Effects of prebiotic mannan oligosaccharide on the growth,survival, and anxiety-like behaviors of zebrafish (Danio rerio)

A study was designed to investigate the possible positive prebiotic effects of mannan oligosaccharides (MOS) on growth and reduction of anxiety behaviors in zebrafish (Danio rerio). The experimental diets were supplemented with 0, 2, 4, 6, or 8 g MOS kg^?1 and were fed to juvenile fish (0.47 ± 0.017 g) in triplicates for six weeks. Significant differences were found in the final body weight, body weight intake, percent body weight intake, and specific growth rate among treatments. The regression analyses showed that the optimum MOS level was 4–4.1 g MOS kg^?1 diet. Fish fed 4 g MOS kg^?1 feed showed higher survival than the other treatments. Also, using the novel tank test, fish fed with 4 g MOS kg^?1 diet showed lower anxiety by swimming in the upper portion of the tank. The other behavior parameters remained unaffected by the prebiotic. The results indicated the beneficial effect of the prebiotic MOS on growth and partly on welfare of zebrafish juveniles.     

Stress exposure during the preimplantation period affects blastocyst lineages and offspring development

We found retardation of preimplantation embryo growth after exposure to maternal restraint stress during the preimplantation period in our previous study. In the present study, we evaluated the impact of preimplantation maternal restraint stress on the distribution of inner cell mass (ICM) and trophectoderm (TE) cells in mouse blastocysts, and its possible effect on physiological development of offspring. We exposed spontaneously ovulating female mice to restraint stress for 30 min three times a day during the preimplantation period, and this treatment caused a significant increase in blood serum corticosterone concentration. Microscopic evaluation of embryos showed that restraint stress significantly decreased cell counts per blastocyst. Comparing the effect of restraint stress on the two blastocyst cell lineages, we found that the reduction in TE cells was more substantial than the reduction in ICM cells, which resulted in an increased ICM/TE ratio in blastocysts isolated from stressed dams compared with controls. Restraint stress reduced the number of implantation sites in uteri, significantly delayed eye opening in delivered mice, and altered their behavior in terms of two parameters (scratching on the base of an open field test apparatus, time spent in central zone) as well. Moreover, prenatally stressed offspring had significantly lower body weights and in 5-week old females delivered from stressed dams, fat deposits were significantly lower. Our results indicate that exposure to stress during very early pregnancy can have a negative impact on embryonic development with consequences reaching into postnatal life.     

笼养东北虎(Panthera tigiris altacia)的行为观察(英文)

从1998年3月至2001年3月,采用全事件取样法和焦点动物取样法对哈尔滨动物园的4只笼养东北虎(1雄3雌)进行了系统的行为观察。笼养东北虎的行为可以分成5种主要的方式:运动、卧息、睡眠、取食和其他行为(饮水、排尿、修饰、嬉戏和站立)。在所有的行为类型中,睡眠和运动所占的比值很高(占整个时间分配的75.18%);而卧息、取食和其他行为仅占24.82%。除了取食,一只雄性和其中两种雌性东北虎的其他4种主要行为具有相似的活动规律,在白昼和夜晚各有一个活动高峰;而另外一只雌性东北虎在夜晚则具有两个活动高峰期。表2参16。     

猪舍场景下的生猪目标跟踪和行为检测方法研究

针对猪舍内光照情况复杂、目标与背景颜色较为接近、相机视角与参数不佳等环境与硬件条件的不足,导致生猪跟踪过程中精度低、稳定性差的问题,充分结合实际场景,提出了一种优化特征提取的压缩感知跟踪算法。优化跟踪窗口为椭圆形,以接近生猪体态;并结合灰度和纹理特征,优化传统压缩感知算法特征提取过程;划分猪舍区域,依据生猪所处位置来判断其当前行为。随机选取猪舍内不同场景、不同光照强度、不同生猪品种的多段视频进行实验,实验结果表明：中心点均方根误差均值为25.44,分别是传统压缩感知算法、模板更新跟踪算法和Camshift跟踪算法的60.32%、33.33%、32.57%;中心点均方根误差方差为70.26,分别是传统压缩感知算法、模板更新跟踪算法和Camshift跟踪算法的7.13%、47.62%、17.16%;跟踪速度达到19.3帧/s。     

青岛老城区里院街区空间解析——基于城市设计基础理论的分析

“里院”是青岛老城一种特有的居住形式,文章运用图底理论,行为场所理论这些当代城市设计的基础理论,对里院街区空间和里院街区开敞空间进行了分析。保护里院街区空间也不应仅仅停留在物质形态,重点也是要考虑居民的需求,以尊重他们的行为方式作为前提,在此基础上提高他们的生活品质。     

Behavior and mortality of caught-and-released bonefish (Albula spp.) in Bahamian waters with implications for a sustainable recreational fishery

Bonefish (Albula spp.) are a widely distributed group of morphologically indistinguishable marine fish species, that provide a recreational sport fishery, that is important for many local economies. Although the majority of angled bonefish are released following capture, little is known about their behavior or post-release survival. Using ultrasonic transmitters and small visual floats, we assessed behavior and mortality of bonefish following catch-and-release angling at spring water temperatures (25.5-27.3 °C) in two regions of the Bahamas with differing shark abundances. All observed mortality occurred within 30 min of release and was a direct result of predation by sharks. In the low shark abundance areas, all released bonefish survived, whereas in the high shark abundance areas, some mortality (39%) was observed. Exhaustively angled fish exposed to air had problems maintaining equilibrium following release. These fish typically spent substantial periods of the first 30 min post-release remaining stationary, then moved in rapid bursts. The results of this study, highlight the benefits of angling and releasing bonefish quickly, minimizing handling and particularly air exposure. Furthermore, when shark predation threat is high, anglers should avoid releasing bonefish in the immediate area. The conservation of exploited recreational bonefish fisheries will depend upon the development and dissemination of science-based catch-and-release strategies.     

Florida manatees, Trichechus manatus latirostris, respond to approaching vessels

Florida manatees inhabit shallow coastal and estuarine waters of the southeast US, a range that brings them into frequent contact with vessels. More than 30% of documented annual mortalities are attributed to vessel collisions, and most living animals bear the scars of multiple, non-lethal encounters. To document the behavior of manatees in the presence of vessels, we recorded their movements with an overhead video system. We scored six aspects of behavior during 170 vessel approaches, and compared their behavior with 187 control segments when no boats were present. Manatees in shallow waters and at the edge of the channel responded to approaches by orienting towards the nearest deep water, a boat channel, and increasing their swimming speed. Close boat approaches and shallow water depths exacerbated these responses. Our results indicate that manatees detect and respond to approaching vessels with an apparent flight response, a response which includes movement towards deeper water. If given sufficient time, i.e., approached or passed slowly, the manatees may then be able to reach deeper water and safe depths.     

Acoustic stimulation as a tool in African wild dog conservation

A 9-year study of the African wild dog, Lycaon pictus, was conducted in Hwange National Park, Zimbabwe, primarily in Colophospermum mopane woodland and Combretum thicket. A protocol using both playbacks and human simulations of long distance calls was developed to facilitate radio-collaring operations and data collection. Wild dogs were known to be in the area prior to each trial (n=32). Dogs approached calling stations in 84% of trials from distances up to 2-km. When dogs hooed (n=18; eight packs and one group), they approached the stimulus in all but one trial. Mean time to approach was ca. 13.9±2.6 min. (n =11 trials, range 1-56 min). Findings demonstrate that playbacks are an effective conservation tool particularly where road networks are limited and/or thick habitat restrict off-road driving. Potential application lies in park boundary areas where snaring occurs and in translocations from areas of high wild dog/human conflict to refuges. In dense habitat or less traveled areas, this technique, in conjunction with other methods, may prove useful in population surveys.