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. Ther...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 12-15/Jm 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 37-40 μm long dorso-caudal gubernacular apophyses.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
Free-living marine nematodes were sampled and studied at a grid of 22 stations (from 32°29.35′ to 37°0.56′N, 122°0.37′ to 125°1.16′ E) in the southern Huanghai Sea in January 2003. Nematode a...Free-living marine nematodes were sampled and studied at a grid of 22 stations (from 32°29.35′ to 37°0.56′N, 122°0.37′ to 125°1.16′ E) in the southern Huanghai Sea in January 2003. Nematode abundance varied from 50.5 to 127.2 ind./cm^2 [(83.1 ±24.7) ind./cm^2] at different stations, 80.1% of the total nematodes were in the surface layer (0-2 cm) of sediments. Two hundred and twenty-three species or taxa of marine nematodes belonging to 145 genera, 32 families and four orders were identified and first recorded in the Huanghai Sea. The common dominant species were Dorylaimopsis rabalaisi, Terschellingia longicaudata, Sphaerolaimus bolticus, Metalinhomoeus longiseta, Quadricoma scanica, Prochromadorella sp., Paramonohystera riemanni, Marylynnia sp. 1, Vasostoma spircaum, Halalaimus spp., Pierrickia sp. 1 and Promonhystera faber. Nematode diversity was correlated with sediment granularity. Pearson correlation analysis showed that Shannon-Wiener index had highly significant positive correlation with a sand content and negative correlation with a silt-clay content (P〈0.01); species richness index (d) had significant positive correlation with the sand content and negative correlation with the silt-clay content (P〈0.05). The diversity of the southern Huanghai Sea was lower than that in the center of Bohai Sea, but the dominance was higher.展开更多
Five species of free-living marine nematodes are redescribed and illustrated as new records in the Yellow Sea of China. These species include one monhysterid, Campylaimus gerlachi in the family Diplopeltidae and four ...Five species of free-living marine nematodes are redescribed and illustrated as new records in the Yellow Sea of China. These species include one monhysterid, Campylaimus gerlachi in the family Diplopeltidae and four enoplids species, Oxystomina elongata, Oxystomina elegans, Halalaimus lutarus and Halalaimus wodjanizkii in the family Oxystominidae. Ecological and taxonomic remarks are provided and discussed in comparison with the original description. The key to all known species of the genus Campylaimus is given. Our findings have offerred the taxonomic information of nematodes to the benthic ecology and biodiversity studies of the Yellow Sea.展开更多
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
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 shallowwaters (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 denth.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
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; guberaaculun slender, simple rod, without apophyses; tubular supplement 34μm long, 2.3 a.b.d. in front of cloaca.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
Actinonemafalciforrne sp. nov. was discovered from the continental-shelf sediments of the East China Sea. It is characterized by six outer labial setae and four cephalic setae in one circle, complex and heterogeneous ...Actinonemafalciforrne sp. nov. was discovered from the continental-shelf sediments of the East China Sea. It is characterized by six outer labial setae and four cephalic setae in one circle, complex and heterogeneous cuticular ornamentation with lateral differentiation, large and conspicuous amphideal fovea which is transversely ovalshaped, a single anterior testis, two opposed reflexed ovaries, falciform telamon (lateral pieces of gubernaculum), and the lack of spicule and gubernaculum. Within the genus Actinonema, only A. longicaudatum and the new species possess telamon and lack spicule and gubernaculum. Actinonemafalciforme sp. nov. can be easily differentiated from A. longicaudatum by its much shorter body length, the peculiar shape of the telamon and a shorter tail.展开更多
In this study, qPCR was used to quantify opportunistic premise plumbing pathogens(OPPPs) and free-living amoebae in 11 tap water samples collected over four seasons from a city in northern China. Results demonstrated ...In this study, qPCR was used to quantify opportunistic premise plumbing pathogens(OPPPs) and free-living amoebae in 11 tap water samples collected over four seasons from a city in northern China. Results demonstrated that the average numbers of gene copies of Legionella spp. and Mycobacterium spp. were significantly higher than those of Aeromonas spp.(p < 0.05). Legionella spp. and Mycobacterium spp. were 100%(44/44) positively detected while P. aeruginosa and Aeromonas spp. were 79.54%(35/44) and 77.27%(34/44) positively detected. Legionella pneumophila was only detected in 4 samples(4/44), demonstrating its occasional occurrence. No Mycobacterium avium or Naegleria fowleri was detected in any of the samples. The average gene copy numbers of target OPPPs were the highest in summer,suggesting seasonal prevalence of OPPPs. Average gene copy numbers of OPPPs in the taps of low-use-frequency were higher than in taps of high-use-frequency, but the difference was not significant for some OPPPs(p > 0.05). Moderate negative correlations between the chlorine concentration and the gene copy numbers of OPPPs were observed by Spearman analysis(rsranged from -0.311 to -0.710, p < 0.05). However, no significant correlations existed between OPPPs and AOC, BDOC, or turbidity. Moderate positive correlations were observed between the target microorganisms, especially for Acanthamoeba spp., through Spearman analysis(p < 0.05). Based on our studies, it is proposed that disinfectant concentration, season, taps with different-use frequency, OPPP species, and potential microbial correlations should be considered for control of OPPPs in tap water.展开更多
Background:Acinetobacter baumannii is ubiquitous,facultative intracellular,and opportunistic bacterial pathogen.Its unique abilities allow it to survive in a diverse range of environments,including health care setting...Background:Acinetobacter baumannii is ubiquitous,facultative intracellular,and opportunistic bacterial pathogen.Its unique abilities allow it to survive in a diverse range of environments,including health care settings,leading to nosocomial infections.And its exceptional ability to develop resistance to multiple antibiotics leaves few drug options for treatment.It has been recognized as a leading cause of nosocomial pneumonia and bacteremia over the world.Case presentation:In this case,a 73-year-old woman presented with a Neer Group VI proximal humeral fracture.Six hours after a successfully performed hemiarthroplasty,she developed continuous fever.Clinical examination revealed that the vitals were regular.Laboratory and radiographic examinations revealed only elevated procalcitonin levels.Blood culture revealed no bacterial or fungal growth.Cooling treatment and empirical broad-spectrum antibiotic therapy showed no apparent effect.Conclusions:We report a postoperative infection caused by Acinetobacter baumannii.The infectious pathogen was identified via molecular DNA sequencing and was initially misidentified as a free-living amoeba species upon microscopic examinations.The patient was mistreated with antiamebic combination therapy.Her symptoms persisted for over 4 months and were eventually followed by her death.展开更多
Background:Pathogenic water dwelling protozoa such as Acanthamoeba spp.,Hartmannella spp.,Naegleria spp.,Cryptosporidium spp.and Giardia spp.are often responsible for devastating illnesses especially in children and i...Background:Pathogenic water dwelling protozoa such as Acanthamoeba spp.,Hartmannella spp.,Naegleria spp.,Cryptosporidium spp.and Giardia spp.are often responsible for devastating illnesses especially in children and immunocompromised individuals,yet their presence and prevalence in certain environment in sub-Saharan Africa is still unknown to most researchers,public health officials and medical practitioners.The objective of this study was to establish the presence and prevalence of pathogenic free-living amoeba(FLA),Cryptosporidium and Giardia in Queen Elizabeth Protected Area(QEPA).Methods:Samples were collected from communal taps and natural water sites in QEPA.Physical water parameters were measured in situ.The samples were processed to detect the presence of FLA trophozoites by xenic cultivation,Cryptosporidium oocysts by Ziehl-Neelsen stain and Giardia cysts by Zinc Sulphate floatation technique.Parasites were observed microscopically,identified,counted and recorded.For FLA,genomic DNA was extracted for amplification and sequencing.Results:Both natural and tap water sources were contaminated with FLA,Cryptosporidium spp.and Giardia spp.All protozoan parasites were more abundant in the colder rainy season except for Harmannella spp.and Naegleria spp.which occurred more in the warmer months.The prevalence of all parasites was higher in tap water than in natural water samples.There was a strong negative correlation between the presence of Acanthamoeba spp.,Hartmannella spp.,Cryptosporidium spp.and Giardia spp.with Dissolved Oxygen(DO)(P<0.05).The presence of Cryptosporidium spp.showed a significant positive correlation(P<0.05)with conductivity,pH and Total Dissolved Solids(TDS);whereas the presence of Giardia spp.had only a strong positive correlation with TDS.Molecular genotyping of FLA produced 7 Acanthamoeba,5 Echinamoeba,2 Hartmannella,1 Bodomorpha,1 Nuclearia and 1 Cercomonas partial sequences.Conclusions:All water collection sites were found to be contaminated with pathogenic protozoa that could possibly be the cause of a number of silent morbidities and mortalities among rural households in QEPA.This implies that water used by communities in QEPA is of poor quality and predisposes them to a variety of protozoan infections including the FLA whose public health importance was never reported,thus necessitating adoption of proper water safety measures.展开更多
[Objectives]To study the differences of growth rate,morphology,ultrastructure,pigment content and antioxidant enzyme activity of free-living conchocelis of cultivated type of Neopyropia yezoensis under different light...[Objectives]To study the differences of growth rate,morphology,ultrastructure,pigment content and antioxidant enzyme activity of free-living conchocelis of cultivated type of Neopyropia yezoensis under different light qualities(white,red,blue,and green light).[Methods]The study was carried out through light quality design and culture,growth rate determination,microstructure and ultrastructure observation,chlorophyll a content and carotenoid content determination,phycobiliprotein content determination,malondialdehyde(MDA)content determination,superoxide dismutase(SOD)activity determination.[Results]After 21 d of culture,the specific growth rate(SGR)and chlorophyll a content of free-living conchocelis of N.yezoensis were significantly increased by white light(WL),followed by red light(RL)and green light(GL),and they were the lowest under blue light(BL).Compared with the WL group,the BL group had the highest content of phycoerythrin(PE),and the RL and GL groups had the highest content of phycocyanin(PC).The algal body of WL group was normal black brown,and the cell wall was the thickest.In RL and GL groups,the algal bodies were green,and their diameters and cell wall thicknesses were similar to those in WL group.In BL group,the algal body was bright red,the diameter was the smallest,the cell wall was the thinnest,and the ultrastructure showed that the number of plastoglobulus on the thylakoid was the largest.After BL irradiation,the highest MDA content and the lowest SOD activity were observed.The results revealed that WL is the most beneficial to the growth of free-living conchocelis,followed by RL and GL,while BL has adverse effects.[Conclusions]This study explored the most suitable light quality conditions for the propagation of free-living conchocelis.It is expected to provide germplasm guarantee for the production and seedling of N.yezoensis.展开更多
A quantitative study on meiofauna was carried out along a transect throughout the Changjiang Estuary' s oxygen minimum zone (OMZ) in the East China Sea. There exist two distinct station groups in the OMZ: the fine...A quantitative study on meiofauna was carried out along a transect throughout the Changjiang Estuary' s oxygen minimum zone (OMZ) in the East China Sea. There exist two distinct station groups in the OMZ: the fine-grained hypoxic area and the more fine-grained anoxie area. Meiofauna abundance ranged from ( 101.5±31.0) ind./cm^2 ( hypoxie area) to (369.9±123.9) ind./cm^2( anoxic area) along the transect. Free-living marine nematodes were the numerically dominant meiofauna at every station. The anoxic area differed significantly in meiofauna abundance and vertical distribution pattern from the hypoxic area. Within the anoxic area, nematodes abundance increased and amounted to over 90% of the total meiofauna; about 50% of nematodes were found in the 2-5 and 5-8 cm layers. At hypoxie stations, about over 85 % were restricted to the top 2 cm. Benthic eopepod abundance and dominance decreased consistently with the oxygen gradient. The pattern of meiofauna biomass was similar to that of abundance. The correlation analysis of the meiofauna numbers and environmental parameters indicated that abundance and biomass of total meiofauna and nematodes had significant or highly significant ( P 〈 0.05 or P 〈 0.01 ) correlations with Chl a and Pha a, but no significant ( P 〉 0.05 ) correlations with bottom-water oxygen ( BWO2 ). On the other hand, there was a highly significant positive correlation between benthic eopepod abundance and bottom-water oxygen (P 〈 0.05 ). The investigation on the nematode community structure indicated that two different nematode communities existed in hypoxic and anoxic areas. In certain way, the shift in nematode species composition distinguishes the anoxia to hypoxia. Nematode diversity was generally lower within the anoxic stations than the hypoxic ones, but the difference was not significant. Indices of the nematode community structure varied in relation to the bottom-water oxygen together with bottom-water temperature, Chl a concentration and median grain size of sediment.展开更多
Meiofauna (0.031-0.5 mm) were sampled and studied at a grid of six stationsduring the cruise of investigation for over winter ground of anchovy (Engraulis japonicus) in theSouthern Yellow Sea, China in January 2003. T...Meiofauna (0.031-0.5 mm) were sampled and studied at a grid of six stationsduring the cruise of investigation for over winter ground of anchovy (Engraulis japonicus) in theSouthern Yellow Sea, China in January 2003. Total meiofauna individuals averaged (1.162 ± 0.347) x10^6 ind m^(-2) and the corresponding biomass 1.748 ± 0.72 g dwt m^(-2) with the maximum 2.35 g dwtm^(-2) at Station 9594 and the minimum 0.537 g dwt m^(-2) at Station 11794. A total of fourteentaxa were identified. Free living marine nematodes were the most dominant group with an averageabundance of (1.026 ± 0.206) x 10~6 ind m^(-2), accounting for 88.5% of total numbers, and anaverage of 85.4% lived in the surface layer (0-2cm) of sediments. The individual dry weight wascalculated, which ranges from 0.01 μg to 31.32 μg with an average of 0.261 μg. One hundred andforty two species or taxa of free-living marine nematodes belonging to 89 genera, 24 families and 4orders were identified. Six of them were new species. The common dominant species were Dorylaimopsisrabalaisi, 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, thesix stations were clustered into 2 groups with similar species composition at 40% similarity. Thespecies diversity index (H′), evenness index (J) and species richness index (d) of nematode werecalculated and analyzed. Correlation analysis with respect to environmental factors showed that theabundance of meiofauna had a significant correlation with the median diameter of sediment (Md_φ).The species richness of nematodes had a highly significant correlation with Chl-a and significantcorrelations with Pha-a and Chl-a + Pha-a.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
A grid of 22 stations, giving a broad geographic coverage of the Bohai Sea and the Bohai Strait was selected. Undisturbed sediments were collected from sampling stations during cruises in June 1997, in September/Octob...A grid of 22 stations, giving a broad geographic coverage of the Bohai Sea and the Bohai Strait was selected. Undisturbed sediments were collected from sampling stations during cruises in June 1997, in September/October 1998 and again in April/May 1999. Based on the results of Juario (1975), the average biomass, 0.404 g/(m2a) of meiofauna (including nematode, harpacticoida, bivalve larvae, polycheata and kinorhyncha) in the Bohai Sea is given and accounts for 4.5 percent of the macrofauna in the Bohai Sea. The horizontal distribution of the biomass of meiofauna showed that it was higher at the stations of middle east part of the Bohai Sea and the strait in 1998 and 1999 cruises and it decreased at the stations near to the strait mouth and increased at Station B1 in 1999 cruise. The annual average production in the Bohai Sea is 3.636 g/m2 calculated in term of the formula P = 9B. Compared with the biomass of other sea areas in the world, the biomass of the Bohai Sea is similar but slightly lower. The individual average dry weight of nematodes given by different authors is analyzed.展开更多
The Three Gorges Dam (TGD) of the Yangtze River, China, is one of the largest irrigation and hydroelectric engineering projects in the world. The effects of huge man-made projects like TGD on fauna and macrophyte ar...The Three Gorges Dam (TGD) of the Yangtze River, China, is one of the largest irrigation and hydroelectric engineering projects in the world. The effects of huge man-made projects like TGD on fauna and macrophyte are obvious, mainly through changes of water dynamics and flow pattern; however, it is less clear how microorganisms respond to such changes. This research was aimed to examine differences in microbial diversity at different seasons and locations (in front of and behind the TGD). In addition, differences between particle-attached and free-living communities were also examined. The community structures of total and potentially active microorganisms in the water columns behind and in front of the TGD were analyzed with the DNA- and RNA-based 16S rRNA gene phylogenetic approaches over three different seasons. Clone libraries of 16S rRNA genes were prepared after ampli- fication from extracted DNA and, for some samples, after preparing cDNA from extracted rRNA. Differ- ences were observed between sites at different seasons and between free-living and particle-attached communities. Both bacterial and archaeal communities were more diverse in summer than in winter, due to higher nutrient levels and warmer temperature in summer than in winter. Particle-attached micro- organisms were more diverse than free-living communities, possibly because of higher nutrient levels and heterogeneous geochemical micro-environments in particles. Spatial variations in bacterial community structure were observed, i.e., the water reservoir behind the TGD (upstream) hosted more diverse bacte- rial populations than in front of the dam (downstream), because of diverse sources of sediments and waters from upstream to the reservoir. These results have important implications for our understanding of responses of microbial communities to environmental changes in river ecosystems affected by dam construction.展开更多
Background: Bringing free-living animals into captivity subjects them to the stress of both capture and captivity, leading to the alteration of normal physiological processes and behaviors through activation of the hy...Background: Bringing free-living animals into captivity subjects them to the stress of both capture and captivity, leading to the alteration of normal physiological processes and behaviors through activation of the hypothalamic– pituitary–adrenal axis. In free-living birds, although elevated plasma corticosterone (CORT) is an important adaptation regulating physiological and behavioral responses during the process of capture and captivity stress, little information is currently available on the effects of such stress on plasma metabolite levels. Methods: We examined the effects of immediate capture and 24-h captivity on body mass, body condition, plasma CORT, and metabolite levels including glucose (Glu), triglyceride (TG), total cholesterol (TC), uric acid (UA), in breeding Eurasian Tree Sparrows (Passer montanus). Results: CORT and Glu levels were increased significantly by the stress of capture, whereas TC and UA levels decreased. Body mass, body condition declined notably after 24 h in captivity, but CORT, Glu, and UA levels increased. Furthermore, male sparrows had lower TG levels after both capture and captivity than those of females. The relationships between plasma CORT and metabolite levels varied between sexes. Conclusions: Our results revealed that the metabolic status of Eurasian Tree Sparrows could be dramatically altered by capture and captivity. Monitoring the dynamic effects of both capture and captivity on plasma CORT, metabolite levels in a free-living bird contributes to a better understanding of the stress-induced pathways involved in sexdependent energy mobilization.展开更多
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 12-15/Jm 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 37-40 μm long dorso-caudal gubernacular apophyses.
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.
文摘Free-living marine nematodes were sampled and studied at a grid of 22 stations (from 32°29.35′ to 37°0.56′N, 122°0.37′ to 125°1.16′ E) in the southern Huanghai Sea in January 2003. Nematode abundance varied from 50.5 to 127.2 ind./cm^2 [(83.1 ±24.7) ind./cm^2] at different stations, 80.1% of the total nematodes were in the surface layer (0-2 cm) of sediments. Two hundred and twenty-three species or taxa of marine nematodes belonging to 145 genera, 32 families and four orders were identified and first recorded in the Huanghai Sea. The common dominant species were Dorylaimopsis rabalaisi, Terschellingia longicaudata, Sphaerolaimus bolticus, Metalinhomoeus longiseta, Quadricoma scanica, Prochromadorella sp., Paramonohystera riemanni, Marylynnia sp. 1, Vasostoma spircaum, Halalaimus spp., Pierrickia sp. 1 and Promonhystera faber. Nematode diversity was correlated with sediment granularity. Pearson correlation analysis showed that Shannon-Wiener index had highly significant positive correlation with a sand content and negative correlation with a silt-clay content (P〈0.01); species richness index (d) had significant positive correlation with the sand content and negative correlation with the silt-clay content (P〈0.05). The diversity of the southern Huanghai Sea was lower than that in the center of Bohai Sea, but the dominance was higher.
文摘Five species of free-living marine nematodes are redescribed and illustrated as new records in the Yellow Sea of China. These species include one monhysterid, Campylaimus gerlachi in the family Diplopeltidae and four enoplids species, Oxystomina elongata, Oxystomina elegans, Halalaimus lutarus and Halalaimus wodjanizkii in the family Oxystominidae. Ecological and taxonomic remarks are provided and discussed in comparison with the original description. The key to all known species of the genus Campylaimus is given. Our findings have offerred the taxonomic information of nematodes to the benthic ecology and biodiversity studies of the Yellow Sea.
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 shallowwaters (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 denth.
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; guberaaculun slender, simple rod, without apophyses; tubular supplement 34μm long, 2.3 a.b.d. in front of cloaca.
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.
基金The Strategic Priority Research Program of the Chinese Academy of Sciences under contract No.XDA11030201the National Natural Science Foundation of China under contract No.41706163China Postdoctoral Science Foundation under contract No.2016M602201
文摘Actinonemafalciforrne sp. nov. was discovered from the continental-shelf sediments of the East China Sea. It is characterized by six outer labial setae and four cephalic setae in one circle, complex and heterogeneous cuticular ornamentation with lateral differentiation, large and conspicuous amphideal fovea which is transversely ovalshaped, a single anterior testis, two opposed reflexed ovaries, falciform telamon (lateral pieces of gubernaculum), and the lack of spicule and gubernaculum. Within the genus Actinonema, only A. longicaudatum and the new species possess telamon and lack spicule and gubernaculum. Actinonemafalciforme sp. nov. can be easily differentiated from A. longicaudatum by its much shorter body length, the peculiar shape of the telamon and a shorter tail.
基金supported by the National Key Research and Development Plan(No.2016YFA0203200)the National Natural Science Foundation of China(No.51538013)the project of Chinese Academy of Sciences(No.QYZDY-SSW-DQC004)
文摘In this study, qPCR was used to quantify opportunistic premise plumbing pathogens(OPPPs) and free-living amoebae in 11 tap water samples collected over four seasons from a city in northern China. Results demonstrated that the average numbers of gene copies of Legionella spp. and Mycobacterium spp. were significantly higher than those of Aeromonas spp.(p < 0.05). Legionella spp. and Mycobacterium spp. were 100%(44/44) positively detected while P. aeruginosa and Aeromonas spp. were 79.54%(35/44) and 77.27%(34/44) positively detected. Legionella pneumophila was only detected in 4 samples(4/44), demonstrating its occasional occurrence. No Mycobacterium avium or Naegleria fowleri was detected in any of the samples. The average gene copy numbers of target OPPPs were the highest in summer,suggesting seasonal prevalence of OPPPs. Average gene copy numbers of OPPPs in the taps of low-use-frequency were higher than in taps of high-use-frequency, but the difference was not significant for some OPPPs(p > 0.05). Moderate negative correlations between the chlorine concentration and the gene copy numbers of OPPPs were observed by Spearman analysis(rsranged from -0.311 to -0.710, p < 0.05). However, no significant correlations existed between OPPPs and AOC, BDOC, or turbidity. Moderate positive correlations were observed between the target microorganisms, especially for Acanthamoeba spp., through Spearman analysis(p < 0.05). Based on our studies, it is proposed that disinfectant concentration, season, taps with different-use frequency, OPPP species, and potential microbial correlations should be considered for control of OPPPs in tap water.
基金This work was supported by grants from National Natural Science Foundation of China(31271015)Key Basic Research Project of Science and Technology of Shanghai(13JC1403900).
文摘Background:Acinetobacter baumannii is ubiquitous,facultative intracellular,and opportunistic bacterial pathogen.Its unique abilities allow it to survive in a diverse range of environments,including health care settings,leading to nosocomial infections.And its exceptional ability to develop resistance to multiple antibiotics leaves few drug options for treatment.It has been recognized as a leading cause of nosocomial pneumonia and bacteremia over the world.Case presentation:In this case,a 73-year-old woman presented with a Neer Group VI proximal humeral fracture.Six hours after a successfully performed hemiarthroplasty,she developed continuous fever.Clinical examination revealed that the vitals were regular.Laboratory and radiographic examinations revealed only elevated procalcitonin levels.Blood culture revealed no bacterial or fungal growth.Cooling treatment and empirical broad-spectrum antibiotic therapy showed no apparent effect.Conclusions:We report a postoperative infection caused by Acinetobacter baumannii.The infectious pathogen was identified via molecular DNA sequencing and was initially misidentified as a free-living amoeba species upon microscopic examinations.The patient was mistreated with antiamebic combination therapy.Her symptoms persisted for over 4 months and were eventually followed by her death.
基金The researchers would like to thank WaterNet,SIG-RISE and CARNEGIE-Next Generation of African Academics(NGAA-Carnegie),for supporting and funding this research,and Molecular Biology Laboratory,Makerere University for the equipment used in the diagnostics.
文摘Background:Pathogenic water dwelling protozoa such as Acanthamoeba spp.,Hartmannella spp.,Naegleria spp.,Cryptosporidium spp.and Giardia spp.are often responsible for devastating illnesses especially in children and immunocompromised individuals,yet their presence and prevalence in certain environment in sub-Saharan Africa is still unknown to most researchers,public health officials and medical practitioners.The objective of this study was to establish the presence and prevalence of pathogenic free-living amoeba(FLA),Cryptosporidium and Giardia in Queen Elizabeth Protected Area(QEPA).Methods:Samples were collected from communal taps and natural water sites in QEPA.Physical water parameters were measured in situ.The samples were processed to detect the presence of FLA trophozoites by xenic cultivation,Cryptosporidium oocysts by Ziehl-Neelsen stain and Giardia cysts by Zinc Sulphate floatation technique.Parasites were observed microscopically,identified,counted and recorded.For FLA,genomic DNA was extracted for amplification and sequencing.Results:Both natural and tap water sources were contaminated with FLA,Cryptosporidium spp.and Giardia spp.All protozoan parasites were more abundant in the colder rainy season except for Harmannella spp.and Naegleria spp.which occurred more in the warmer months.The prevalence of all parasites was higher in tap water than in natural water samples.There was a strong negative correlation between the presence of Acanthamoeba spp.,Hartmannella spp.,Cryptosporidium spp.and Giardia spp.with Dissolved Oxygen(DO)(P<0.05).The presence of Cryptosporidium spp.showed a significant positive correlation(P<0.05)with conductivity,pH and Total Dissolved Solids(TDS);whereas the presence of Giardia spp.had only a strong positive correlation with TDS.Molecular genotyping of FLA produced 7 Acanthamoeba,5 Echinamoeba,2 Hartmannella,1 Bodomorpha,1 Nuclearia and 1 Cercomonas partial sequences.Conclusions:All water collection sites were found to be contaminated with pathogenic protozoa that could possibly be the cause of a number of silent morbidities and mortalities among rural households in QEPA.This implies that water used by communities in QEPA is of poor quality and predisposes them to a variety of protozoan infections including the FLA whose public health importance was never reported,thus necessitating adoption of proper water safety measures.
基金Supported by National Algae System(CARS-50)Modern Agricultural(Laver)Industrial Technology System of Jiangsu Province(JATS[2023]381)Research Project of Nantong City(MS22022065).
文摘[Objectives]To study the differences of growth rate,morphology,ultrastructure,pigment content and antioxidant enzyme activity of free-living conchocelis of cultivated type of Neopyropia yezoensis under different light qualities(white,red,blue,and green light).[Methods]The study was carried out through light quality design and culture,growth rate determination,microstructure and ultrastructure observation,chlorophyll a content and carotenoid content determination,phycobiliprotein content determination,malondialdehyde(MDA)content determination,superoxide dismutase(SOD)activity determination.[Results]After 21 d of culture,the specific growth rate(SGR)and chlorophyll a content of free-living conchocelis of N.yezoensis were significantly increased by white light(WL),followed by red light(RL)and green light(GL),and they were the lowest under blue light(BL).Compared with the WL group,the BL group had the highest content of phycoerythrin(PE),and the RL and GL groups had the highest content of phycocyanin(PC).The algal body of WL group was normal black brown,and the cell wall was the thickest.In RL and GL groups,the algal bodies were green,and their diameters and cell wall thicknesses were similar to those in WL group.In BL group,the algal body was bright red,the diameter was the smallest,the cell wall was the thinnest,and the ultrastructure showed that the number of plastoglobulus on the thylakoid was the largest.After BL irradiation,the highest MDA content and the lowest SOD activity were observed.The results revealed that WL is the most beneficial to the growth of free-living conchocelis,followed by RL and GL,while BL has adverse effects.[Conclusions]This study explored the most suitable light quality conditions for the propagation of free-living conchocelis.It is expected to provide germplasm guarantee for the production and seedling of N.yezoensis.
基金the Ministry of Science and Technology of China under contract Nos 2002CB412400,G1999043709the National Natural Science Foundation of China under contract No.40176033.
文摘A quantitative study on meiofauna was carried out along a transect throughout the Changjiang Estuary' s oxygen minimum zone (OMZ) in the East China Sea. There exist two distinct station groups in the OMZ: the fine-grained hypoxic area and the more fine-grained anoxie area. Meiofauna abundance ranged from ( 101.5±31.0) ind./cm^2 ( hypoxie area) to (369.9±123.9) ind./cm^2( anoxic area) along the transect. Free-living marine nematodes were the numerically dominant meiofauna at every station. The anoxic area differed significantly in meiofauna abundance and vertical distribution pattern from the hypoxic area. Within the anoxic area, nematodes abundance increased and amounted to over 90% of the total meiofauna; about 50% of nematodes were found in the 2-5 and 5-8 cm layers. At hypoxie stations, about over 85 % were restricted to the top 2 cm. Benthic eopepod abundance and dominance decreased consistently with the oxygen gradient. The pattern of meiofauna biomass was similar to that of abundance. The correlation analysis of the meiofauna numbers and environmental parameters indicated that abundance and biomass of total meiofauna and nematodes had significant or highly significant ( P 〈 0.05 or P 〈 0.01 ) correlations with Chl a and Pha a, but no significant ( P 〉 0.05 ) correlations with bottom-water oxygen ( BWO2 ). On the other hand, there was a highly significant positive correlation between benthic eopepod abundance and bottom-water oxygen (P 〈 0.05 ). The investigation on the nematode community structure indicated that two different nematode communities existed in hypoxic and anoxic areas. In certain way, the shift in nematode species composition distinguishes the anoxia to hypoxia. Nematode diversity was generally lower within the anoxic stations than the hypoxic ones, but the difference was not significant. Indices of the nematode community structure varied in relation to the bottom-water oxygen together with bottom-water temperature, Chl a concentration and median grain size of sediment.
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 stationsduring the cruise of investigation for over winter ground of anchovy (Engraulis japonicus) in theSouthern Yellow Sea, China in January 2003. Total meiofauna individuals averaged (1.162 ± 0.347) x10^6 ind m^(-2) and the corresponding biomass 1.748 ± 0.72 g dwt m^(-2) with the maximum 2.35 g dwtm^(-2) at Station 9594 and the minimum 0.537 g dwt m^(-2) at Station 11794. A total of fourteentaxa were identified. Free living marine nematodes were the most dominant group with an averageabundance of (1.026 ± 0.206) x 10~6 ind m^(-2), accounting for 88.5% of total numbers, and anaverage of 85.4% lived in the surface layer (0-2cm) of sediments. The individual dry weight wascalculated, which ranges from 0.01 μg to 31.32 μg with an average of 0.261 μg. One hundred andforty two species or taxa of free-living marine nematodes belonging to 89 genera, 24 families and 4orders were identified. Six of them were new species. The common dominant species were Dorylaimopsisrabalaisi, 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, thesix stations were clustered into 2 groups with similar species composition at 40% similarity. Thespecies diversity index (H′), evenness index (J) and species richness index (d) of nematode werecalculated and analyzed. Correlation analysis with respect to environmental factors showed that theabundance of meiofauna had a significant correlation with the median diameter of sediment (Md_φ).The species richness of nematodes had a highly significant correlation with Chl-a and significantcorrelations with Pha-a and Chl-a + Pha-a.
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 project was supported by Darwin Initiative Project from Department of Environment. UK National Natural Science Foundatio
文摘A grid of 22 stations, giving a broad geographic coverage of the Bohai Sea and the Bohai Strait was selected. Undisturbed sediments were collected from sampling stations during cruises in June 1997, in September/October 1998 and again in April/May 1999. Based on the results of Juario (1975), the average biomass, 0.404 g/(m2a) of meiofauna (including nematode, harpacticoida, bivalve larvae, polycheata and kinorhyncha) in the Bohai Sea is given and accounts for 4.5 percent of the macrofauna in the Bohai Sea. The horizontal distribution of the biomass of meiofauna showed that it was higher at the stations of middle east part of the Bohai Sea and the strait in 1998 and 1999 cruises and it decreased at the stations near to the strait mouth and increased at Station B1 in 1999 cruise. The annual average production in the Bohai Sea is 3.636 g/m2 calculated in term of the formula P = 9B. Compared with the biomass of other sea areas in the world, the biomass of the Bohai Sea is similar but slightly lower. The individual average dry weight of nematodes given by different authors is analyzed.
基金supported by the special funds for Outstanding Research Talents of CUG(007-1323511005)the Three Gorges Research Center for geo-hazard,the Ministry of Education (TGRC201023) of China University of Geosciences - Wuhan (CUG)+2 种基金the Research Funds from State Key Laboratory of Biogeology and Environmental Geology,CUG(BGEG 1001)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry,the Fundamental Research Funds for the Central Universities(CUGLI00601)the Lecturer Professorship at the State Key Laboratory of Marine Geology.Tongji University
文摘The Three Gorges Dam (TGD) of the Yangtze River, China, is one of the largest irrigation and hydroelectric engineering projects in the world. The effects of huge man-made projects like TGD on fauna and macrophyte are obvious, mainly through changes of water dynamics and flow pattern; however, it is less clear how microorganisms respond to such changes. This research was aimed to examine differences in microbial diversity at different seasons and locations (in front of and behind the TGD). In addition, differences between particle-attached and free-living communities were also examined. The community structures of total and potentially active microorganisms in the water columns behind and in front of the TGD were analyzed with the DNA- and RNA-based 16S rRNA gene phylogenetic approaches over three different seasons. Clone libraries of 16S rRNA genes were prepared after ampli- fication from extracted DNA and, for some samples, after preparing cDNA from extracted rRNA. Differ- ences were observed between sites at different seasons and between free-living and particle-attached communities. Both bacterial and archaeal communities were more diverse in summer than in winter, due to higher nutrient levels and warmer temperature in summer than in winter. Particle-attached micro- organisms were more diverse than free-living communities, possibly because of higher nutrient levels and heterogeneous geochemical micro-environments in particles. Spatial variations in bacterial community structure were observed, i.e., the water reservoir behind the TGD (upstream) hosted more diverse bacte- rial populations than in front of the dam (downstream), because of diverse sources of sediments and waters from upstream to the reservoir. These results have important implications for our understanding of responses of microbial communities to environmental changes in river ecosystems affected by dam construction.
基金supported by the National Natural Science Foundation of China(NSFC,31672292)the Natural Science Foundation of Hebei Province(C2017205059)+1 种基金the foundation of China Scholarship Council(201408130068) to D.Lithe NSFC(31770445)to Y.Wu,the NSFC(31372201)to X.Gao
文摘Background: Bringing free-living animals into captivity subjects them to the stress of both capture and captivity, leading to the alteration of normal physiological processes and behaviors through activation of the hypothalamic– pituitary–adrenal axis. In free-living birds, although elevated plasma corticosterone (CORT) is an important adaptation regulating physiological and behavioral responses during the process of capture and captivity stress, little information is currently available on the effects of such stress on plasma metabolite levels. Methods: We examined the effects of immediate capture and 24-h captivity on body mass, body condition, plasma CORT, and metabolite levels including glucose (Glu), triglyceride (TG), total cholesterol (TC), uric acid (UA), in breeding Eurasian Tree Sparrows (Passer montanus). Results: CORT and Glu levels were increased significantly by the stress of capture, whereas TC and UA levels decreased. Body mass, body condition declined notably after 24 h in captivity, but CORT, Glu, and UA levels increased. Furthermore, male sparrows had lower TG levels after both capture and captivity than those of females. The relationships between plasma CORT and metabolite levels varied between sexes. Conclusions: Our results revealed that the metabolic status of Eurasian Tree Sparrows could be dramatically altered by capture and captivity. Monitoring the dynamic effects of both capture and captivity on plasma CORT, metabolite levels in a free-living bird contributes to a better understanding of the stress-induced pathways involved in sexdependent energy mobilization.