Survival of Rhipicephalus appendiculatus (Acarina: Ixodidae) and persistence of Theileria parva (Apicomplexa: Theileriidae) in the field

Newson R. M., Chiera J. W., Young A. S., Dolan T. T., Cunningham M. P. and Radley D. D. 1984: Survival of Rhipicephalus appendiculatus (Acarina: Ixodidae) and persistence of Theileria parva (Apicomplexa: Theileriidae) in the field. International Journal for Parasitology14; 483–489. Two paddocks with populations of the African brown ear tick (Rhipicephalus appendicuiatus), one of which carried virulent Theileria parva (the causative organism of East Coast fever [ECF] of cattle), were left unstocked for periods of 338 and 354 days. Groups of 1–3, ECF-susceptible cattle were then introduced eight times during the following year to assess the tick and disease challenge, The ticks were also monitored continuously on the ground. The test cattle developed fatal ECF from adult ticks which had fasted for up to 554 days. A non-pathogenic, antigenicaliy distinct, Theileria species was also detected which was still transmitted by adult ticks after 600 days. The mean survival time of unfed larvae was 175 days (max. 240 days); unfed nymphs 270 and 450 (max. 540 days); unfed adults 420 days (max. 730 days), with females in a clear majority after 270 days.     

中国沿海海鞘的物种多样性

至今,中国海已经记录了66种海鞘。其中,渤海有5种,黄海21种,东海24种,南海53种。种类分布从北往南逐渐递增,柄瘤海鞘在黄海、渤海数量很大(8100个/m²),但往南分布,未发现超过罗源湾。皱瘤海鞘在南海数量很大(2225个/m²),往北也未发现超过罗源湾。玻璃海鞘和乳突皮海鞘在全国沿海都有分布。     

Marine biotopes of Askar coastal area,east of Bahrain

The scope of the present work has covered the area located at the east coast of Bahrain along the Askar coast associated with depth mostly < 10 m, extending for approximately 5Km. This coastal area is subjected to several sources of industrial and domestic pollution. The marine survey was conducted in May 2018 within an area of ～5.27 km² covering the intertidal and subtidal zones. A drop-down video camera (DDV) was used within an equidistant station grid spaced by 300 m and entailed 69 stations. SCUBA diving was performed at eight locations representing different biotopes for qualitative and quantitative analysis based on epi-benthic flora and fauna. Five biotopes were identified representing silty sand, silty sand with seagrass, mud, rock with sand veneer and macroalgae. A lack of conspicuous flora and fauna characterized most of the sites investigated. The seagrass habitat was found to be of less cover across the study area represented by patchy forms (<1%). The high concentration of alluvium discharged by the sand wash plant heavily impacted the water clarity, where fine particles were driven by currents during the ebb cycle toward the Askar coast. The DDV survey showed that most of the bottom layers are turbid and numerous dead bivalve shells of Pinctada sp. were observed. The current monitoring program needs to be rescheduled to cover further locations to minimize the vulnerability of traditional fisheries.     

Effect of starvation on the nutritional condition of early zoea larvae of the red squat lobster Pleuroncodes monodon (Decapoda,Munididae)

Abstract

One of the key factors affecting larval survival is food availability. This study investigated the influence of starvation on the nutritional condition of zoea I larvae of Pleuroncodes monodon. Experimental treatments with differential periods of starvation and subsequent feeding (point of no return: PNR) in addition to treatments with differential periods of feeding and subsequent starvation (point of reserve saturation: PRS) were used to quantify larval survival and the occurrence of lipid droplets in the hepatopancreas. Larval survival differed significantly depending on the starvation and feeding treatment administered. A high percentage of survival was found for the starvation treatment until day 1 (S1-PNR), for the feeding treatment until day 4 (F4-PRS), and for the continuously fed control groups (FC). Survival was minimal for the starvation treatment lasting until day 7 (S7-PNR) and for the continuously starved control groups (SC). In turn, similar tendencies were observed in the utilization of energy reserves; the lipid droplets significantly decreased throughout the PNR treatment, while the presence of lipid droplets gradually increased during the PRS treatment. All these larval condition parameters can be used in fishery models of population dynamics, which estimate the nutritional status of the offspring and their effects on survival.     

Expenditures and Effort Associated With Recovery of Breeding Atlantic Coast Piping Plovers

ABSTRACT We calculated expenditures and hours of staff and volunteer time dedicated to monitoring and managing the United States breeding population of Atlantic Coast piping plovers (Charadrius melodus) in 1993 and 2002 and considered implications for recovery of this management-dependent species. In 2002, 73 federal, state, and local governmental agencies and private organizations played key roles in conservation efforts at 281 piping plover breeding sites. Total inflation-adjusted estimated expenditures increased by 51% between 1993 and 2002, from US$2.28 million to $3.44 million, but annual per-pair expenditures declined 4% from $2,459 to $2,350, and hours of paid-staff effort were similar (93 hr/pair in 1993, 95 hr in 2002). Expenditures for on-site monitoring and management were greater than for 6 other categories of expenses in both years and increased from 42% to 59% of total costs between 1993 and 2002. Staff time and expenditures were higher at sites where more labor-intensive efforts to protect plovers from recreation and other human use were necessitated by greater human accessibility. Total expenditures in 2002 were modest compared to those for some other threatened and endangered species and to costs of large beach-stabilization projects. Our results provide a baseline for estimating future costs of piping plover protection, including development and implementation of the long-term management agreements that will be required to remove this species from United States Endangered Species Act protection. Impediments to reducing costs for Atlantic Coast piping plovers are the species’ widespread distribution at low densities and the unrelenting threats posed by human activities and predators. Modest economies of scale may be achieved through arrangements for management and monitoring that span multiple landowners and include other at-risk beach species.     

The Legal Status of the Russian Baselines in the Arctic

The validity under international law of the straight baselines the Soviet Union established in the Arctic and that Russia maintains are examined. For the purpose of comparison with the Russian regime, the issues surrounding the international regimes of baselines are analyzed. The results are then compared, as well as the practice of the main opponent with navigational interests in the area, the United States. It is found that while many of the enclosures fail the traditional criteria for establishing straight baselines and basepoints as well as the traditional criteria for enclosing bays, due to the moderate degree of deviation, largely unopposed by other states, the Russian practice cannot be said to be inconsistent with international law. At the same time, although the waters enclosed can be claimed as internal waters under the Anglo-Norwegian Fisheries Case , Article 5(1) of the 1958 Convention on the Territorial Sea and the Contiguous Zone (TSC), and Article 8(1) of the 1982 United Nations Convention on the Law of the Sea (1982 Convention), they are still subject to TSC Article 5(2) and 1982 Convention Article 8(2). If the waters enclosed thus could not previously have been considered as internal waters, the right of innocent passage exists.     

美国长期生态研究计划三十年:特点、效果与启示——以弗吉尼亚海岸带保护区为例

为观测和理解长时间与大范围尺度的生态变化,美国自然科学基金会于1980年启动了长期生态研究计划(LTER),30年来在站点建设、科学研究和社会服务等方面取得了巨大成就.本文将美国LTER的成功经验归纳为5个特点,即:研究网络、研究主题和数据兼容的系统性,项目时间与研究尺度的长期性,资金来源与研究内容的灵活性,国际、人文、方法与机构合作方面的拓展性,数据和教育的共享性;并以弗吉尼亚海岸保护区(VCR)为案例展示其实施效果.在此基础上提出对我国长期生态研究的建议,包括加强组织建设,建立完整网络并增强站际合作,重视数据的质量、管理和分享,增强多学科研究,扩大公共影响等.     

Phylogeographical pattern of Mazocraeoides gonialosae (Monogenea, Mazocraeidae) on the dotted gizzard shad, Konosirus punctatus, along the coast of China

In the present study, we examined the phylogeographical pattern of the monogenean, Mazocraeoides gonialosae, which parasitises the dotted gizzard shad (Konosirus punctatus) along the coast of China. Fragments of 756 bp of the mitochondrial cytochrome c oxidase subunit I gene were sequenced for 147 individuals from seven localities along the coast of China. Phylogenetic analysis revealed no significant genealogical clades of samples corresponding to sampling localities. Analyses of molecular variance and pairwise F_ST suggested a high rate of gene flow and the lack of a predictable genetic structure between different populations of this parasite. Both neutrality tests and mismatch distribution analyses indicated a recent population expansion in M. gonialosae after the last glacial maximum. Gradually decreasing genetic diversity in more northerly populations implied a historical south-to-north expansion of this parasite. Dispersal of eggs and larvae with ocean currents was considered to be associated with the genetic homogeneity of this species. The limited time to accumulate genetic variation after the last glacial maximum may also account in part for the lack of phylogeographical structure in the studied region.     

Beyond the tropics: forest structure in a temperate forest mapped plot

Question: How do the diversity, size structure, and spatial pattern of woody species in a temperate (Mediterranean climate) forest compare to temperate and tropical forests? Location: Mixed evergreen coastal forest in the Santa Cruz Mountains, California, USA. Methods: We mapped, tagged, identified, and measured all woody stems (≥1 cm diameter) in a 6‐ha forest plot, following Center for Tropical Forest Science protocols. We compared patterns to those found in 14 tropical and 12 temperate forest plots. Results: The forest is dominated by Douglas‐fir (Pseudotsuga menziesii) and three species of Fagaceae (Quercus agrifolia, Q. parvula var. shrevei, and Lithocarpus densiflorus), and includes 31 woody species and 8180 individuals. Much of the diversity was in small‐diameter shrubs, treelets, and vines that have not been included in most other temperate forest plots because stems <5‐cm diameter had been excluded from study. The density of woody stems (1363 stems ha^?1) was lower than that in all but one tropical plot. The density of large trees (diameter ≥30 cm) and basal area were higher than in any tropical plot. Stem density and basal area were similar to most other temperate plots, but were less than in low‐diversity conifer forests. Rare species were strongly aggregated, with the degree of aggregation decreasing with abundance so that the most common species were significantly more regular than random. Conclusions: The patterns raise questions about differences in structure and dynamics between tropical and temperate forests; these need to be confirmed with additional temperate zone mapped plots that include small‐diameter individuals.     

Assessment of saltwater intrusion impact on gas exchange behavior of Louisiana Gulf Coast wetland species

A review of gas exchange responses of wetland plants to salinity is presented for several species representative of different wetland habitats extending along water level and salinity gradients in the Louisiana Gulf Coast, U.S.A. The information was synthesized from earlier plant physiological response studies. Vegetation examined represent a broad range of sensitivity to salt, including brackish marsh, freshwater marsh, and bottomland tree species. Changes in stomatal conductance and carbon assimilation rates are common responses of wetland plants to short-term and long-term exposure to salinity. The combination of anaerobiosis and salinity apparently causes substantial reductions in stomatal conductance and carbon assimilation. Exposure to salt concentrations greater than 170 mol m^–3 (10 ppt) caused leaf death in plants representing freshwater habitats. Data presented suggest that saltwater intrusion and/or brine discharges into wetland areas, a common problem facing the Louisiana Gulf Coast, can adversely affect a host of wetland species. The impact will likely lead to weaker plants with reduced survival rates and decreased productivity, thus creating the potential for long-term habitat changes.