail(c 7.2–8.9,c' 8.3–10.5),an instinct swollen distal portion of slender spicule(Sc 94–101 μm),and well developed copulatory bursae without bursal papillae.A.tumidum sp.nov.differs from all valid species of genus Anoplostoma in copulatory apparatus of males with a distinct swollen distal portion of spicule,and a relatively obvious constriction of head.A.paraviviparum sp.nov.is characterized by relatively long outer labial setae(1.11–1.22 h.d.),and tail(c 6.6–8.5,c' 8.6–10.2);elongated spicules with distinct knob-like proximal and pointed distal ends(Sc 46–69 μm);distinct strip-like gubernaculum(length with 11–15μm);well developed copulatory bursae with precloacal papillae and post-cloacal papillae;and a distinct constriction of head.A.paraviviparum sp.nov.is similar to A.viviparum Bastian,1865,but differs in the reproductive mode of female and the constriction of head.展开更多
One new species of free-living marine nematode Cephalanticoma brevicaudata sp. nov. from the South China Sea is described. Cephalanticoma brevicaudata sp. nov. is characterized by spindle body with relatively short ta...One new species of free-living marine nematode Cephalanticoma brevicaudata sp. nov. from the South China Sea is described. Cephalanticoma brevicaudata sp. nov. is characterized by spindle body with relatively short tail; head with cephalic capsule; three teeth at anterior of pharynx; excretory pore opens posterior to cervical setae; three cervical setae per file; spicules arcuate, cephalate and ventrally bent proximally, and blunt distally, 1.8 a.b.d. long, without ventral ala; gubernaculun slender, simple rod, without apophyses; tubular supplement 34 μm long, 2.3 a.b.d. in front of cloaca.展开更多
A quantitative study on the community structure and biodiversity of free-living marine nematodes and their relationship with environmental factors in the northern South China Sea were carried out based on the samples ...A quantitative study on the community structure and biodiversity of free-living marine nematodes and their relationship with environmental factors in the northern South China Sea were carried out based on the samples collected at five stations in the deep sea(from 313 to 1 600 m) and one station in shallow waters(87 m) during the cruise in September, 2010. Results showed that the abundance of marine nematodes ranged from 224 to 1 996 ind./(10 cm2). A total of 69 free-living marine nematode genera, belonging to 26 families and three orders, were identified. The most dominant genera were Sabatieria, Linhystera, Aegialoalaimus and Daptonema according to SIMPER analysis. Results of CLUSTER analysis revealed four types of marine nematode community(or station groups) in the sampling area. In terms of trophic structure, non-selective deposit feeders(1B) and selective deposit feeders(1A) were the dominant trophic types with highest genera numbers and abundances, which implied that organic detritus was the main food source of marine nematodes in the northern South China Sea.The percentage of male nematode was low, ranging from 2.22% to 17.81%, while those of juvenile individuals ranged from 36.99% to 82.09%. For genera level diversity of marine nematodes, Shannon-Wiener diversity indices(H') ranged from 3.76 to 4.57 and had highly significant negative correlation with water depth. In general, diversity indices H' at the five stations in deep sea(over 200 m) were lower than that at the station in shallow waters(87 m).BIOENV analysis showed that the most important environmental factor controlling marine nematode communities was water depth.展开更多
Biodiversity patterns of free-living marine nematodes were studied using specific,taxonomic and phylogenetic diversity measures in the southern Yellow Sea,China.The results showed that the average of Shannon-Wiener di...Biodiversity patterns of free-living marine nematodes were studied using specific,taxonomic and phylogenetic diversity measures in the southern Yellow Sea,China.The results showed that the average of Shannon-Wiener diversity index(H′) in the study area was 3.17.The higher values were distributed in the east part of Shandong coastal waters and north part of Jiangsu coastal waters,while the lower values were distributed in the southern Yellow Sea Cold Water Mass(YSCWM).The average of taxonomic diversity(Δ) was 62.09 in the study region.The higher values were distributed in the transitional areas between the coastal areas and the southern YSCWM,while the lower values were distributed near the north part of Jiangsu coastal waters and the YSCWM.Results of correlation analysis of species diversity and taxonomic diversity showed that some of the two kinds of diversity index were independent,which suggested that combining the two kinds of diversity indices can reflect the ecological characteristics better.A test for 95% probability funnels of average taxonomic distinctness and variation in taxonomic distinctness suggested that Station 8794(in the YSCWM) was outside of the 95% probability funnels,which may be due to the environmental stress.Results of correlation analysis between marine nematodes biodiversity and environmental variables showed that the sediment characteristics(Md? and Silt-clay fraction) and phaeophorbide a(Pha-a) were the most important factors to determine the biodiversity patterns of marine nematodes.展开更多
Nematodes are small multicellular, thread-like organisms, inhabiting almost all conceivable environments;among these, some 25 % are free-living marine forms with a population density of(1–12) 9 106 inds m-2in seabed ...Nematodes are small multicellular, thread-like organisms, inhabiting almost all conceivable environments;among these, some 25 % are free-living marine forms with a population density of(1–12) 9 106 inds m-2in seabed sediment, reaching maximum values in muddy estuaries and salt marshes. A large quantity of carbon from the salt marsh plants enters the ecosystem via the detritus pathway,in which nematodes play an important role through their feeding and bioturbation activities. Vegetation influences the sedimentary environment and modifies the distribution pattern of nematode communities in coastal wetlands.Nematodes are coupled closely with bacteria/detritus in microbial food webs, stimulating bacterial growth and subsequent nutrient remineralization; they provide food sources for higher trophic levels and serve as a linkagebetween micro- and macro-fauna. Furthermore, nematodes have a potential to provide proxies that can be used in diagnosing environmental quality. In China, only a limited number of nematode data sets are available for the coastal wetlands across several different climatic zones. It is necessary to carry out additional investigations into the biology and ecology of nematodes in order to delineate their ecological functioning in coastal wetlands. On such a basis,the contribution made by nematodes to material cycling and the ecological functioning in coastal wetlands can be quantified. The assessment of their biological diversity should be a focus, which is fundamental in the study of wetland ecosystem dynamic mechanisms. In addition to laboratory and mesocosm experiments, mathematical models should be established to predict the responses of ecosystem to the environmental disturbance. Finally, it is necessary to improve the techniques for nematode analysis,to enhance the efficiency of data acquisition.展开更多
Free living marine nematodes were sampled from two sandy beaches in Dalian City,in December of 2015,and April,July,and October of 2016.The spatial and seasonal variations of marine nematode species diversity(based on ...Free living marine nematodes were sampled from two sandy beaches in Dalian City,in December of 2015,and April,July,and October of 2016.The spatial and seasonal variations of marine nematode species diversity(based on species abundance dataset)and functional diversity(based on functional traits dataset:feeding types and life history strategies)were investigated to understand the environmental drivers and how they respond to specific environmental variations.Sediment granularity was revealed to be the main environmental factor causing spatial differences in nematode diversity indices between the two beaches.Species diversity indices,namely species number,Margalef index,Shannon-Wiener diversity index(H’),were higher in fine-grained sediments,while the functional diversity indices,including functional evenness,functional dispersion,and Rao’s quadratic entropy index(RaoQ),were higher in coarse-grained sediments.Nematode species diversity indices also fluctuated with seasonal variations of temperature,dissolved oxygen,pH,salinity,and sediment chlorophyll-a within the study beaches.However,functional diversity indices did not show significant seasonal variations and exhibited weak correlation with the studied environmental variables.Overall,the functional diversity indices were negatively correlated with the species diversity indices,suggesting an inconsistent response to environmental changes.A decrease in nematode species diversity in coarse sands,accompanied by an increase in functional diversity,can be regarded as an early warning signal of environment disturbance.If more biological traits are involved in calculating functional diversity indices,it will be helpful for the future study of the internal connections of species diversity and functional diversity.展开更多
Marine free-living nematodes were investigated at 13 sampling stations divided into three transects in the northern Taiwan Strait in February 1998. One hundred species of marine nematodes belonging to 91 Genera 28 Fam...Marine free-living nematodes were investigated at 13 sampling stations divided into three transects in the northern Taiwan Strait in February 1998. One hundred species of marine nematodes belonging to 91 Genera 28 Families 3 Orders were identified and were first recorded in the northern Taiwan Strait. The dominant species were Vasostoma sp., Sabatieria sp. 1, Linhystera sp. 1, Spilophorella sp., Daptonema sp., Halalaimus sp. and Dorylaimopsis variabilis. Their main densities were all over 4 950 ind./m2. According to mean density at transects, marine nematode density decreased from coastal Weitou to off Minjiang Estuary, which was similar to polychaete distribution in northern Taiwan Strait. The selective deposit feeder (1A) was the dominant food type of marine nematodes in the northern Taiwan Strait, but non-selective deposit feeders (1B) and epigrowth feeders (2A) occupied high proportion, indicating diverse feeding types of marine nematodes in the northern Taiwan Strait. Some environmental factors such as currents are discussed.展开更多
A new free-living marine nematode species Hopperia sinensis sp. nov. from mangrove forests of Fujian Province, China, is identified and illustrated. Hopperia sinensis sp. nov. is characterized by its cephalic setae 2....A new free-living marine nematode species Hopperia sinensis sp. nov. from mangrove forests of Fujian Province, China, is identified and illustrated. Hopperia sinensis sp. nov. is characterized by its cephalic setae 2.4–2.8 μm long or 17%–20% head diameter, and amphids of 2.25–2.5 turns. Lateral differentiation appears with larger, more irregularly distributed dots behind 3–5 transverse rows of dots posterior to amphid. Buccal cavity is consisted of a shallow and weakly sclerotized cup-shaped portion with strongly sclerotized walls of 18–21 μm deep. There are three sclerotized and size-equally pointed teeth at the junction between the two parts. Spicules of 41–45 μm long are slightly curved with broadband velum and central strips at the proximal end. The gubernacula, with apparent lateral guiding pieces, are formed by one central tubular piece that is weakly sclerotized with 11–16 μm long dorso-caudally directed apophyses. There are 13–14 fine tubular precloacal supplements. Conico-cylindrical tail gradually tapers till pointed tail tip. Female is similar to male, but have a longer body and tail. Ovaries are opposed and outstretched, with anterior ovary to the left and posterior ovary to the right of the intestine. A pictorial key to all the valid known species in genus Hopperia is given.展开更多
Two new free-living marine nematode species from the mangrove wetlands of Fujian Province,China are identified and illustrated.Sabatieria conicoseta sp.nov.is characterized by its short conical somatic setae.There are...Two new free-living marine nematode species from the mangrove wetlands of Fujian Province,China are identified and illustrated.Sabatieria conicoseta sp.nov.is characterized by its short conical somatic setae.There are 12–15 tubular pre-cloacal supplements and 12–15μm long straight gubernacular apophyses.Dorylaimopsis papilla sp.nov.is characterized by spicules which are 1.5–1.8 a.b.d.long with media cuticularized strip along entire spicules,and have a cephalated proximal end with small hooked.There are 16–18 small papillate precloacal supplements and 37–40μm long dorso-caudal gubernacular apophyses.展开更多
A hierarchical diversity index—taxonomic distinctness index Δ +, which was first defined by Warwick and Clark in 1998, was employed to evaluate the pollution status of the Bohai Sea with freeliving marine nematodes....A hierarchical diversity index—taxonomic distinctness index Δ +, which was first defined by Warwick and Clark in 1998, was employed to evaluate the pollution status of the Bohai Sea with freeliving marine nematodes. The result showed that the Bohai Bay and other coastal sampling sites might be affected by oil and gas production and other anthropogenic influences. In other words,anthropogenic disturbance was affecting this component of the benthos in these locations. And most offshore sampling sites in the middle of the Bohai Sea were clear and unpolluted.展开更多
Meiofauna (0.031 -0.5 mm) were sampled and studied at a grid of six stations during the cruise of investigation for over winter ground of anchovy (Engraulis japonicus) in the Southern Yellow Sea, China in January 2003...Meiofauna (0.031 -0.5 mm) were sampled and studied at a grid of six stations during the cruise of investigation for over winter ground of anchovy (Engraulis japonicus) in the Southern Yellow Sea, China in January 2003. Total meiofauna individuals averaged (1.162 ±0.347) x 10~6 indm-2 and the corresponding biomass 1.748 ± 0.72 gdwt m-2 with the maximum 2.35gdwtm-2 at Station 9594 and the minimum 0.537 gdwtm- at Station 11794. A total of fourteen taxa were identified. 2 Free living marine nematodes were the most dominant group with an average abundance of (1.026 ± 0.206) x 10~6 indm- , ac-2 counting for 88.5% of total numbers, and an average of 85.4% lived in the surface layer (0-2cm) of sediments. The individ- ual dry weight was calculated, which ranges from 0.01μg to 31.32μg with an average of 0.261μg. One hundred and forty two species or taxa of free-living marine nematodes belonging to 89 genera, 24 families and 4 orders were identified. Six of them were new species. The common dominant species were Dorylaimopsis rabalaisi, Sphaerolaimus balticus, Sphaerolaimus mini- tus, Metalinhomoeus longicauda, Prochromadorella attenuata., Campylaimus sp. 1, Vasostoma sp. 1, Daptonema nor- mandicum, Paramonohystera riemanni, and Promonhystera sp. 1. According to cluster analysis of Primer 5.0, the six stations were clustered into 2 groups with similar species composition at 40% similarity. The species diversity index (H’), evenness index (J) and species richness index (d) of nematode were calculated and analyzed. Correlation analysis with respect to en- vironmental factors showed that the abundance of meiofauna had a significant correlation with the median diameter of sedi- ment (Mdtf). The species richness of nematodes had a highly significant correlation with Chl-a and significant correlations with Pha-a and Chl-a+ Pha-a.展开更多
One new species of free-living marine nematodes Enoplus taipingensis sp.nov.from the rocky intertidal seaweeds in the Taiping Bay,Qingdao is described and illustrated with scanning electron microscopy observation and ...One new species of free-living marine nematodes Enoplus taipingensis sp.nov.from the rocky intertidal seaweeds in the Taiping Bay,Qingdao is described and illustrated with scanning electron microscopy observation and 18S rRNA gene sequence analysis.Enoplus taipingensis is characterized by special arrangement of lateral setae on the tail,three cervical setae,distal structure on the supplement,and much longer body length with bigger De Man ratio "a".Type specimens are deposited in the College of Marine Life Science,Ocean University of China.展开更多
Six species of new records collected from intertidal mangrove/non-mangrove and subtidal cave sediments during a mangrove ecological study (1998-2001) and a marine cave expedition (2002) in Hong Kong waters are redescr...Six species of new records collected from intertidal mangrove/non-mangrove and subtidal cave sediments during a mangrove ecological study (1998-2001) and a marine cave expedition (2002) in Hong Kong waters are redescribed. These include two enoplids: Anoplostoma viviparum in Anoplostomatidae and Trissonchulus janetae in Ironidae, two chromadorids:Paracomesoma dubium and Actarjania splendens in Comesomatidae, and two monhysterids: Parodontophora marina and Parodontophora c.f. danker in Axonolaimidae. Five of them are the first records from China. Ecological and taxonomic remarks are provided and discussed in comparison with the original descriptions.展开更多
文摘Three species in genus Sabatieria and one in genus Cervonema from the East China Sea were recorded. S. breviseta is characterized by uniformly punctuated coarse dots, large amphids of 5.5 turns (♂) and prominent gubernaculum median piece. The characters of S. breviseta agree quite well with the European original descriptions and only differ in the male amphid turns (5.5 vs. 4.0 turns) and unmodified preanal supplements (5-7 vs. 6). S. pulchra can be recognized by amphid 2.75 turns, irregularly arranged lateral dots, and the first three supplements anterior to the anus, which are more widely spaced than the following ones. The excretory system of S. breviseta and S. pulchra shows sexual dimorphism. S. celtica is defined by amphids 2.00-2.25 turns, weakly developed pharyngeal bulb, curved apophyses and 12-13 conspicuous supplements. C. deltensis is characterized by amphids 4.75 turns, ovate pharyngeal posterior bulb, sperm dimorphism, 7 thin preanal supplements, and long tail cylindrical portion (50%-53% of tail length). All the three Sabatieria species are for the first time recorded in Chinese waters. C. deltensis was originally isolated from the Bohai Sea and Yellow Sea and newly recorded in the East China Sea.
基金funded by the National Natural Science Foundation of China (No. 41606119)the Provincial Natural Science Foundation of Fujian (No. 2017J05068)the New Century Outstanding Talents Support Program for Institutions of Higher Learning in Fujian Province and Building Ecological Security for Urban Agglomeration and Integrating Ecological Restoration Techniques for Coastal Zones in Fujian River Deltas (No. 2016YFC0502900)
文摘Mangroves are unique in their biodiversity,but studies on their meiobenthic biodiversity in China are scarce.Despite the importance of mangroves,little work has been done on the classification of nematodes in mangrove wetlands.Fujian Province is the most northern point of China’s natural mangrove distribution,and it is also one of the provinces with the earliest constructed mangrove forest.In this paper,two new free-living marine nematode species of Desmodoridae from the Xiamen mangrove wetlands in China are described.Metachromadora xiamenensis sp.nov.is characterized by a cylindrical body,and smooth head capsule set off from the rest of the body.The cuticle is finely annulated and thickened at the midbody.Lateral ridges run from the posterior end of the pharynx to the middle of the tail.The amphid foveae is loop shaped and opens at the top with a double contour amphidial,pharynx with bipartite cuticularized internal cavity.There are 18 tubular precloacal supplements and tail with three small protuberances.Molgolaimus euryformis sp.nov.is characterized by a relatively short and plump body with finely annulated cuticle,which is particularly obvious in the tail.The head is small and wide with intensive striates.The inner and outer labial sensilla are indistinct with short spicules and ventral apophysis,a gubernaculum with a block-shaped hook,a swollen conical-cylindrical tail and an absence of precloacal supplements.
基金Supported by the National Natural Science Foundation of China(No.41676146)the Science Foundation of Shandong Provincial Education Department(No.J18LE17)
文摘A new free-living marine nematode species of the genus Rhinema belonging to the family Monoposthiidae was collected from marine sediments in the Qiongzhou Strait of the South China Sea,and it is described here as Rhinema longispicula sp.nov.The new species is characterized by coarsely annulated cuticle with 12 longitudinal ridges(alae)marked as reversed V-shaped.The first and second annuli broader and form a kind of a cephalic capsule.The amphideal fovea circular,situated in the middle of the broad second annulus,not surrounded by dense annulations.Buccal cavity cylindrical with a large dorsal tooth.Pharynx with a prominent anterior pharyngeal bulb and an elongated terminal bulb.Elongate spicules strongly curved,with cephalated proximal end and pointed distal end.Gubernaculum boat-shaped,without apophysis.A long and blunt precloacal seta present.Female with two opposed,outstretched ovaries.
文摘One new species of free-living marine nematode of the genus Curvolaimus, Curvolaimus filiformis sp. nov. from the Huanghai Sea isdescribed and illustrated. This new species is characterized by the buccal cavity teeth, large amphids and two ventral seta at the conicalpart of tail. Meanwhile, two new records of genus Halalaimus, Halalaimus longicaudatus and H. isaitshikovi are first reported in China.Types are deposited in the College of Marine Life Sciences, Ocean University of China.
基金This work was supported by the National Key Basic Research Program from the Ministry of Science and Technology of China under contract Nos G19990437 and 2002CB412400the National Natural Science Foundation of China under contract No.40576061.
文摘One new species of free-living marine nematodes Cephalanticoma filicaudata sp. nov. from the Huanghai Sea, China is described and illustrated. Cephalanticoma filicaudata sp. nov. is characterized by well developed cephalic capsule, three teeth at the anterior of oesophagus, excretory pore opens posterior to cervical setae, only two cervical setae per file, body length longer than 5 200 μm, tail long and no ventral-lateral seta between the supplement and the cloacal opening. Types are deposited in the College of Marine Life Sciences, Ocean University of China.
基金supported by the National Natural Science Foundation of China (No.41176107)Open Research Fund Program of Provincial Key Laboratory of Marine Fishery Resources and Eco-environment of Fujian (No.fmfre2014012)the Training Program of Fujian Excellent Talents in University
文摘Two new species of free-living marine nematode from mangrove habitats in Xiamen Bay are identified.Anoplostoma tumidum sp.nov.is characterized by relatively short outer labial setae(0.86–1.00 h.d.),long tail(c 7.2–8.9,c' 8.3–10.5),an instinct swollen distal portion of slender spicule(Sc 94–101 μm),and well developed copulatory bursae without bursal papillae.A.tumidum sp.nov.differs from all valid species of genus Anoplostoma in copulatory apparatus of males with a distinct swollen distal portion of spicule,and a relatively obvious constriction of head.A.paraviviparum sp.nov.is characterized by relatively long outer labial setae(1.11–1.22 h.d.),and tail(c 6.6–8.5,c' 8.6–10.2);elongated spicules with distinct knob-like proximal and pointed distal ends(Sc 46–69 μm);distinct strip-like gubernaculum(length with 11–15μm);well developed copulatory bursae with precloacal papillae and post-cloacal papillae;and a distinct constriction of head.A.paraviviparum sp.nov.is similar to A.viviparum Bastian,1865,but differs in the reproductive mode of female and the constriction of head.
基金The National Natural Science Foundation of China under contract No.30770250the Knowledge Innovation Program of the Chinese Academy of Sciences under contract No.KZCX2-YW-417 to K Xuthe Open Research Cruise offshore China by R/V KE XUE SAN HAO,Institute of Oceanology,Chinese Academy of Sciences (IOCAS) in 2007
文摘One new species of free-living marine nematode Cephalanticoma brevicaudata sp. nov. from the South China Sea is described. Cephalanticoma brevicaudata sp. nov. is characterized by spindle body with relatively short tail; head with cephalic capsule; three teeth at anterior of pharynx; excretory pore opens posterior to cervical setae; three cervical setae per file; spicules arcuate, cephalate and ventrally bent proximally, and blunt distally, 1.8 a.b.d. long, without ventral ala; gubernaculun slender, simple rod, without apophyses; tubular supplement 34 μm long, 2.3 a.b.d. in front of cloaca.
基金The Fundamental Research Funds for Central Universities of the Ministry of Education of China from Ocean University of China under contract Nos 201362018 and 201462008the National Natural Science Foundation of China under contract No.41006081the Scientific Research Award Foundation for Outstanding Middle-aged and Young Scientists of Shandong Province under contract No.BS2013HZ008
文摘A quantitative study on the community structure and biodiversity of free-living marine nematodes and their relationship with environmental factors in the northern South China Sea were carried out based on the samples collected at five stations in the deep sea(from 313 to 1 600 m) and one station in shallow waters(87 m) during the cruise in September, 2010. Results showed that the abundance of marine nematodes ranged from 224 to 1 996 ind./(10 cm2). A total of 69 free-living marine nematode genera, belonging to 26 families and three orders, were identified. The most dominant genera were Sabatieria, Linhystera, Aegialoalaimus and Daptonema according to SIMPER analysis. Results of CLUSTER analysis revealed four types of marine nematode community(or station groups) in the sampling area. In terms of trophic structure, non-selective deposit feeders(1B) and selective deposit feeders(1A) were the dominant trophic types with highest genera numbers and abundances, which implied that organic detritus was the main food source of marine nematodes in the northern South China Sea.The percentage of male nematode was low, ranging from 2.22% to 17.81%, while those of juvenile individuals ranged from 36.99% to 82.09%. For genera level diversity of marine nematodes, Shannon-Wiener diversity indices(H') ranged from 3.76 to 4.57 and had highly significant negative correlation with water depth. In general, diversity indices H' at the five stations in deep sea(over 200 m) were lower than that at the station in shallow waters(87 m).BIOENV analysis showed that the most important environmental factor controlling marine nematode communities was water depth.
基金funded by the National Natural Science Foundation of China (No.41576135)the Fundamental Research Funds for Central Universities of the Ministry of Education of China (No.201462008)the National Key Basic Research Program from the Ministry of Science and Technology,People’s Republic of China (No.G1999043709)
文摘Biodiversity patterns of free-living marine nematodes were studied using specific,taxonomic and phylogenetic diversity measures in the southern Yellow Sea,China.The results showed that the average of Shannon-Wiener diversity index(H′) in the study area was 3.17.The higher values were distributed in the east part of Shandong coastal waters and north part of Jiangsu coastal waters,while the lower values were distributed in the southern Yellow Sea Cold Water Mass(YSCWM).The average of taxonomic diversity(Δ) was 62.09 in the study region.The higher values were distributed in the transitional areas between the coastal areas and the southern YSCWM,while the lower values were distributed near the north part of Jiangsu coastal waters and the YSCWM.Results of correlation analysis of species diversity and taxonomic diversity showed that some of the two kinds of diversity index were independent,which suggested that combining the two kinds of diversity indices can reflect the ecological characteristics better.A test for 95% probability funnels of average taxonomic distinctness and variation in taxonomic distinctness suggested that Station 8794(in the YSCWM) was outside of the 95% probability funnels,which may be due to the environmental stress.Results of correlation analysis between marine nematodes biodiversity and environmental variables showed that the sediment characteristics(Md? and Silt-clay fraction) and phaeophorbide a(Pha-a) were the most important factors to determine the biodiversity patterns of marine nematodes.
基金supported by the Mega-Science Program of the Ministry of Science and Technology of China(2013CB956504)the National Natural Science Foundation of China(40906066)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘Nematodes are small multicellular, thread-like organisms, inhabiting almost all conceivable environments;among these, some 25 % are free-living marine forms with a population density of(1–12) 9 106 inds m-2in seabed sediment, reaching maximum values in muddy estuaries and salt marshes. A large quantity of carbon from the salt marsh plants enters the ecosystem via the detritus pathway,in which nematodes play an important role through their feeding and bioturbation activities. Vegetation influences the sedimentary environment and modifies the distribution pattern of nematode communities in coastal wetlands.Nematodes are coupled closely with bacteria/detritus in microbial food webs, stimulating bacterial growth and subsequent nutrient remineralization; they provide food sources for higher trophic levels and serve as a linkagebetween micro- and macro-fauna. Furthermore, nematodes have a potential to provide proxies that can be used in diagnosing environmental quality. In China, only a limited number of nematode data sets are available for the coastal wetlands across several different climatic zones. It is necessary to carry out additional investigations into the biology and ecology of nematodes in order to delineate their ecological functioning in coastal wetlands. On such a basis,the contribution made by nematodes to material cycling and the ecological functioning in coastal wetlands can be quantified. The assessment of their biological diversity should be a focus, which is fundamental in the study of wetland ecosystem dynamic mechanisms. In addition to laboratory and mesocosm experiments, mathematical models should be established to predict the responses of ecosystem to the environmental disturbance. Finally, it is necessary to improve the techniques for nematode analysis,to enhance the efficiency of data acquisition.
基金This study was supported by the National Natural Science Foundation of China(Nos.41976100,41576153).
文摘Free living marine nematodes were sampled from two sandy beaches in Dalian City,in December of 2015,and April,July,and October of 2016.The spatial and seasonal variations of marine nematode species diversity(based on species abundance dataset)and functional diversity(based on functional traits dataset:feeding types and life history strategies)were investigated to understand the environmental drivers and how they respond to specific environmental variations.Sediment granularity was revealed to be the main environmental factor causing spatial differences in nematode diversity indices between the two beaches.Species diversity indices,namely species number,Margalef index,Shannon-Wiener diversity index(H’),were higher in fine-grained sediments,while the functional diversity indices,including functional evenness,functional dispersion,and Rao’s quadratic entropy index(RaoQ),were higher in coarse-grained sediments.Nematode species diversity indices also fluctuated with seasonal variations of temperature,dissolved oxygen,pH,salinity,and sediment chlorophyll-a within the study beaches.However,functional diversity indices did not show significant seasonal variations and exhibited weak correlation with the studied environmental variables.Overall,the functional diversity indices were negatively correlated with the species diversity indices,suggesting an inconsistent response to environmental changes.A decrease in nematode species diversity in coarse sands,accompanied by an increase in functional diversity,can be regarded as an early warning signal of environment disturbance.If more biological traits are involved in calculating functional diversity indices,it will be helpful for the future study of the internal connections of species diversity and functional diversity.
基金the Key Item of National Natural Science Foundation of China under contract No.49636220.
文摘Marine free-living nematodes were investigated at 13 sampling stations divided into three transects in the northern Taiwan Strait in February 1998. One hundred species of marine nematodes belonging to 91 Genera 28 Families 3 Orders were identified and were first recorded in the northern Taiwan Strait. The dominant species were Vasostoma sp., Sabatieria sp. 1, Linhystera sp. 1, Spilophorella sp., Daptonema sp., Halalaimus sp. and Dorylaimopsis variabilis. Their main densities were all over 4 950 ind./m2. According to mean density at transects, marine nematode density decreased from coastal Weitou to off Minjiang Estuary, which was similar to polychaete distribution in northern Taiwan Strait. The selective deposit feeder (1A) was the dominant food type of marine nematodes in the northern Taiwan Strait, but non-selective deposit feeders (1B) and epigrowth feeders (2A) occupied high proportion, indicating diverse feeding types of marine nematodes in the northern Taiwan Strait. Some environmental factors such as currents are discussed.
基金supported by grants from the National Science Foundation of China(No.41176107)Open Research Fund Program of Fujian Provincial Key Laboratory of Marine Fishery Resources and Eco-environment(No.fmfre2014012)the Training Program of Fujian Excellent Talents in University
文摘A new free-living marine nematode species Hopperia sinensis sp. nov. from mangrove forests of Fujian Province, China, is identified and illustrated. Hopperia sinensis sp. nov. is characterized by its cephalic setae 2.4–2.8 μm long or 17%–20% head diameter, and amphids of 2.25–2.5 turns. Lateral differentiation appears with larger, more irregularly distributed dots behind 3–5 transverse rows of dots posterior to amphid. Buccal cavity is consisted of a shallow and weakly sclerotized cup-shaped portion with strongly sclerotized walls of 18–21 μm deep. There are three sclerotized and size-equally pointed teeth at the junction between the two parts. Spicules of 41–45 μm long are slightly curved with broadband velum and central strips at the proximal end. The gubernacula, with apparent lateral guiding pieces, are formed by one central tubular piece that is weakly sclerotized with 11–16 μm long dorso-caudally directed apophyses. There are 13–14 fine tubular precloacal supplements. Conico-cylindrical tail gradually tapers till pointed tail tip. Female is similar to male, but have a longer body and tail. Ovaries are opposed and outstretched, with anterior ovary to the left and posterior ovary to the right of the intestine. A pictorial key to all the valid known species in genus Hopperia is given.
基金The National Natural Science Foundation of China under contract No.31772416the Science Foundation of Fujian Province under contract No.2017J01450
文摘Two new free-living marine nematode species from the mangrove wetlands of Fujian Province,China are identified and illustrated.Sabatieria conicoseta sp.nov.is characterized by its short conical somatic setae.There are 12–15 tubular pre-cloacal supplements and 12–15μm long straight gubernacular apophyses.Dorylaimopsis papilla sp.nov.is characterized by spicules which are 1.5–1.8 a.b.d.long with media cuticularized strip along entire spicules,and have a cephalated proximal end with small hooked.There are 16–18 small papillate precloacal supplements and 37–40μm long dorso-caudal gubernacular apophyses.
文摘A hierarchical diversity index—taxonomic distinctness index Δ +, which was first defined by Warwick and Clark in 1998, was employed to evaluate the pollution status of the Bohai Sea with freeliving marine nematodes. The result showed that the Bohai Bay and other coastal sampling sites might be affected by oil and gas production and other anthropogenic influences. In other words,anthropogenic disturbance was affecting this component of the benthos in these locations. And most offshore sampling sites in the middle of the Bohai Sea were clear and unpolluted.
基金the National Key Basic Research Program from the Ministry of Science and Technology,P.R.China(Grant No.19990437,2002CB412400)National Science Foundation of China(No.40176033).
文摘Meiofauna (0.031 -0.5 mm) were sampled and studied at a grid of six stations during the cruise of investigation for over winter ground of anchovy (Engraulis japonicus) in the Southern Yellow Sea, China in January 2003. Total meiofauna individuals averaged (1.162 ±0.347) x 10~6 indm-2 and the corresponding biomass 1.748 ± 0.72 gdwt m-2 with the maximum 2.35gdwtm-2 at Station 9594 and the minimum 0.537 gdwtm- at Station 11794. A total of fourteen taxa were identified. 2 Free living marine nematodes were the most dominant group with an average abundance of (1.026 ± 0.206) x 10~6 indm- , ac-2 counting for 88.5% of total numbers, and an average of 85.4% lived in the surface layer (0-2cm) of sediments. The individ- ual dry weight was calculated, which ranges from 0.01μg to 31.32μg with an average of 0.261μg. One hundred and forty two species or taxa of free-living marine nematodes belonging to 89 genera, 24 families and 4 orders were identified. Six of them were new species. The common dominant species were Dorylaimopsis rabalaisi, Sphaerolaimus balticus, Sphaerolaimus mini- tus, Metalinhomoeus longicauda, Prochromadorella attenuata., Campylaimus sp. 1, Vasostoma sp. 1, Daptonema nor- mandicum, Paramonohystera riemanni, and Promonhystera sp. 1. According to cluster analysis of Primer 5.0, the six stations were clustered into 2 groups with similar species composition at 40% similarity. The species diversity index (H’), evenness index (J) and species richness index (d) of nematode were calculated and analyzed. Correlation analysis with respect to en- vironmental factors showed that the abundance of meiofauna had a significant correlation with the median diameter of sedi- ment (Mdtf). The species richness of nematodes had a highly significant correlation with Chl-a and significant correlations with Pha-a and Chl-a+ Pha-a.
基金The National Natural Science Foundation of China under contract Nos 4073087440576061 and 41076090
文摘One new species of free-living marine nematodes Enoplus taipingensis sp.nov.from the rocky intertidal seaweeds in the Taiping Bay,Qingdao is described and illustrated with scanning electron microscopy observation and 18S rRNA gene sequence analysis.Enoplus taipingensis is characterized by special arrangement of lateral setae on the tail,three cervical setae,distal structure on the supplement,and much longer body length with bigger De Man ratio "a".Type specimens are deposited in the College of Marine Life Science,Ocean University of China.
基金funded by National Key Basic Research Program from the Ministry of Science and Technology,People’s Repubfic of China(G 19990437)also supported by the National Natural Science Foundation of China(No.40176033)
文摘Six species of new records collected from intertidal mangrove/non-mangrove and subtidal cave sediments during a mangrove ecological study (1998-2001) and a marine cave expedition (2002) in Hong Kong waters are redescribed. These include two enoplids: Anoplostoma viviparum in Anoplostomatidae and Trissonchulus janetae in Ironidae, two chromadorids:Paracomesoma dubium and Actarjania splendens in Comesomatidae, and two monhysterids: Parodontophora marina and Parodontophora c.f. danker in Axonolaimidae. Five of them are the first records from China. Ecological and taxonomic remarks are provided and discussed in comparison with the original descriptions.