尖吻蝮幼蛇各生长阶段饲养技术研究

2015年9月—2016年11月,随机挑选自主孵化的尖吻蝮幼蛇60条在人工环境下进行饲养,研究了尖吻蝮幼蛇各个阶段适宜食物、适宜养殖方式和日常管理程序,并提出规模化养殖尖吻蝮幼蛇的适宜模式.结果表明:尖吻蝮幼蛇以箱式或笼式养殖为佳.初生尖吻蝮幼蛇的饲养以蛙类幼体和多疣壁虎作为开口食物效果较好,开口率达到98.33%;2月龄以上幼蛇进食壁虎、小白鼠能力显著增加,第一个冬眠期后幼蛇以多疣壁虎成功开食,10月龄尖吻蝮已经能稳定的捕食小白鼠.日常管理建议周期化管理,从进食开始到下次进食之间为一个周期,周期内每日1检,及时清理死食和粪便,喂食定期同步进行,一个周期内蛇舍消毒一次.     

蛇病防治

1霉斑病 由霉菌引起,主要由于蛇窝内过于潮湿或不卫生引起.在梅雨季节,人工饲养的蛇,特别是蝮蛇、尖吻蝮此病尤为多见.     

原尾蜥虎的繁殖生态学研究

为研究原尾蜥虎(Hemidactylus bowringii,Gray)的繁殖生态学,于2005和2006年4月～8月在肇庆市郊捕获761条不同大小的个体.繁殖雌体的最小SVL为45.68 mm,大于此大小的个体被判定为性成熟.幼体组个体大小及头部大小两性间无差异,而成年原尾蜥虎具有两性异形,雄性大于雌性且具有较大的头部,因此原尾蜥虎个体大小的两性异形是性成熟以后发生的.饲养于实验室的母体于5月下旬至8月中旬产卵,繁殖雌体具有年产多窝卵的潜力.卵重变异系数为0.12.多数母体单次产2枚卵,少数产1枚,窝卵重和卵重均与母体体长无关.相对窝卵重与母体体长呈显著的负相关,表明较小的母体具有相对较大的繁殖输出.因雌体繁殖会滞缓其生长,小母体具有相对较大的繁殖输出至少部分地解释了成年原尾蜥虎雌性小于雄性.     

人工巢箱条件下大山雀的窝卵数与繁殖成功的关系

2004—2006年,利用人工巢箱在吉林省左家自然保护区次生林中对大山雀（Parus major）的窝卵数与繁殖成功的关系开展了研究。研究表明：大山雀对人工巢箱的利用率逐年减少,年份间差异显著（P〈0．05）。营巢成功率为74．3％,营巢失败的主要原因是人为破坏和天敌占用。大山雀的窝卵数为6—14枚,平均10．2枚,常见窝卵数为10—12枚,卵质量平均为（1．47±0．12）g,卵大小平均为16．5min×12．9min。孵化期平均为（13．8±1．4）d,平均出雏率为（88．4±1．3）％,育雏期平均为（17．3±0．9）d,平均出飞率为（78．1±2．0）％。大山雀窝卵数与孵化期、出雏率、育雏期和出飞率显著正相关.大山雀繁殖成功率逐年增加,不同年份间繁殖成功率差异极显著（P〈0．01）,窝卵数与繁殖成功率无明显相关性。     

黄喉拟水龟母体大小对繁殖性能的影响

对黄喉拟水龟Mauremys mutica同一种群中3种规格（小型个体783.0 g±55.2 g、中型个体991.3 g±62.3 g和大型个体1248.5 g±122.9 g）母体的繁殖性能进行了研究。结果表明：在繁殖季节,不同规格母体的月产卵量差异较明显,其中小型母体在产卵期首月和末月产卵量所占比例相对较高;3种规格母体的平均产卵量、受精率和孵化率与母体的大小呈正相关,平均窝数与母体大小则呈负相关;窝卵数、卵重、卵宽也与母体规格呈正相关,其中窝卵数的差异极显著（P〈0.001）。在代表卵形状的卵长径与短径比值中,小规格母体产的卵略长,但差异不显著;大规格母体产的稚龟则显著大于小规格母体产的稚龟（P〈0.05）。本研究结果表明,以大规格母体作为繁殖亲本,可以获得更多的后代。     

大鸨窝卵数及营巢成功率

2000年和2001年的4—7月,在内蒙古扎赉特旗草原,采用野外直接观测法对野生大鸨的窝卵数、营巢成功率进行了研究,结果表明:大鸨种群的平均窝卵数为(2.52 0.98)枚/巢(n=53);窝卵数与产卵期值、出巢数与产卵期值、窝卵数与卵大小之间呈负相关;产卵期值与孵化率之间存在极显著的负相关关系,巢径与窝卵数之间存在显著的正相关关系,巢的其余指标均与窝卵数呈正相关;大鸨的孵化率24.53%,营巢成功率为38.10%,雏鸟存活率为38.46%。     

蛇的四季管理

春季 惊蛰过后,蛇纷纷出洞活动,如眼镜蛇、尖吻蝮、蝮蛇.有的稍晚些,如烙铁头、竹叶青在清明前后,银环蛇则晚至立夏,活动最适温度20～30℃.眼镜蛇、银环蛇在26～30℃.清明前后气候时暖时寒,蛇爬出洞外晒太阳取暖,这时蛇的活动能力较差,是捕捉和运输的好时机,并且不久即可产卵繁殖.刚出蛰的蛇在2～3周内进食量极少,也少活动,要注意保暖.不宜清扫场内卫生,也不宜采毒.     

三疣梭子蟹形态指标、体重与抱卵量的关系

为促进三疣梭子蟹育苗技术发展,测定亲蟹的全甲宽、甲宽、甲长、体高等16项形态指标及抱卵体重和去卵重,分析形态指标、体重与亲蟹抱卵量的关系.结果说明,除内额宽与抱卵量相关性不显著(P>0.05)外,试验所测形态指标问的表型相关都呈极显著水平.然而,形态指标间存在多重共线性关系,主成分分析表明第一主成分所构成的信息量为总信息量的84.379%,反映了绝大多数信息,但通径系数检验不显著,说明仅借助形态指标难以准确估计亲蟹抱卵量.亲蟹的体重与抱卵量间存在极显著正相关(P<0.01),因此可用体重来推算抱卵量.     

莆田黑猪繁殖性状遗传规律的研究

应用HARVEY程序对莆田黑猪繁殖性状的表型参数和遗传参数进行了分析研究，结果表明：平均乳头数13．22个，产仔数10．17头，产活仔数9．61头，初生窝重8．34kg，初生个体重0．82kg，20日龄仔数8．89头，20日龄窝重35．07kg，断奶仔数8．83头，断奶窝重48．06kg，断奶个体重5．38kg。繁殖性状乳头数、产仔数、产活仔数、初生窝重、初生个体重、20日龄窝重、断奶仔数、断奶窝重和断奶个体重的遗传力分别为0．193、0．160、0．186、0．223、0．247、0．046、0．016、0．33l和0．284。繁殖性状间的表型相关介于-0．642～0．808之间，遗传相关和环境相关分别在-0．714～0．982和-0．770～0．880之间。乳头数与产仔数、活产仔数、初生窝重、断奶仔数间的遗传相关为负值，而表型相关和环境相关为正值；断奶窝重与所有繁殖性状间都存在着正的表型相关、遗传相关和环境相关，且窝性状的相关性都较强，窝性状和个体性状(初生个体重、断奶个体重)存在着负的遗传相关。断奶窝重可以作为莆田黑猪繁殖性状的重要选择指标。     

松辽黑猪繁殖性状遗传规律的研究

对松辽黑猪繁殖性状的表型参数和遗传参数进行了分析研究,结果表明:乳头数14.11个,产仔数13.45头,产活仔数12.54头,初生窝重15.79kg,初生个体重1.37kg,断奶仔数10.04头,断奶窝重122.84kg,断奶个体重12.45kg。繁殖性状乳头数、产仔数、产活仔数、初生窝重、初生个体重、断奶仔数、断奶窝重和断奶个体重的遗传力分别为0.528,0.138,0.118,0.427,0.382,0.147,0.243,0.212。繁殖性状间的表型相关介于-0.481～0.901之间,遗传相关在-0.371～0.913之间。断奶窝重与所有繁殖性状间都存在着正的表型相关和遗传相关,因此断奶窝重可以作为松辽黑猪繁殖性状的重要选择指标。     

City size effects, trends, and policies

As cities increase in size, so do wage rates for the same work. There is evidence that the wage differential is persistent and stable over time, which suggests that the differential does not arise from a lack of adjustment that is in process of correction. Indeed, there is an inverse relation between size and growth rate. Large metropolitan areas with high wage rates have been losing population in recent years, which is hardly a sign that their higher wage rates are temporary inducements to workers to move into those cities. It is much more plausible that the differential is a more-orless permanent money payment that compensates urban residents for costs they bear as population size increases. This argument does not deny that there are nonwage benefits as well as costs of city size, that city size effects may vary between individuals and groups, or that there may be scope for improved policy on population distribution. Nonetheless, the benefits of size seem to be outweighed by the costs; all types and groups of people generally can and do move about until alternative locations are less attractive than their current location; and solutions to population distribution problems will often emerge as byproducts to the solutions of more basic problems.     

The size, scale, and shape of cities

Despite a century of effort, our understanding of how cities evolve is still woefully inadequate. Recent research, however, suggests that cities are complex systems that mainly grow from the bottom up, their size and shape following well-defined scaling laws that result from intense competition for space. An integrated theory of how cities evolve, linking urban economics and transportation behavior to developments in network science, allometric growth, and fractal geometry, is being slowly developed. This science provides new insights into the resource limits facing cities in terms of the meaning of density, compactness, and sprawl, and related questions of sustainability. It has the potential to enrich current approaches to city planning and replace traditional top-down strategies with realistic city plans that benefit all city dwellers.     

水库堤坝囟土白蚁蚁后体长与巢积、巢深、群体数量之间相关性研究

囟土白蚁(Odontotermes fontanellus Kemner)是严重危害安徽中小水库堤坝的主要蚁种.为了科学抽样,以幼年和成熟蚁群蚁中蚁后的体长与体积为指标,用DPS软件进行分析.结果表明:(1)蚁后体长与体积之间成指数函数曲线关系,方程为:Y=0.074e0.068 4x(r=0.953 5);(2)蚁后体长与蚁巢体积之间成幂函数曲线关系,方程为:Y=5×10-5X5.521 6(r=0.855 0);(3)蚁后体长与工蚁数、兵蚁数、幼蚁数、整巢蚁数之间数量关系,有4条幂函数曲线,方程分别为:Y=0.001 3X4.812 6(r=0.904 9),Y=3×10-5X4.938 8(r=0.893 5),Y=0.384 4X3.268(r=0.709 0),Y=0.032 2X4.173(r=0.925 9);(4)蚁后体长与蚁巢深度之间的数量关系是一幂函数,其方程为:Y=0.345 3X1.469 4(r=0.653 4).通过以上方程,可估计出该群体大小和蚁巢体积,为堤坝白蚁的防治提供科学依据.     

Nest parasitism, productivity, and clutch size in purple martins

Mean maximum nestling weight of purple martins decreased with increase in brood size from three to five. Martins in the absence of acarine nest parasites produced young heavier than parasitized young of the same brood size; in addition, unparasitized nestlings tended to reach a maximum weight equivalent to that of young in parasitized broods of one less member. Modal brood size for parasitized and unparasitized martins was four, but there was a significant trend toward production of broods of five by mite-free birds, and of broods of three by parasitized parents. This suggests a potentially important role for nest parasitism in the determination of clutch size in martins and other birds.     

Spontaneous tomato fruit size,shape, and weight mutations and traits evolution

The results of study of spontaneous fruit size and shape mutants and inheritance of these traits in tomato are given and genetic processes are explained. It is concluded that the diversity of tomato fruit shape and weight in the collection is due mainly to mutations of genes—diameter of fruit width and diameter of height joined into an ovate cluster.     

Burial rates, growth rates, and size distributions of deep-sea manganese nodules

The size distributions of deep-sea manganese nodules are consistent with a simple model of uniform growth at a few millimeters per million years and with the same probability of burial for all nodules, regardless of size. The model suggests that most nodules spend 1 million years or less on the sea floor.     

Microcephalin, a gene regulating brain size, continues to evolve adaptively in humans

The gene Microcephalin (MCPH1) regulates brain size and has evolved under strong positive selection in the human evolutionary lineage. We show that one genetic variant of Microcephalin in modern humans, which arose approximately 37,000 years ago, increased in frequency too rapidly to be compatible with neutral drift. This indicates that it has spread under strong positive selection, although the exact nature of the selection is unknown. The finding that an important brain gene has continued to evolve adaptively in anatomically modern humans suggests the ongoing evolutionary plasticity of the human brain. It also makes Microcephalin an attractive candidate locus for studying the genetics of human variation in brain-related phenotypes.     

Hair color, molt, and testis size in male, short-tailed weasels treated with melatonin

Melatonin in beeswax was implanted in male weasels (Mustela erminea). Brown weasels and white animals undergoing the spring change to the brown pelage and reproductive activity molted, grew a new white coat, and became reproductively quiescent after treatment. Controls retained or acquired the brown coat and developed or maintained enlarged testes. Treated weasels with pituitary autografts under the kidney capsule grew brown hair after hair growth was initiated by plucking. It is suggested that the pineal gland product, melatonin, initiates changes in the central nervous system and endocrines which result in molting, growth of the white winter pelage, and reproductive quiescence in the weasel.     

Biomass, size, and trophic status of top predators in the Pacific Ocean

Fisheries have removed at least 50 million tons of tuna and other top-level predators from the Pacific Ocean pelagic ecosystem since 1950, leading to concerns about a catastrophic reduction in population biomass and the collapse of oceanic food chains. We analyzed all available data from Pacific tuna fisheries for 1950-2004 to provide comprehensive estimates of fishery impacts on population biomass and size structure. Current biomass ranges among species from 36 to 91% of the biomass predicted in the absence of fishing, a level consistent with or higher than standard fisheries management targets. Fish larger than 175 centimeters fork length have decreased from 5% to approximately 1% of the total population. The trophic level of the catch has decreased slightly, but there is no detectable decrease in the trophic level of the population. These results indicate substantial, though not catastrophic, impacts of fisheries on these top-level predators and minor impacts on the ecosystem in the Pacific Ocean.