Some impacts of low and medium head weirs on downstream fish movement in the Murray–Darling Basin in southeastern Australia

Abstract –  This article reports on the findings of a study undertaken within the Murray-Darling River Basin in southeastern Australia, which investigated the impact of weirs on downstream fish movement. Downstream fish movement was monitored at Kennedy's Weir (an overshot, 2 m high weir) on the Broken Creek and Torrumbarry Weir (an undershot, 6.5 m high weir) on the Murray River. A trap used to sample Kennedy's Weir indicated that fish travelled downstream over this weir without sustaining injury or death. A follow-up study, whereby fish were captured below the two respective weirs and translocated upstream where they were radio tagged and released, indicated that while a few fish travelled downstream past the weirs on their return movements back to their home range areas, most were reluctant to do so. This study demonstrates that low-level weirs may inhibit downstream fish movement, and enhancement of downstream fish passage for potamodromous fish species warrants further investigation.     

白马雪山自然保护区北部曲宗贡金妞河流域植被类型调查研究

白马雪山自然保护区北部曲宗贡金妞河流域是保护区海拔最高的区域,拥有丰富多彩的植被类型,孕育和保存着多种珍稀药材、高山花卉等,同时也是特有动植物的极限生境拥有地,是白马雪山保护区的精华所在和缩影。在2009～1012年的不同时段,对126个样地植被进行调查,将流域的植被分为4个植被型6个植被亚型20个群系29个群落,分析该区域多样性植被类型的存在价值和保护价值。     

Modeling intentions to sanction among anglers in a catch-and-release recreational fishery for golden dorado (Salminus brasiliensis) in Salta,Argentina

Catch-and-release (C&R) angling is a powerful tool for reducing impacts on recreationally targeted fishes. Although C&R can be mandated in fisheries through regulation, voluntary adoption and informal management are often critical due to minimal enforcement opportunities. Anglers themselves may play a role in increasing C&R adoption through interpersonal sanctioning (i.e., self-policing). To date, little research has examined factors that predict the willingness of anglers to sanction others’ behavior. We present results from surveys (n = 49) with anglers in Argentina to explore their motivations to sanction other anglers within their stakeholder community. Anglers with the strongest intentions to sanction were younger and more open to adopting best practices, identified fishing as important to their lifestyle, and expressed high environmental concern relative to other anglers. Our findings highlight the role that recreational anglers can play in promoting best practices via interpersonal sanctioning and identify barriers that inhibit this type of action.     

猪带绦虫实验动物模型的建立

为建立猪带绦虫实验动物模型,本实验通过口服激活、未激活囊尾蚴和尾静脉注射激活的囊尾蚴感染昆明小鼠、BALB/c小鼠、SD大鼠、豚鼠、金黄地鼠、沙鼠,对各种鼠体内的绦虫的感染、生长发育及寄生部位等生物学特性进行研究.在感染45 d的金黄地鼠体内检出可见虫体,检出的虫体多数吸附在小肠.本实验建立了猪带绦虫的实验动物模型,使得解决猪带绦虫实验材料的来源问题成为可能,也为猪带绦虫的深入研究奠定了基础.     

Setting New Immunobiological Parameters in the Hamster Model of Visceral Leishmaniasis for <Emphasis Type="Italic">In Vivo</Emphasis> Testing of Antileishmanial Compounds

To establish suitable immunobiological parameters for in vivo testing of new antileishmanial compounds in the golden hamster model of visceral leishmaniasis, two groups of 8 animals were infected each with 10⁵ or 10⁷ stationary promastigotes by the intracardiac route and the clinical and immunoparasitological features were monitored up to day 155 after infection. All animals became infected at both doses, although significant differences were observed between parasite burdens in liver and spleen. The mean number of parasites in animals infected with 10⁷ promastigotes increased by 9.5 times in liver and by 43.1 times in spleen compared with those infected with 10⁵ promastigotes. In animals given the higher dose, the outcome of the disease occurred between days 75 and 90 after infection, whereas no signs of disease were apparent in those given the lower infecting dose. Positive antibody (IgG) responses were detected earlier (week 5–7 after infection) in animals infected with the higher dose than in those infected with the lower dose (week 8–10 after infection), but these responses did not correlate with individual parasitological loads in liver and spleen. An inverse correlation was observed between infecting doses and in vitro spleen lymphocyte proliferation against mitogens (ConA). The proportion of CD4⁺ and CD19⁺ spleen cell increased in animals given the higher infection, whereas it decreased in those given the lower infection compared to naive controls.     

金黄地鼠超数排卵模型的建立

为探讨金黄地鼠超数排卵效果的影响因素,采用孕马血清促性腺激素(PMSG)和人绒毛膜促性腺激素(HCG)对成年雌性金黄地鼠进行超数排卵研究。结果表明,采用40 IU PMSG+40 IU HCG剂量组合的超排效果优于30 IU PMSG+30 IU HCG剂量和20 IU PMSG+20 IU HCG组合;90日龄~150日龄的90 g~150 g的金黄地鼠超数排卵效果最好;人绒毛膜促性腺激素注射后20 h是超排鼠处死取卵的最佳时间,获卵最多。     

基于果实品质主成分分析的‘黄金百香果’栽培架式评价

通过比较在双层架、A形架、篱壁架、棚架、V形架、Y形架和T形架等栽培模式下‘黄金百香果’的果实品质,探究不同栽培架式对‘黄金百香果’果实品质的影响,为筛选适宜‘黄金百香果’的栽培架式提供理论依据。结果表明:‘黄金百香果’在7种栽培架式间的部分果实外观指标(单果重、纵横径、果形指数、可食率、果皮厚度、L值、a值、b值)和部分内在品质指标(可溶性糖含量、可滴定酸含量、维生素C含量、可溶性固形物含量、糖酸比和固酸比)呈显著差异;相关性分析结果表明,7种栽培架式间的‘黄金百香果’的L值与a值、糖酸比与固酸比呈极显著正相关;主成分分析结果表明,篱壁架、A形架、棚架种植下的‘黄金百香果’果实品质综合表现优于Y形架、V形架、双层架和T形架,其中篱壁架种植的果实综合表现最佳。     

金鲳鱼肉和罗非鱼皮明胶改善罗非鱼碎肉鱼糜品质

为了改善罗非鱼碎肉鱼糜制品的品质,研究添加金鲳鱼肉和罗非鱼皮明胶对罗非鱼碎肉鱼糜制品品质的影响。将少量金鲳鱼肉与罗非鱼碎肉混合,制作成鱼糜(金鲳鱼肉质量分别占复合鱼糜总质量的0%、5%、10%、15%、20%),研究鱼糜制品品质的变化规律。通过检测样品的质构、凝胶强度、出水率及颜色发现,随着复合鱼糜中金鲳鱼肉含量的上升,复合鱼糜制品的硬度、胶着性、咀嚼性、弹性、内聚性、凝胶强度、白度均呈现上升趋势,但出水率无显著变化。进一步研究,将罗非鱼鱼肉和金鲳鱼鱼肉以一定比例混合,制作成复合鱼糜,然后加入不同量的明胶,研究复合鱼糜制品品质的变化规律发现,将明胶添加到复合鱼糜制品中会使鱼糜制品的硬度、胶着性、咀嚼性、凝胶强度、白度均上升,出水率下降,但鱼糜的弹性、内聚性、破断距离等差异不显著。试验结果表明,金鲳鱼肉和罗非鱼皮明胶可以用于罗非鱼碎肉鱼糜制品品质的改良。研究结果为改善罗非鱼碎肉鱼糜制品的品质提供了参考。     

3种虹鳟养殖群体的遗传结构及遗传多样性分析

从40个随机引物中筛选出20个,采用随机扩增多态DNA(RAPD)技术,对甘肃金鳟、道氏虹鳟和美国金鳟3个群体进行了遗传结构和遗传多样性分析。结果表明,甘肃金鳟、道氏虹鳟、美国金鳟群体多态位点百分比分别为82.79%、73.33%、77.87%;平均等位基因数分别为1.8239、1.7429、1.7887,有效等位基因数分别为1.4823、1.4281、1.4527;基因多样度分别为0.2820、0.2528、0.2675,Shannon遗传多样性指数分别为0.4219、0.3801、0.4022;以上参数表明,3个群体的遗传多样性均处于偏高的水平,且以甘肃金鳟的遗传多样性最为丰富。甘肃金鳟与美国金鳟之间的遗传距离最大,道氏虹鳟与美国金鳟之间的遗传距离最小。遗传分化指数表明,种内群体间的遗传分化程度很低,而群体内个体间的分化程度很高,变异主要来源于群体内个体间。综合分析认为,甘肃金鳟遗传多样性偏高,有进一步选育的遗传潜力;同时,群体内遗传分化程度较大,说明品种的纯度可能较低,经济性状不够稳定,需进一步选育。