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21.
江西省都昌候鸟省级自然保护区作为鄱阳湖流域内占地面积最大的自然保护区,承担着保护世界性和国家重点保护濒危越冬候鸟资源等重要责任。探究都昌候鸟自然保护区浮游甲壳动物群落结构及其主要影响因子,可为都昌保护区内鸟类栖息地的生境保护与动态评估提供科学依据。2019—2021年1、4、7和10月对都昌保护区内4个区域的浮游甲壳动物的密度、生物量和水环境因子进行采样调查,运用多样性指数、Pearson相关性和冗余分析(RDA)等对都昌保护区水质情况以及浮游甲壳动物与水环境因子和叶绿素a之间的关系进行解析。结果显示,调查期间共鉴定出浮游甲壳动物31种,其中枝角类(20种)和桡足类(11种)。都昌保护区浮游甲壳动物年均密度213.81 ind./L,年均生物量为1.51mg/L。都昌保护区浮游甲壳动物群落结构时空变化较大,季节上,夏季或秋季浮游甲壳动物的生物量达到峰值,冬季浮游甲壳动物种类最少;空间上南矶一般区(D4)浮游甲壳动物密度和生物量较大,其次是撮箕湖一般区(D3),小矶山核心区(D1)和三山核心区(D2)差异较少。根据多样性指数和均匀度指数分析都昌保护区水质情况,结果表现为撮箕湖一般区(D3... 相似文献
22.
中华窄腹剑水蚤是中国河流中发现的土著种类,具有较强的生态入侵能力,通过从西江抽水进入大镜山水库,成为该水库的优势浮游甲壳类,通过2005-2006两年的采样监测,初步分析了该水库中中华窄腹剑水蚤的种群特征及其对浮游甲壳类的群落动态和结构的影响.两年共检出浮游甲壳类13种,其中,桡足类4科7属9种,枝角类3科4属4种,中华窄腹剑水蚤是水库的优势种,两年浮游甲壳类丰度的范围是3.82-364.85ind/L,峰值出现在春季,两年变化趋势相似,水库浮游甲壳类的体长分布范围为0.07-1.25mm,主要由小个体的类群(体长在0.07-0.4mm之间)组成,个体较大(大于0.5mm)的枝角类和桡足类数量很低,中华窄腹剑水蚤和其无节幼体的丰度占甲壳类总丰度的50%以上,其丰度的动态分布与浮游甲壳类的总体丰度的动态分布一致,中华窄腹剑水蚤主要以三种形式(无节幼体Ⅰ期,桡足幼体后期和成体)存在于水体中,存活曲线呈Ⅲ型,无节幼体的丰度远高于后两者之和,该种类能成为水库优势种主要是由水库成度变化剧烈水环境特征和其自身的生态学特点决定的,中华窄腹剑水蚤丰度与叶绿素a浓度具有显著正相关性,与抽水入库量具有极显著的负相关性,作为一个生态入侵种类,中华窄腹剑水蚤降低水体中浮游甲壳类生物多样性,并替代了原来的土著优势种. 相似文献
23.
外源溶解性有机碳对抚仙湖甲壳类浮游动物碳源的贡献 总被引：2，自引：1，他引：1
外源溶解性有机碳(DOC)是湖泊碳库的重要组成部分,关于外源DOC对浮游动物的贡献及途径需要深入研究.本研究在抚仙湖受控实验中添加13C标记的葡萄糖,通过分析样品中浮游植物与浮游动物的种类、数量、磷脂脂肪酸生物标志物及其稳定同位素特征,研究外源DOC对湖泊甲壳类浮游动物碳源的贡献比例及其变化.结果表明:细菌、甲壳类浮游动物(象鼻溞)的δ~(13)C值在加入葡萄糖后分别从-16.28‰和-23.88‰快速增加到5408.25‰和1974.7‰,而藻类磷脂脂肪酸(C18∶2ω6)δ~(13)C值从-27.07‰增加到342.44‰,增长的幅度表明添加的葡萄糖首先被细菌和浮游动物快速利用,而藻类只利用了一小部分.同时细菌、颗粒性有机物(POM)和浮游动物的δ~(13)C值在第1 d急剧增加,细菌的δ~(13)C值远大于浮游动物和POM的δ~(13)C值,之后细菌和POM的δ~(13)C值开始下降,但浮游动物的δ~(13)C值却仍在缓慢增加,进一步表明了DOC进入湖泊后首先被细菌吸收利用,而细菌吸收DOC后通过自身代谢作用形成细胞颗粒,浮游甲壳类动物通过摄食细胞颗粒来获得外源DOC. 相似文献
24.
The study was to find out the effect of cadmium and mercury on levels of hemolymph glucose, crustacean hyperglycemic hormone (CHH) and hepatopancreas glycogen in the blue swimmer crab Portunus pelagicus. The experiments were performed in both intact and eyestalk ablated crabs. Quantification of CHH was done by the indirect ELISA with the aid of primary anti-Carcinus maenas-CHH antibody. Higher glucose concentration was observed on exposure to 8×10-6 of cadmium ((825.6±5.42) μg/mL) and 6×10-6 of mercury ((90.5±6.25) μg/mL) after 48 h and 24 h respectively. Higher level of hemolymph glucose was observed in eyestalk intact crabs on exposure to cadmium and mercury than eyestalk ablated crabs. Decrease in the levels of CHH was observed in both eyestalk intact and ablated crabs on heavy metal exposure. Decline of the hepatopancreas glycogen level was also witnessed with the exposure to heavy metal, which validated its utilization in the production of glucose. Thus this study brings to light, the variations in hemolymph glucose, CHH and hepatopancreas glycogen on heavy metal stress. These carbohydrate metabolites can be used as biomarkers in assessing heavy metal contamination in water bodies. 相似文献
25.
Mariano J. Albano Carlos Rumbold Ignacio L. Chiesa Guadalupe Vazquez Eduardo D. Spivak Sandra M. Obenat 《新西兰海洋与淡水研究杂志》2019,53(1):15-32
We report the occurrence of the invasive amphipod Monocorophium acherusicum in Mar del Plata port, Argentina, using morphological and molecular analysis and estimated mean abundance to detect monthly variations of this population. We compared M. acherusicum morphology with that of M. insidiosum and Crassicorophium bonelli, the two most similar locally occurring species, to establish the diagnostic characteristics for the correct identification of them; moreover, we provide some taxonomic notes about others corophiids regionally distributed. M. acherusicum were collected in a subtidal biofouling community and its mean abundance was maximum in summer. In the molecular analysis, the maximum-likelihood tree showed that specimens from Mar del Plata were clustered with M. acherusicum specimens from GenBank and Boldsystems. We support and confirm the species identity in Mar del Plata port using DNA barcoding and with taxonomic methods. 相似文献
26.
Francisca Arratia Pamela Olivares-Ferretti Alba García-Rodríguez Ricard Marcos 《新西兰海洋与淡水研究杂志》2019,53(3):460-469
Copper-based nanoparticles (NPs) are being widely used in different application fields and their health impacts to aquatic environments represent a current concern. Few studies are available about their comparative toxicity with their bulks and ions under natural exposition in aquatic organisms. Thus, the toxicity of Cu and CuO NPs and their microparticle and ionic forms was assayed in the acute immobilisation test of Daphnia magna by using freshwater media. Electronic microscopy, laser doppler velocimetry, and dynamic laser scattering methodologies were used to NPs characterisation. The results indicated that CuNPs and CuONPs were more toxic than their microparticles. Among NPs, CuNPs showed higher toxicity than CuONPs. Copper-based nanoparticles showed similar hydrodynamic particle size and were agglomerated in culture media, suggesting toxic-ionic release relationship and corroborated by the high toxicity induced by CuSO4. Additionally, water chemistry of natural freshwater used in the experiments also favoured the ion release of these NPs. 相似文献
27.
D. J. Jellyman 《新西兰海洋与淡水研究杂志》2013,47(2):193-209
Recruitment of glass‐eels into freshwater is in two distinct phases characterised by behavioural differences: an initial invasion from the sea, and an upstream migration. Catches made at night in the Makara Stream, Wellington (41° 13'S, 174° 43’ E) indicate that the invasion by both New Zealand species commences in July, with that of the long‐finned eel Anguilla dieffenbachii Gray finishing by November, and that of the short‐finned eel A. ausiralis schmidlii Phillipps by December. The length of post‐metamorphic sea‐life influences both morphology and behaviour of the glass‐eels. Differences in this period of sea‐life between early and late season glass‐eels explain the initial avoidance but later attraction of fresh water to the glass‐eels. Responses to fresh water also explain the preference for early season glass‐eels to invade on the flood tide and late season glass‐eels on the ebb tide. Neither the lunar cycle nor rainfall appear to be significant influences on invasion periodicity. 相似文献
28.
Brown trout (Salmo trutta) are known to have effects on multiple trophic levels in New Zealand streams, but their impacts on lower trophic levels are less well understood within lentic systems. We examined the effects of brown trout removal using rotenone on zooplankton and phytoplankton community composition in the Upper Karori Reservoir, New Zealand. Significant shifts were observed in zooplankton and phytoplankton composition following removal of brown trout from the reservoir. Shifts in zooplankton community composition did not occur immediately following trout removal (February), but instead followed the likely timing of galaxiid spawning (July). The removal of brown trout likely resulted in reduced predation pressure on galaxiids. A major change occurred in the zooplankton community with the dominance shifting from larger crustaceans to smaller rotifers, indicating an increased predation pressure from the larval native galaxiid. A delayed response in zooplankton community composition change indicates rotenone was not the direct cause of this. A major shift in phytoplankton community composition occurred immediately following trout removal. This was not consistent with the trophic cascade hypothesis of reduced grazing pressure from larger zooplankton due to increased galaxiid predation as a result of brown trout removal. 相似文献
29.
浮游动物死体是海洋沉降碳通量的重要组成部分,研究浮游动物死体对于准确评估特定海区生物泵碳通量具有十分重要的意义。为了解夏季南黄海浮游甲壳动物在自然海区的死亡情况,采用2019年7~8月在南黄海获取的浮游动物样品,使用中性红染色法分析了浮游甲壳动物死体的平面分布及其受控环境因素。结果表明,夏季南黄海浮游甲壳动物平均丰度为(1 378.3±929.84) ind./m3,其死体比例在5.0%~68.8%之间,平均为33.3%±16.6%。桡足类是浮游甲壳动物的主要类群,平均丰度为(1 202.9±937.4) ind./m3,死体比例在3.6%~69.7%之间,平均为38.6%±17.0%,与全球海域浮游桡足类的平均死体比例相当。不同浮游甲壳动物优势种的死体比例存在差异。其中,拟长腹剑水蚤(Oithona similis)死体比例最高(62.0%),鸟喙尖头溞(Penilia avirostris)最低(17.9%)。与环境因子的相关性分析结果表明,海水温度和盐度是影响夏季南黄海浮游甲壳动物死体比例的主要影响因子。小拟哲水蚤(Paracalanus parvus)死体比例和表层温度显著正相关,拟长腹剑水蚤和近缘大眼剑水蚤(Corycaeus affinis)的死体比例与表底温差具有显著的正相关;而表层盐度与克氏纺锤水蚤(Acartia clausi)的死体比例存在正相关关系。该研究结果可为深入认识南黄海海洋生态动力学过程和海洋碳通量等相关研究提供重要的参考资料。 相似文献
30.
The Haustorius canadensis population at Long Sands beach in southern Maine was studied over a period of 45 months. The length-weight relationship was examined over 24 months; it showed no difference due to either sex or month. Caloric content of the population displayed a seasonal cycle around a mean of 18·381 KJ gm−1 dry weight, peaking in mid to late summer. The increment summation, instantaneous growth, removal summation and size-frequency methods of calculating production were used and the results compared. The increment summation and instantaneous growth methods provided the best estimates of production, averaging 98·1 gm m−1 y−1 and 100·2 gm m−1 y−1, respectively. The annual production to mean biomass ratio averaged 1·48. The population exhibited strong peaks of production; the four summer months accounting for 4·65 times the production during the remainder of the year. Most of the production was due to one-year-old individuals. 相似文献