形态性状对长鳍吻鮈体质量的影响效果分析

[目的]分析形态性状对长鳍吻鮈体质量的影响效果,为长鳍吻鮈的人工选育工作提供理论指导。[方法]随机选取120尾驯养的野生长鳍吻鮈,分别测量其体质量(Y)、全长(X1)、体长(X2)、体高(X3)、体宽(X4)、头长(X5)、头宽(X6)、头高(X7)、吻长(X8)、叉长( X9)、眼径( X10)、眼间距( X11)、尾柄长( X12)、尾柄高( X13)、尾鳍长( X14)、眼后头长( X15)共16个性状指标。采用相关分析、通径分析、复相关分析和多元回归分析方法,分别计算了长鳍吻鮈形态性状对体质量的相关系数、通径系数、复相关系数和决定系数,对各形态性状对体质量的影响大小进行剖分,确定了影响长鳍吻鮈体质量的主要外部形态性状。[结果]各形态性状与体质量的相关性均达到极显著水平(P<0.01),但仅全长、头长、头高、眼径、眼后头长对体质量的通径系数达到显著水平(P<0.05),且复相关系数为0.976,是影响体质量的主要性状,其中全长对体质量的直接作用最大(0.663)；决定系数分析结果与通径分析结果的变化趋势一致,即全长、头长、头高、眼径、眼后头长的决定系数较大,其中全长对体质量的决定系数(0.440)最大,其他4个性状主要通过全长影响体质量；应用逐步多元回归分析,经过偏回归系数的显著性检验,建立以体质量的因变量(Y),以全长(X1)、头长(X5)、头高(X7)、眼径(X10)和眼后头长( X15)为自变量的多元回归方程：Y=-30.650+2.534 X1+2.012 X5+2.019 X7+8.716 X10+4.120 X15,经回归预测结果显示估计值与实际值间的差异不显著(P>0.05)。[结论]该方程可用于长鳍吻鮈实际生产中,为长鳍吻鮈选中提供理论依据和测量指标。     

长鳍吻鮈性腺发育的初步观察

采用常规石蜡切片技术对野生长鳍吻鮈(Rhinogobio ventralis(Sauvage et Dabry))性腺进行了组织学观察,描述了其各类型生殖细胞形态及卵巢、精巢的分期特征。结果显示:长鳍吻鮈卵巢为细线状或扁条状,精巢为细线状或直棍状;卵细胞发生经历了卵原细胞、初级卵母细胞和次级卵母细胞3个阶段,精细胞发生经历了精原细胞、初级精母细胞、次级精母细胞、精子细胞及精子5个阶段;性腺发育分为6个时期,卵巢中第Ⅱ时相晚期至Ⅲ时相早期的初级卵母细胞中出现核仁外排现象;同一时期卵巢中存在多种时相的卵母细胞,故推测其卵巢发育类型为部分同步型,精巢为小叶型结构。     

STATIC AND DYNAMIC 18FDG‐PET IN NORMAL HISPANIOLAN AMAZON PARROTS (AMAZONA VENTRALIS)

Positron emission tomography (PET) is often used to stage and monitor human cancer and has recently been used in a similar fashion in veterinary medicine. The most commonly used radiopharmaceutical is 2‐Deoxy‐2‐[¹⁸F]‐Fluoro‐d ‐glucose (¹⁸F‐FDG), which is concentrated and trapped within cells that use glucose as their energy substrate. We characterized the normal distribution of ¹⁸F‐FDG in 10 healthy Hispaniolan Amazon parrots (Amazona ventralis) by performing whole body PET scans at steady state, 60 min after injection. Significant variability was found in the intestinal activity. Avian species are known to reflux fluid and electrolytes from their cloaca into their colon. To evaluate reflux as the cause of variability in intestinal distribution of ¹⁸F‐FDG, dynamic PET scans were performed on the coelomic cavity of six Hispaniolan Amazon parrots from time 0 to 60 min postinjection of radiotracer. Reflux of radioactive material from the cloaca into the colon occurred in all birds to varying degrees and occurred before 60 min. To evaluate the intestinal tract of clinical avian patients, dynamic scans must be performed starting immediately after injection so that increased radioactivity due to metabolism or hypermetabolic lesions such as cancer can be differentiated from increased radioactivity due to reflux of fluid from the cloaca.     

长江干流长鳍吻鮈(Rhinogobio ventralis)繁殖生物学

2012年3月-2014年12月对长江上游宜宾江段采集的521尾野生长鳍吻(鱼句)进行了繁殖生物学研究.结果显示,长鳍吻(鱼句)种群雌雄比为1.41∶1,繁殖期为3-5月,盛期为4月上旬至5月上旬.繁殖季节可通过吻端细小“珠星”鉴别雌雄,雄鱼最小性成熟年龄为2+龄,最小成熟体长为173 mm,体重为90.4 g,成熟系数为0.36％;雌鱼最小性成熟年龄为3+龄,最小成熟体长为185 mm,体重为119.6 g,成熟系数为11.30％.繁殖群体中,雌性优势龄组为3+龄,雄性优势龄组为2+龄和3+龄.统计结果显示,长鳍吻(鱼句)绝对繁殖力(F)为16399-39835(26816±7875)粒/尾,体重相对繁殖力(FW)为162-234(189±23)粒/g,体长相对繁殖力(FL)为877-1659(1231±246)粒/cm.通过对性腺成熟系数、卵径分布频率以及性腺组织切片结果的综合分析认为,长鳍吻(鱼句)属于完全同步产卵类型.     

Bark Beetle Demography in a Jeffrey Pine Stand as Influenced by Mechanized Thinning and Prescribed Fire

Forest thinnings implemented with cut-to-length and whole-tree harvesting systems followed by underburning were evaluated for their effects on bark beetle prevalence in pure, uneven-aged Jeffrey pine (Pinus jeffreyi Grev. & Balf.) interspersed with isolated California white fir (Abies concolor var. lowiana [Gord.] Lemm.). Based on pitch tube counts in a stand with a moderate bark beetle population in its pine component, the Jeffrey pine beetle (Dendroctonus jeffreyi Hopkins) generally preferred larger trees before treatment implementation, but after exhibiting mixed pretreatment tendencies concerning stand density demonstrated a posttreatment proclivity toward higher density. Cut-to-length thinning followed by underburning increased the pine beetle population while whole-tree thinning unaccompanied by burning reduced it. Tree mortality was induced by the bark beetle infestation but was not its sole cause. Pitch tube abundance on white fir far exceeded that on Jeffrey pine, and the greatest influence on the fir engraver (Scolytus ventralis LeConte) population was the prevalence of its host tree. The responses presented herein to these thinning and burning practices, which are being increasingly utilized in forest restoration efforts in the western USA, provide natural resource managers insight into potential forest health outcomes when implemented in Jeffrey pine and similar dry site forest types.     

金沙江长鳍吻鮈的含肉率及其营养成分分析

试验测定了长鳍吻鮈(Rhinogobio ventralis)含肉率及其肌肉常规营养成分(蛋白质、脂肪、灰分、水分)、矿物元素(钙、磷、钠、镁、铜、锌、铁、锰、铬、硒)和氨基酸组成,并对其营养价值作了综合评定。结果表明,长鳍吻鮈含肉率为(69.51±4.91)%;肌肉(鲜样)中水分、粗蛋白、粗脂肪和灰分的含量分别为(70.14±0.72)%、(17.26±0.47)%、(11.28±0.64)%、(0.87±0.03)%;肌肉中17种常见氨基酸(除色氨酸外)总含量为(16.15±0.26)%;其中,必需氨基酸含量为(6.31±0.11)%,占氨基酸总含量的39.10%。必需氨基酸与非必需氨基酸含量的比值为64.20%。鲜味氨基酸含量为(6.27±0.11)%,占氨基酸总含量的38.83%。必需氨基酸指数为82.17。长鳍吻鮈的限制性氨基酸主要是异亮氨酸、蛋氨酸+胱氨酸、缬氨酸。10种矿物元素中,钙、磷、钠、镁4种常量元素的平均含量在296.32～3278.14μg/g,而铜、锌、铁、锰、铬、硒6种微量元素含量的平均值则在0.06～112.5μg/g;平均钙磷比为1∶2.1。     

金沙江长鳍吻鮈年龄与生长的研究

[目的]研究金沙江长鳍吻鮈年龄与生长，为其资源的有效保护和合理利用积累基础生物学资料。[方法]从金沙江丽江市永胜县片角乡江段收集161尾长鳍吻鮈作为样本，用鳞片鉴定年龄并退算鱼的体长，通过相关分析，拟合出长鳍吻鮈体长与鳞长、体长与体重的回归方程，求出其体长和体重的生长方程及生长速度和生长加速度方程。[结果]长鳍吻鮈渔获物由5个年龄组组成，以1-3龄为主；体长（L）与鳞径（R）呈线性关系：L=25．373＋56．331R；体长（L）与体重（形）的关系式为形=1．7×10^-5L^3.0073；其生长规律用von Bertalanffy方程表示为Lt=278．6966（1-e^-0.32962（t＋0.25886）），Wt=383．4364（1-e^-0.32962（t＋0.25886））^3.0073；生长拐点年龄为3．08龄，此时的体长和体重分别为186．02mm和113．69g。[结论]严格限制捕捞3龄以下约200mm长的个体，有利于该鱼资源科学保护与增值。     

北京鸭的胰腺分叶及其排泄管道

本实验共用北京鸭30只,颈动脉放血,福尔马林固定。在对胰腺的解剖观察中,发现一条前人未曾报道过的第一胰管。观察结果如下:北京鸭的胰腺,位于十二指肠升袢和降袢之间,分为背侧胰叶、腹侧胰叶和脾胰叶。背侧胰叶和腹侧胰叶在多数个体彼此分离,少数个体两叶间有腺组织相连。脾胰叶仅和背侧胰叶相连。自背侧胰叶尾端发出第一胰管,在十二指肠升、降袢转折处附近通入十二指肠升袢肠壁,该胰管前人未报道过。自背侧胰叶和腹侧胰叶的头端,分别发出背侧胰管和腹侧胰管,在十二指肠末端,肝小肠管和胆囊小肠管入肠处的前方入肠。     

雏鸡投射向外侧膝状体腹侧核的视顶盖细胞形态研究

鸟类的一些视觉信息经由视顶盖Ⅰ层细胞（Ⅰ细胞）传递到外侧膝状体腹侧核（nucleus geniculatus lateralis ventralis,GLv）,用于色觉、瞳孔反射和视觉运动.使用羰花青荧光染料DiI逆向神经标记技术研究了这些投射向GLv核的视顶盖Ⅰ细胞的形态特征.根据标记细胞的胞体和树突野大小及树突分枝特点,雏鸡投射到GLv核的视顶盖Ⅰ细胞可分为“矛状树突Ⅰ细胞”和“叉状树突Ⅰ细胞”,前者具有小型纺锤状的细胞体和垂直伸延的1支尖端树突,后者具有较大三角形或多角形的细胞体和多支上行性树突.多数标记树突的末端部水平分布于视顶盖F层,和终止于此层的视神经终末部的形态相一致.     

长江干流长鳍吻鮈的生物学研究

长江干流重庆木洞江段长鳍吻鮈渔获物中1～3龄个体占绝大多数。新年轮形成时间在3-6月。体长与鳞径成直线相关,体长与体重成指数相关,体长生长速度随年龄增加而逐渐减慢;体重生长拐点年龄为3．29,拐点年龄前体重随年龄增加而增速增长,拐点年龄后则减速增长;1～4龄为长鳍吻鮈快速生长期。秋季丰满度和脂肪系数均高于冬季。繁殖群体主要为1～4龄,绝对繁殖力随体长和体重的增加而增加,相对繁殖力随体长、体重的增加而减少。生态策略趋向于r-选择,长江干流的长鳍吻鮈处于过度捕捞状态。