Distribution of helminths in the digestive tracts of New Zealand freshwater eels     

P. M. Hine 《新西兰海洋与淡水研究杂志》2013,47(4):339-347

The distributions of the nematode parasites Paraquimperia sp., Spirocamallanus sp., and Cucullanus sp. in the intestines and recta of Anguilla dieffenbachii and A. australis from Lake Ellesmere and the South Branch of the Waimakariri River were studied over two years. Peak occurrence of Paraquimperia was in the anterior intestine of A. australis and mid intestine of A. dieffenbachii. Male and female Spirocamallanus sp. established in the mid intestine, but as female worms grew they attached more anteriorly and thus maintained the mid body in the mid intestine, prevented the tail end entering the rectum, and maintained the vulvae close to male worms. Cucullanus sp. was most often found in the mid intestine, but occurred throughout the intestine, possibly because of migration with food. Paraquimperia and Spirocamallanus extended their range with crowding; Cucullanus increased in density in the mid intestine. Posteriad movement, with or without subsequent evacuation, was a general feature of all species in both hosts, held live or examined after death. Chilling and freezing slowed or arrested loss from dead hosts. Larger worms (Spirocamallanus sp.) moved and were lost more rapidly than small worms (Paraquimperia sp.); worm loss was more rapid from A. dieffenbachii than from A. australis.  相似文献   

贵州关岭生物群盘江鱼龙体内胃融物研究     

程龙  陈孝红 《中国地质》2007,34(1):61-65

本文主要描述了关岭生物群中一美丽盘江鱼龙标本（YIGM V30016）-Panjiansaurus epicharis Chen＆Cheng体内的胃融物。其组成物质为微晶含有机质胶磷质生物碎屑灰岩。其中生物碎屑主要为较小的鱼类骨碎片．其次含有少量的双壳类外壳，没有胃石。通过分析胃融物的成分，比较牙齿类型和身体特征等，认为盘江鱼龙主要以小型鱼类和双壳类为食，并不需胃石帮助消化食物。  相似文献   

Sandy seepage faces as bioactive nitrate reactors: Biogeochemistry,microbial ecology and metagenomics     

《地学前缘(英文版)》2023,14(3):101529

Subterranean estuaries are highly dynamic in processing dissolved inorganic nitrogen (DIN). Here we investigate DIN turnover in surface sediments (0–20 cm depth) at the higher, medium and lower intertidal of a seepage face, i.e., the outer “mouth” of the subterranean estuary, during four consecutive seasons in Sanggou Bay, China. Throughout the studied period, ammonium (NH₄⁺) and nitrite (NO₂^?) concentrations in the sampled porewaters did not vary significantly with depth or season. In contrast, peaks in porewater nitrate (NO₃^?) concentration and decreases in δ¹⁵N-NO₃^? and δ¹⁸O-NO₃^? were observed in the 15–20 cm depth (bottom) sediment, particularly during summer and autumn. Coupled with NO₃^? production, the sediment total nitrogen was also markedly peaking in the bottom layer of the studied seepage face. Together with abundant heterotrophic microbes in the sediment, this NO₃^? accumulation was linked to a reaction chain including organic matter decomposition, ammonification and nitrification. During winter, porewater enrichment in total nitrogen occurred closer to the surface of the seepage face but triggered also active NO₃^? production. This pattern reinforced the importance of pelagic organic matter supply on NO₃^? production. In the shallower depths of the seepage face (<12 cm), active net NO₃^? removal occurred except in winter. The isotopic fractionation (δ¹⁵N-NO₃^? and δ¹⁸O-NO₃^?) and metagenomic results revealed denitrification as the main pathway for NO₃^? reduction. Biological assimilation from benthic primary producers may also consume a fraction of NO₃^? at the sediment water interface. Both NO₃^? production and removal significantly varied in magnitude with season (?13.6 to 6.2 nmol cm^?3 h^?1). Substrate supply was the key driver for nitrate cycling, as evidenced by the high NO₃^? production rate in spring by comparison to autumn. The highest NO₃^? turnover rates were found in summer, suggesting the combined influence of advection rates and sediment microbiota composition. In spite of active removal (peak NO₃^? removal capability: 61%), a significant amount of NO₃^? was still transported from the seepage face into the bay waters. The magnitude of NO₃^? fluxes ranged from 312 to 476 kg N d^?1, accounting for approximately 15% of the total exogenous NO₃^? loading into the bay. NO₃^? isotopic fingerprint revealed chemical fertilizer as the main source of terrestrial NO₃^? in SGD, highlighting the importance of land use to coastal system nitrogen budgets.  相似文献   

Biogeography, Substrate Preference, and Feeding Types of North Adriatic Intertidal Collembola   总被引：1，自引：0，他引：1  

Erhard Christian 《Marine Ecology》1989,10(1):79-93

Abstract. A survey of North Adriatic intertidal Collembola is given, including the first records of Friesea acuminata, Archisotoma interstitialis, Entomobrya dollfusi , and Pseudosinella hauseri. Granulometric and biococnological analyses of culittoral loose sediments allowed determination of the animals' substrate preference. The limitation to cuhaline habitats is tested by comparison with mixohaline shores nearby. Life-form typology is applied to elucidate the largely unknown relations of intertidal Collembola to the sediment surface or superficial strata. The different modes of nutrition are distinguished by mouthparts and by gut content analyses.  相似文献   

藻蓝蛋白对四氯化碳诱导的大鼠肝纤维化及肠道微生物的影响     

翟诗翔  李文军  李莉莉  王莉  秦松 《海洋科学》2021,45(7):103-109

为开发藻类活性物质的药用价值,探究了藻蓝蛋白（phycocyanin,PC）对四氯化碳（CCl₄）诱导的大鼠肝纤维化的影响。试验中将大鼠随机分为3组,分别为对照组、肝纤维化组、CCl₄+PC干预组。利用CCl₄腹腔注射诱导肝损伤模型,在干预后,通过RT-PCR技术检测了大鼠肝脏中纤维化标志物I型胶原蛋白（collagen type I,Co-I）和α-平滑肌肌动蛋白（alpha-smooth muscle actin,α-SMA）的表达情况,通过16S rRNA高通量测序技术检测了干预后大鼠肠道微生物的组成和结构。RT-PCR结果显示PC干预显著降低了CCl₄诱导的大鼠肝脏中纤维化标志物α-SMA和Co-I的表达。CCl₄诱导使大鼠肠道菌群发生了紊乱,显著降低了具有抗炎活性的益生菌Bacteroides、Blautia、Parabacteroides的丰度,PC干预显著增加了具有抗炎活性的益生菌Blautia的丰度。结果表明PC能够改善CCl₄引起的肠道菌群紊乱,这种改善可能有助于缓解CCl₄导致的肝纤维化。  相似文献   

RECENT ADVANCES IN GEOLOGICAL RESEARCH IN PARTS OF LESSER AND TETHYS HIMALAYA OF INDIA, SOUTH OF TIBETAN PLATEAU (KUMAON, GARHWAL AND ARUNACHAL PRADESH)     

Vinod C. Tewari 《地学前缘》2000,(Z1)

RECENT ADVANCES IN GEOLOGICAL RESEARCH IN PARTS OF LESSER AND TETHYS HIMALAYA OF INDIA, SOUTH OF TIBETAN PLATEAU (KUMAON, GARHWAL AND ARUNACHAL PRADESH)  相似文献   

中国对虾成虾肠道微生物区系   总被引：8，自引：0，他引：8  

王祥红  李会荣  张晓华  李筠  纪伟尚  徐怀恕 《中国海洋大学学报(自然科学版)》2000,30(3):493-498

对野生健康中国对虾成虾肠道微生物区系进行了研究.从其肠道中分离出47株菌,它们分别属于弧菌属、发光杆菌属、不动杆菌属、假单胞菌属、黄杆菌属、气单胞菌属、屈挠杆菌属和色杆菌属8个属.其中弧菌属和发光杆菌属在整个肠道中为优势菌属,不动杆菌属和假单胞菌属为次优势菌属,黄杆菌属、气单胞菌属、屈挠杆菌属和色杆菌属为非优势菌属.在对虾的整个肠道中,前肠和中肠的优势菌属为弧菌属,而后肠的优势菌属为发光杆菌属.在弧菌属中溶藻胶弧菌、漂浮弧菌和坎贝氏弧菌为优势菌,哈唯氏弧菌为非优势菌.前肠、中肠和后肠的菌量分别为1.3×105、2.8×105和1.1×104cfu/虾体.  相似文献   

人参醇提物及沉淀对小鼠肠道菌群的影响          下载免费PDF全文

李勇敏  张尚华  罗吉 《应用海洋学学报》2020,36(12):147

目的：探讨人参醇提物及其沉淀对小鼠肠道菌群的影响。方法：利用环磷酰胺制备免疫低下小鼠模型,以人参水提物为对照,观察人参醇提物及其沉淀对小鼠肠道菌群的影响;肠道菌群数据采用Flash 1.2.11、Qiime 1.9.1、Mothur 1.30.2及PICRUSt 1.1.0等软件分析。结果：通过样本多样性指数分析,发现小鼠十二指肠、结肠、直肠所在部位肠道菌群结构差异具有统计学意义（P＜0.05或P＜0.01）。群落组成分析得知,小鼠肠道菌群差异较大的是Firmicutes(厚壁菌门),Bacteroides(拟杆菌门),Proteobacteria (变形菌门)与 Epsilonbacteraeota,Actinobacteria(放线菌门),Tenericutes(柔壁菌门)等。物种差异分析显示,免疫低下模型小鼠直肠部位的Epsilonbacteraeota数量显著增多(P=0.02),表明菌群失调;人参能调节肠道菌Epsilonbacteraeota失衡,其功效由大到小依次为人参水提物、醇提物及其沉淀。功能预测显示,肠道菌群结构改变,其对应的基因功能信息也改变,免疫低下模型小鼠直肠菌群结构与数量改变,引起RNA processing and modification, Chromatin structure and dynamics, Energy production and conversion 等方面基因改变。结论：免疫低下小鼠肠道菌群结构与功能改变,人参的不同提取物及其沉淀对小鼠肠道菌群有一定的影响。  相似文献   

基于高通量测序技术解析鲣鱼(Katsuwonus pelamis)鱼油和鱼白调控肠道菌群结构作用     

李菁菁  张旨轩  王子言  刘岩  霍春恒  石秋月  陈菊  韩姣姣  苏秀榕 《海洋与湖沼》2021,52(3):738-745

本研究利用高通量测序技术分析小鼠喂食鲣鱼(Katsuwonus pelamis)鱼油和鱼白酶解液后肠道微生物的多样性、群落组成以及结构的变化,探讨高蛋白、高脂肪饮食对人类健康的影响。研究结果显示:喂食鱼油组小鼠的肠道微生物丰富且多样。在门水平上,对照组和鱼油组的优势菌门为拟杆菌门(Bacteroidetes);鱼白组的优势菌门为厚壁菌门(Firmicutes)。在科水平上,对照组和鱼油组中的优势菌科为Muribaculaceae;鱼白组中的优势菌科为毛螺菌科(Lachnospiraceae)。在属水平上,对照组和鱼油组中的优势菌属为Muribaculum;鱼白组中的优势菌为Lachnoclostridium;对照组、鱼油组和鱼白组小鼠的肠道微生物群落中瘤胃球菌属(Ruminococcus)和拟杆菌属(Bacteroides)等丰度较高。在种水平上,对照组和鱼油组中的优势菌为Muribaculum intestinale;鱼白组中的优势菌为解糖梭菌(Clostridium saccharolyticum)。研究结果证明鲣鱼鱼油和鱼白可以调节菌群结构和组成,增加肠道有益菌,减少病原菌的丰度等。  相似文献   

Bacterial diversity of gut content in sea cucumber (Apostichopus japonicus) and its habitat surface sediment   总被引：1，自引：0，他引：1  

GAO Fei  TAN Jie  SUN Huiling  and YAN Jingping 《中国海洋大学学报(英文版)》2014,13(2):303-310

This study investigated the bacterial diversity of gut content of sea cucumber(Apostichopus japonicus) and its habitat surface sediment in a bottom enhancement area using PCR-based denaturing gradient gel electrophoresis(DGGE) technique. Bacterial diversity evaluation showed that the value of the Shannon-Wiener index of gut content in different intestinal segments of A. japonicus varied between 2.88 and 3.00, lower than that of the surrounding sediment(3.23). Phylogenetic analysis showed that bacterial phylotypes in gut content and the surrounding sediment of A. japonicus were closely related to Proteobacteria includingγ-, α-, δ-and ε-proteobacteria, Bacteroidetes, Firmicute, and Actinobacteria, of which γ-proteobacteria were predominant. These results suggested that the sea cucumber A. japonicus was capable of feeding selectively, and PCR-DGGE was applicable for characterizing the bacterial community composition in gut content and the surrounding sediment of sea cucumber. Further investigation targeting longer 16S rDNA gene fragments and/or functional genes was recommended for obtaining more information of the diversity and function of bacterial community in the gut content of sea cucumber.  相似文献