Novel microsatellite markers for Atlantic sturgeon (Acipenser oxyrinchus) population delineation and broodstock management

Twenty‐one new disomic, polymorphic microsatellite DNA markers were isolated in Atlantic sturgeon, Acipenser oxyrinchus oxyrinchus. These markers yielded a total of 220 alleles in a survey of 16 fish; two to 21 alleles/locus were observed. Each locus segregated in a Mendelian fashion when tested in a family, and a set of 14 of the loci distinguished between siblings and half‐siblings. Average observed heterozygosity ranged from 18.8 to 100.0%, and no linkage disequilibrium was detected. These loci should detect sufficient genetic diversity to allow kinship analysis for broodstock management, gene marking for stocking assessment and life history studies, and delineation of fine‐scale population structure.     

半散放东北虎行为活动时间的分配

1998年5年－2001年4月在黑龙江东北虎林园,采用焦点动物取样法对10只半散放东北虎（5雌5雄）全年的昼间行为活动时间分配进行了研究。结果表明：（1）半散放东北虎的运动（37．53％）和休息（32．45％）行为较多,站立（6．24％）,摄食（10．13％）,社会（8．36％）和其他（5．29％,包括饮水,排遗,修饰等）行为较少;（2）不同季节的活动规律相似,运动,摄食,站立和社会行为在上午和下午各有1个高峰期,休息在中午有1个高峰期,运动和行为在存,冬季明显比春,秋季增多。将上述结果与笼养和野生东北虎的进行了比较,并提出了在今后的野化训练中应采取的措施。     

Biology, fisheries, and conservation of sturgeons and paddlefish in China

This paper reviews five of the eight species of acipenseriforms that occur in China, chiefly those of the Amur and Yangtze rivers. Kaluga Huso dauricus and Amur sturgeon Acipenser schrenckii are endemic to the Amur River. Both species still support fisheries, but stocks are declining due to overfishing. Acipenseriformes of the Yangtze River are primarily threatened by hydroelectric dams that block free passage to spawning and feeding areas. The Chinese paddlefish Psephurus gladius now is rare in the Yangtze River system, and its spawning activities were severely limited by completion of the Gezhouba Dam in 1981. Since 1988, only 3–10 adult paddlefishes per year have been found below the dam. Limited spawning still exists above the dam, but when the new Three Gorges Dam is complete, it will further threaten the paddlefish. Artificial propagation appears to be the only hope for preventing extinction of P. gladius, but it has yet to be successfully bred in captivity. Dabry's sturgeon A. dabryanus is a small, exclusively freshwater sturgeon found only in the Yangtze River system. It is concentrated today in reaches of the main stream above Gezhouba Dam. The fishery has been closed since 1983, but populations continue to decline. Acipenser dabryanus has been cultured since the 1970s, and holds promise for commercial aquaculture; availability of aquacultural methods offers hope for enhancing natural populations. The Chinese sturgeon A. sinensis occurs in the Yangtze and Pearl rivers and seas of east Asia. There is still disagreement about the taxonomy of the Pearl and Yangtze River populations. The Yangtze River population is anadromous. Adults begin spawning at about age 14 years (males) and 21 years (females), and adults spend over 15 months in the river for reproduction. Spawning sites of A. sinensis were found every year since 1982 below the Gezhouba Dam, but it seems that insufficient suitable ground is available for spawning. Since 1983, commercial fishing has been prohibited but more measures need to be taken such as establishing protected areas and characterizing critical spawning, summering and wintering habitats.     

北京地区黄檗分布与环境因子的关系

黄檗（Phellodendron amurense Rupr.）为我国二级重点保护野生植物,在北京地区黄檗多散生于阔叶林中,数量稀少。为了解北京地区黄檗分布与环境因子的关系,促进种群扩繁,在北京百花山、松山和雾灵山自然保护区共设置了12个20 m×20 m的样地,利用CCA分析方法对不同地点黄檗的生长分布状况与海拔、坡度、坡向、郁闭度、土壤pH值、碱解氮和土壤有机质等11个环境因子的关系进行了分析。结果显示,CCA排序第一轴主要反映了海拔、郁闭度和坡度的变化,第二轴主要反映了有机质含量、碱解氮含量、pH值和坡向的变化,其中海拔、碱解氮和土壤有机质是影响黄檗生长分布的重要环境因子,低海拔、低碱解氮含量以及土壤有机质高的地段适宜黄檗分布。对影响黄檗分布的环境因子进行定量分离,结果发现环境因子对黄檗样地物种分布的解释能力为84.5%,显示出较好的排序效果,黄檗分布点受人为干扰较少,其所在植物群落与环境保持了良好的对应关系;环境因子与物种分布呈显著相关（P=0.03）,表明CCA排序结果可以解释环境因子对物种分布的影响程度。     

Insect ovipositions on aquatic plant leaves <Emphasis Type="Italic">Quereuxia</Emphasis> from the Upper Cretaceous of the Amur region

New form taxa of insect ovipositions on aquatic plant leaves Quereuxia from the Campanian locality of Udurchukan (Amur Region) are described. Endophytic ovipositions Paleoovoidus flabellatus sp. nov. and P. arcuatus sp. nov. do not differ in shape from ovipositions of recent damselflies. Exophytic ovipositions Palaexovoidus ovoideus gen. et sp. nov., P. catenulatus sp. nov., P. multus sp. nov., and P. amplus sp. nov. belong to insects that develop in the water, probably dragonflies of the suborder Anisoptera. A new family Palaexovoididae fam. nov. is erected.     

Isolation of microsatellite loci from the endemic and endangered Adriatic sturgeon (<Emphasis Type="Italic">Acipenser naccarii</Emphasis>)

With the aim of elaborating a breeding plan on a captive stock of the highly endangered Adriatic sturgeon (Acipenser naccarii), a total of 10 polymorphic microsatellite loci were isolated from an enriched library. The results of cross amplification of additional 8 loci previously isolated from A. oxyrinchus, A. fulvescens and Scaphyrinchus platorhynchus are also reported. Given the tetraploid condition of the species the genetic variability was estimated basing on the number of alleles per individuals and the average band sharing.     

半圈养条件下东北虎繁殖期的行为时间分配

1998年 10月～ 2 0 0 0年 10月在黑龙江东北虎林园 ,采用随机取样法和瞬时扫描取样法对繁殖期东北虎的行为进行了研究。结果表明 ,在繁殖期的不同阶段东北虎的行为发生较大的变化。在发情交配期雌雄虎的时间分配相似 (P >0 0 5 ) ,均将最多的时间用于运动 ,用于休息的时间较少 ,用于发情交配和其它行为的时间较多。雌虎在妊娠期较多的时间用于休息和运动 ,取食、站立、社会和其它行为的时间均较少 ;产仔期最多的时间用于休息 ,其次是运动 ,用于产仔和其它行为的时间较多 ,用于取食的时间最少 ;哺乳期最多的时间用于休息 ,其次是哺乳和运动 ,用于取食和其它行为的时间较少。活动规律方面 ,各种行为在强度、出现和持续的时间上存在较大差异。单因素方差分析表明 ,在繁殖期的不同阶段雌性东北虎的休息和运动存在极显著差异 (P <0 0 0 1) ,取食存在显著差异 (P <0 0 5 ) ,只有其它行为不存在显著差异(P >0 0 5 )。 10 0日龄内幼虎用于休息的时间最多 ,其次是运动和取食 ,其它行为的时间最少。     

Comparative phylogeography of salmonid fishes (Salmonidae) reveals late to post-Pleistocene exchange between three now-disjunct river basins in Siberia

Abstract. We use a comparative phylogeographical framework to evaluate the hypothesis of hydrological exchange during the Pleistocene among the now disjunct Lena, Amur, and Enisei basins in Siberia, and to provide evidence on the causal mechanism of their present day faunal dissimilarities. Approximately 600 bases of the mitochondrial control region were sequenced in five distinct lineages among three genera of salmonid fishes, Hucho, Brachymystax and Thymallus. All three basins were fixed for divergent (2–5.4%) lineages of Thymallus whereas a single shared haplotype was present in all three basins for Hucho taimen ( Pallas, 1773 ) and one shared haplotype between the Lena and Amur basins out of a total of five for blunt‐snouted and one out of five for sharp‐snouted Brachymystax lenok ( Pallas, 1773 ). For both blunt‐ and sharp‐snouted lenok the haplotypes found within each basin did not form clades, so no relationship between genotypes and geographical occurrence was found. Our data support relatively recent hydrological mixing of the major river drainage systems in eastern and far‐eastern Siberia, congruent with the hypothesis of large‐scale palaeo‐hydrological exchange stemming from glacial advance, retreat and melting during Pleistocene climate fluctuations. Furthermore, these results in conjunction with a comparison of overall faunal composition suggest that environmental differences rather than historical contingency may be responsible for the faunal dissimilarities of the Amur, Lena, and Enisei river basins.     

中华鲟产卵场平面平均涡量计算与分析

采用Delft3D-Flow模型对葛洲坝下游中华鲟产卵场河段进行流场模拟,用实测资料对模型进行验证和参数率定,模拟结果和实测资料基本吻合.在此基础上,阐述了平面平均涡量计算方法,利用模拟所得流速场,通过计算得到中华鲟产卵场河段区域平面平均涡量强度分布.计算结果表明,鱼卵密集区的平面平均涡量为1.38×10-3～1.64×10-3s-1,说明中华鲟产卵对区域平面涡量强度有偏好选择,这种选择具有生物学意义.可为今后保护中华鲟产卵场水力学环境提供理论支持和参考.     

Molecular cloning and functional analysis of Chinese sturgeon (Acipenser sinensis) growth hormone receptor

A full length cDNA encoding the growth hormone receptor (GHR) of Chinese sturgeon was cloned in order to investigate the mechanism of growth hormone in regulating the growth of Chinese sturgeon. The open reading frame of the cloned Chinese sturgeon growth hormone receptor (csGHR) cDNA encodes a trans-membrane protein of 611 amino acids containing all the characteristic motifs of GHR. By sequence alignment, substitutions of amino acid residues highly conserved in other species were identified. Using the CHO cell culture system, the function of csGHR and the biological significance of the amino acid substitution in csGHR were examined. The promoter of serine protease inhibitor 2.1 (Spi2.1) was trans-activated upon stimulation of seabream GH (sbGH) in the csGHR-expressing CHO cells. Furthermore, CHO cells stably expressing csGHR were stimulated to proliferate by sbGH. In agreement with our previous report, Chinese sturgeon growth hormone-binding protein (csGHBP) was detected in the culture medium of CHO cells stably expressing csGHR. Mutation of Asp residue in the ligand binding motif in csGHR to Glu significantly enhanced csGHR’s biological function, whereas mutation of Asp residue to Ala decreased its biological function. The results demonstrated that the cloned csGHR was of full biological function and the csGHBP could be generated through proteolysis of csGHR. These findings might provide new insights into thoroughly understanding the regulatory mechanism of Chinese sturgeon growth.