十溴联苯醚(BDE-209)胁迫对褶皱臂尾轮虫(Brachionus plicatilis)摄食与选食的影响

实验生态条件下研究十溴联苯醚(BDE-209)的急性毒性胁迫对褶皱臂尾轮虫(Branchionus plicatilis)运动行为与摄食行为的影响,探讨可用以表征胁迫-响应的生物标志物。结果表明:(1)BDE-209胁迫24h显著性增加了褶皱臂尾轮虫的运动抑制率,由此得到24h半数有效抑制浓度(24h-EC_(50))为9.084mg/L,但未达到半数致死作用;(2)当分别以四种海洋微藻:小球藻(Chlorella vulgaris)、青岛大扁藻(Platymonas helgolandica)、等鞭金藻8701(Isochrysis galbana)和小新月菱形藻(Cylindrotheca closterium)为单一饵料来源时,褶皱臂尾轮虫对四种饵料单胞藻的滤水率(F)和摄食率(G)均随着胁迫时间和胁迫浓度的增加而不断下降,呈现出明显的浓度依赖性,说明BDE-209胁迫能显著抑制褶皱臂尾轮虫的摄食作用。(3)将其中三种微藻等生物量混合投喂时,褶皱臂尾轮虫对三种微藻的滤水率和摄食率与单一饵料投喂条件相比均发生变化,且对各种微藻的选食率(Sr)和摄食总生物量均随着胁迫时间和浓度的增加呈下降趋势,选择性指数(Si)发生变化,对小球藻的摄食选择性最高。滤水率的变化较其它指标更敏感,可用以指示浮游动物在个体水平上响应外源环境变化的标志物。结果表明,BDE-209胁迫能有效改变褶皱臂尾轮虫的摄食与选食行为,且其最适宜的饵料是小球藻。     

Application of DNA metabarcoding to characterize the diet of the moon jellyfish Aurelia coerulea polyps and ephyrae

Dietary studies of polyps and ephyrae are important to understand the formation and magnitude of jellyfish blooms and provide important insights into the marine food web. However, the diet of polyps and ephyrae in situ is largely unknown. Here, prey species of the polyps and ephyrae of the moon jellyfish Aurelia coerulea in situ were identified using high-throughput DNA sequencing techniques. The results show that A. coerulea polyps and ephyrae consume a variety of prey items. The polyps consume both planktonic and benthic prey, including hydromedusae, copepods, ciliates, polychaetes, stauromedusae, and phytoplankton. A. coerulea ephyrae mainly feed on copepods and hydromedusae. Gelatinous zooplankton, including Rathkea octopunctata and Sarsia tubulosa, were frequently found as part of the diet of A. coerulea polyps and ephyrae. The utilization of high-throughput sequencing technique is a useful tool for studying the diet of polyps and ephyrae in the field, complementing the traditional techniques towards a better understanding of the complex role of gelatinous animals in marine ecosystems.     

Mixing and transport near the shallow-crested Rumble III seamount and the implications for plankton distribution

Vessel-based observations of water column structure and flow near a shallow-crested seamount are used to quantify the physical disturbance induced by that seamount. The implications of this disturbance on the ‘feeding hole’ hypothesis are then examined based on data from moored thermistors and acoustic current profilers, as well as vessel-based acoustic sounding-derived biomass estimates, currents, and conductivity-temperature-depth profiles from a 55 km square grid of stations around the crest. Mean currents in the region of 0.2 m s^?1 are comparable to observations from surface drifters whereas the semidiurnal tidal flow amplitude was one third of this. Thorpe Scale-based estimates of energy dissipation rate were in the range 10^?9 to 2.10^?8 W kg^?1 and vertical diffusivities K_z were in the range 10^?4 to 10^?3 m² s^?1. Turbulence levels were higher upstream of the seamount–likely due to the influence of nearby seamounts Rumble IV and V. There was no evidence of a Taylor Cap in the Rumble III velocity field. The sounder data provide some evidence of a feeding hole and analysis based on diffusivities suggests that this might persist downstream of the seamount for as much as 7 days.     

Diel changes in the abundance and size composition of invertebrate drift in five rivers in South Island,New Zealand

Drift was collected over 24‐h periods in five rivers in South Island, New Zealand, to determine whether diel periodicity was consistent across a range of river types, and whether the pattern was similar for different life stages/sizes of selected taxa. Total drift density (numbers per 100 m³ ) of aquatic invertebrates was greater at night than during the day in all rivers; peak abundance occurred shortly after sunset in clear water rivers and shortly before sunrise in a turbid, glacier‐fed river. Densities of drifting Deleatidium spp., Nesameletus spp. (both Ephemeroptera), Aoteapsyche spp., and Hydrobiosidae (both Trichoptera), were generally greater at night than during the day. However, the timing of peak abundance in the drift for other common taxa varied between rivers. Larger Deleatidium spp. larvae (> 1.00 mm head width) were more common in the drift at night than during the day in all rivers. However, this was not apparent for Aoteapsyche spp. and Hydrobiosidae, for which diel differences in the size of drifting animals were not consistent even within the same river. The propensity for some aquatic invertebrates to drift at night may influence fish feeding behaviour, particularly with respect to the timing of feeding and the species or life history stages of their prey.     

Assessment of toxicity of dissolved and microencapsulated biocides for control of the Golden Mussel Limnoperna fortunei

Biological invasions currently pose major threats to ecosystems worldwide. Invasive bivalves such as the Golden Mussel Limnoperna fortunei can act as ‘environmental engineers’, altering biogeochemistry, reducing biodiversity, and literally changing the landscape of aquatic environments. The risk that this mussel will invade the Amazon basin is a great concern for environmental authorities, especially because no efficient control methods presently exist. In this study, we tested new microencapsulated chemicals, along with the traditional dissolved chlorine and KCl, as alternatives to control L. fortunei infestation in industrial and water supply plants along rivers. Because these bivalves can close their valves when they sense toxic substances in the water, microencapsulation has improved the effectiveness of the chemicals in controlling L. fortunei, reducing variation in the application and increasing toxicity compared to dissolved chemicals. Microencapsulation should be seriously considered as an alternative to replace hazardous chlorine.     

Pycnogonida of the snares islands∗

Eight species of Pycnogonida collected by University of Canterbury Expeditions and the New Zealand Oceanographic Institute are recorded from the Snares Islands, which lie at 48° 05’ S, 166° 20’ E, 60 miles SW of South Cape, Stewart Island. The following species are recorded: Pallenopsis obliqua (Thomson, 1884), Cheilopallene trappa n.sp., Ammothea magniceps Thomson, 1884, Achelia dohrni (Thomson, 1884), Tanystylum cavidorsum Stock, 1957, Ascorhynchus insularum n.sp., Austrodecus minutum n.sp. and Austrodecus enzoi n.sp.     

In‐stream habitat suitability criteria for feeding inanga (Galaxias maculatus)

Inanga (Galaxias maculatus Jenyns) are the basis of an important recreational and commercial freshwater fishery that has declined over the past 100 years, probably because of habitat degradation in developed areas. Maintenance of suitable stream flows for inanga is one means of protecting the fishery. Observations of habitat use by drift‐feeding inanga were made in three streams. Most feeding inanga were stationary in the current taking food items from the drift and sometimes from the surface. Drift‐feeding locations were related to current patterns and water velocity, with inanga feeding at locations where the current concentrated food, and where water velocities were sufficiently low to allow the fish to hold position. The mean feeding velocity did not vary significantly between streams, although the range of velocities used did. Optimum feeding velocities were 0.03–0.07 m s^‐1, and were comparable with brown trout (Salmo trutta) feeding velocities, when adjusted for the differences in fish size. Depth use was very different between streams and this was attributed to the variation in available habitat. Depths greater than 0.3 m were optimum, with some use of depths between 0.1 and 0.3 m. It is suggested that inanga suitability criteria are dictated by biological factors, such as swimming ability and bio‐energetic requirements, rather than the river the fish is living in and that it is necessary to collect habitat use and availability data in a wide range of stream types to define optimal habitat and suitability criteria for generalised application.     

Computer system for processing copious biological data,IBM 1130 fortran format

An IBM 1130 computer program system for preliminary processing of copious biological data is described. Its advantage ia comparison with the more usual manual calculation methods is the speed at which data can be handled, sorted, and analysed. Only a small computer need be available to the user.     

Algivory in hawksbill turtles: Eretmochelys imbricata food selection within a foraging area on the Northern Great Barrier Reef

This paper describes the food selection of hawksbill turtles, Eretmochelys imbricata, using reefs of the Far Northern Section of the Great Barrier Reef Marine Park (nGBR) during 2006 and 2007. A total of 467 gastric lavage and 71 buccal cavity ingesta items were collected from 120 individual E. imbricata, comprising adult female and immature turtles of both sexes. Nineteen E. imbricata that were captured in 2006 were recaptured and sampled again in 2007. Within the total pooled buccal and lavage sample (n = 538), the occurrence of food items was dominated (72.7%) by only three algal taxonomic divisions: Rhodophyta (red algae; 53.7%, n = 289); Chlorophyta (green algae; 11.0%, n = 59) and algae from the division of Phaeophyceae (brown algae; 8.0%, n = 43). The remaining total (buccal and lavage) ingesta sample comprised sponges (10.4%, n = 56), soft corals and a wide variety of possibly nutritionally important invertebrate species (12.6%, n = 68), and a small percentage (5.4%, n = 22) of inorganic material. Generally, E. imbricata were considered to be primarily a sponge‐feeding specialist and secondarily an omnivorous species; within coral reef habitats and in various parts of the world this is the case. However, this study has shown that E. imbricata found foraging on reefs of the nGBR are primarily algivorous and secondarily omnivorous. A feeding strategy that relies on a predominantly algal diet may infer important benefits to the species if the impacts of climate change and ocean acidification inhibit coral growth, while promoting algal density and distribution within the Great Barrier Reef ecosystem.     

煤矿送料孔、通风孔及救援孔钻进技术

介绍了煤矿送料孔、通风孔及救援孔等工程钻孔的钻进工艺及所用器具,并通过中国神华集团的施工实例对此类工程钻孔的前导钻进及扩孔钻进技术进行了较为详细的探讨。