Effects of natural barriers on the spillover of a marine mollusc: implications for fisheries reserves

• 1. The movement of organisms and dispersal of propagules is fundamental to the maintenance of populations over time. However, the existence of barriers, created through the spatial configuration of habitats, may significantly affect dispersal patterns and thus influence community dynamics and resource sustainability.
• 2. Within marine environments unstructured or open habitats may form partial or complete ecological barriers due to elevated risk of predation or physical stresses associated with them. The existence and effects of such barriers may be of particular importance when considering the establishment of marine protected areas with a fisheries enhancement focus.
• 3. In this paper, the spillover of post‐settlement queen conch (Strombus gigas) from a protected area in the Turks and Caicos Islands is investigated. It is hypothesized that the reserve boundaries overlap with a series of shallow, sand habitats that effectively enclose the protected population, reducing the spillover of conch into the adjacent fished areas.
• 4. To test this, density gradient maps for juvenile and adult conch populations were constructed using underwater visual survey data at 68 sites within and surrounding the protected area. These maps illustrate very low densities coinciding with poor, shallow sand habitats along the two marine boundaries of the reserve where spillover is expected to take place.
• 5. These sand habitats are thought to create ecological barriers to a slow, sedentary gastropod largely due to their shallowness (physical stresses of solar exposure or anoxia) and lack of food reducing the tendency of individuals to move across these areas, despite the 10‐times higher density of adult queen conch observed in the protected area compared with outside.

Copyright © 2003 John Wiley & Sons, Ltd.     

萧山浆蜂与本地意蜂产浆性能的对比研究

对萧山浆蜂和本地意蜂产浆的王台接受后，台平均产浆量和批次平均产浆量等主要产浆性能进行了对比试验。试验结果显示：（1）萧山浆蜂的产浆王台接受率，台平均产浆量和批次平均产浆量均显高于本地意蜂；（2）采用萧山浆蜂其总产浆量可比采用本地意蜂的增加190％。通过试验认为，萧山浆蜂的产浆性能大大优于本地意蜂。     

保幼激素类似物ZR_（512）对蜜蜂蜂王胚后发育的调控作用

在蜜蜂人工育王过程中，用保幼激素类似物ＺＲ５１２滴注于王台内蜂王浆中的方法，研究ＺＲ５１２对蜂王发育的调控作用．每只蜂王幼虫ＺＲ５１２的滴注量分别为０．０１、０．１０、１．００μｇ．三种处理蜂王的未封盖幼虫期，中华蜜蜂分别为１２３．３、１２６．７、１２３．５ｈ，分别比对照组（１１４．４ｈ）延长９．０、１２．３、９．１ｈ，差异显著或极显著（Ｐ＜０．０５或Ｐ＜０．０１）；意大利蜜蜂分别为１１６．０、１１５．０、１１５．０ｈ，分别比对照组（１１１．３ｈ）延长４．７、３．７、３．７ｈ，差异极显著（Ｐ＜０．０１）．蜂王幼虫封盖后的发育期，中华蜜蜂和意大利蜜蜂分别为１６２．６—１６４．９ｈ和１７７．２—１８０．４ｈ，各处理组与对照组的差异均不显著（Ｐ＞０．０５）．由此可见，ＺＲ５１２能够显著延长蜜蜂蜂王的幼虫取食期，促使蜂王在胚后发育阶段的超常发育．这是ＺＲ５１２促进蜂王初生重增加的主要原因．在幼虫期施加保幼激素类似物ＺＲ５１２，对蜂王封盖期的发育无影响．     

保幼激素类似物ZR_（512）对蜜蜂蜂王初生重的影响

在蜜蜂人工育王过程中，用保幼激素类似物ＺＲ５１２滴注于王台内的蜂王浆中，每只蜂王幼虫ＺＲ５１２的滴注量分别为０．０１、０．１０、１．００μｇ．处理组中华蜜蜂蜂王平均初生重分别为１９１．３、１９３．２．１９７．７ｍｇ，分别比对照组蜂王初生重（１７９．９ｍｇ）提高１１．４、１３．３、１１．８ｍｇ．差异极显著（Ｐ＜０．０１）；意大利蜜蜂蜂王初生重分别为２４７．８、２４０．１、２３６．７ｍｇ，比对照组蜂王初生重（２０９．１ｍｇ）分别提高３８．７、３１．０、２７．６ｍｇ，差异均极显著（Ｐ＜０．０１）．ＺＲ５１２处理后，中华蜜蜂王初生重最高可达２１０ｍｇ，意大利蜜蜂蜂王初生重最高可达２７４ｍｇ．ＺＲ５１２处理蜂王幼虫，对蜜蜂蜂王初生重具有显著的调控作用．为在养蜂生产上培育优质蜂王提出了新的途径．     

单、复式移虫育王对王台接受率和蜂王初生重的影响

对单、复２种不同形式移虫育王的王台接受率和蜂王初生重进行了对比试验．试验结果显示：（１）单式移虫的王台接受率（５８．１１％）与复式移虫的王台接受率（６２．６７％）差异不显著（Ｐ＞０．０５）；（２）单式移虫育出的蜂王初生重（Ｘ＝２３５．９６ｍｇ）与复式移虫育出的蜂王初生重（Ｘ＝２４１．５７ｍｇ）差异不显著（Ｐ＞０．０５）．据此，我们认为培育蜂王应采用单式移虫以省工省时．     

南宁市双色中华蜜蜂探析

近几年来,南宁的许多中华蜜蜂(以下简称中蜂)养殖场经常出现麻色蜜蜂和黄色蜜蜂混同一起的种群(简称双色群),引起中蜂养殖者的高度关注。笔者在南宁市吴圩镇(广西国有七坡林场)定地养殖中蜂十余年,每年都有少量双色蜂种群出现,为此对双色中华蜜蜂进行了详细观察、记录、验证,认为双色蜂不是一个独立品种,是外来黄色蜂种与本地麻色蜂种杂交的结果。     

鸡球虫病体液免疫研究进展

鸡球虫病的免疫对鸡的养殖业具有重要的意义。一直以来都以药物防治为主,由于耐药虫株的产生和药物残留对人体造成的不良影响,免疫防治受到人们的普遍关注。了解免疫机制是提高免疫防治的有效方式。鸡球虫免疫机制主要包括细胞免疫,体液免疫。体液免疫通过循环抗体,粘膜抗体,母源抗体对鸡体产生保护作用。     

Reproductive and Morphological Quality of Commercial Honey Bee (Hymenoptera: Apidae) Drones in the United States

Exploration into reproductive quality in honey bees (Apis mellifera Linneaus (Hymenoptera: Apidae) largely focuses on factors that affect queens, with drones primarily being considered insofar as they pass on effects of environmental stressors to the queen and subsequent offspring. In those studies that consider drone quality explicitly, a primary focus has been on the dimorphic nature of drones laid in worker cells (either through rare queen error or worker reproduction) as compared to drones laid by the queen in the slightly larger drone cells. The implication from these studies is that that there exists a bimodality of drone morphological quality that is related to reproductive quality and competitive ability during mating. Our study quantifies the presence of such small drones in commercial populations, finding that rates of ‘low-quality’ drones are far higher than theoretically predicted under optimum conditions. Observations from commercial colonies also show significant inter-colony variation among the size and fecundity of drones produced, prompting speculation as to the mechanisms inducing such variation and the potential use of drone-quality variation for the colony- or apiary-level exposure to nutrition, agrichemical, or parasitic stressors.     

蜜蜂性比的分子调控机制研究

蜜蜂性比是指蜂群中雌性蜜蜂与雄性蜜蜂的比例。按亲属选择理论和性比原理预测 ,工蜂则可能对雌性性别更多地投资 ,这样蜂王和工蜂在决定性比问题上存在矛盾。本试验通过RAPD技术测定蜂王交配次数 ,并利用亲属选择和性比理论 ,研究了蜂群中的性比冲突问题。研究结果支持了工蜂调控蜜蜂性比的观点。     

蜜蜂高产蜂胶蜂种选育研究

蜂胶的开发利用使得蜂胶生产远不能满足市场需求.通过引入高加索系列品种、本意、喀尔巴阡以及东北黑蜂,采用蜂王人工授精技术加以组配,进行筛选.培育出高产蜂胶的优良杂交组合,借以提高蜂胶产量,满足蜂胶市场需求,使蜂农增收,提升人们的健康水平.