长江东流河道整治对长江江豚种群数量的影响

长江江豚是生活在长江中下游的濒危水生哺乳动物,通常活动在江心洲和浅水缓滩附近。航道整治改变了鱼类栖息活动的水文环境,也给豚类生存带来负面影响。本文根据长江东流河道整治施工前和施工后各3 次野外考察资料,分析了3 种流态中江豚的数量与群结构。结果表明,该工程实施前江豚主要栖息活动在边滩的分离区,其次在洲头的分流区。工程实施后,整治江段的江豚种群数量年下降率达8. 9% 。江豚在分流区活动已消失,在分离区集群规模较小,且在流态之间移动增大。本文研究结果也提示长江江豚就地保护难度越来越大,从长江干流中把长江江豚迁入故道中是一件刻不容缓的工作。     

Mitochondrial phylogeography and population history of finless porpoises in Sino‐Japanese waters

Phylogeographical patterns of intraspecific variation can provide insights into the population‐level processes responsible for speciation and yield information useful for conservation purposes. In the present study, three hundred and forty‐five base pairs of the mitochondrial DNA control region were sequenced to analyse the genetic diversity, population structure and history, and phylogeography of finless porpoises (Neophocaena phocaenoides) in Chinese and Japanese waters of the North Pacific. Nucleotide and haplotype diversities were 0.44% and 0.79 ± 0.01 for Chinese and Japanese waters, respectively, but varied significantly among populations. Analysis of molecular variance showed a high level of genetic structure between populations (Φ_ST = 0.61, P < 0.001; F_ST = 0.52, P < 0.001). Eleven of 18 haplotypes were restricted to a single population, common haplotypes were found in two to four populations, but no haplotype was found throughout Sino‐Japanese waters, suggesting multiple colonization events followed by limited gene flow. The inferred age of demographic expansion was from the end stage of the last ice age to the Holocene. No obvious phylogeographical pattern was revealed, including between saline and fresh water populations. A low level of genetic diversity for each population and high among‐population differentiation in haplotype frequency were revealed, which suggest a role for random genetic drift, recent demographic bottlenecks, and reduced or limited gene flow in these populations. Some conservation considerations, with special reference to the unique Yangtze population, are discussed. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 95 , 193–204.     

Seasonal changes in the local distribution of Yangtze finless porpoises related to fish presence

The Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis) is an endangered freshwater porpoise subspecies unique to the Yangtze River basin. Seasonal variations in local distribution of the animal, as well as fish presence, sand dredging, ship navigation, and bridges were examined as potential factors affecting the occurrence of the animals. Passive acoustic surveys were performed regularly from May 2007 to August 2010, near the conjunction of the Yangtze River and Poyang Lake. The distribution of the porpoises was seasonally site‐specific. In May and August, the animals were detected more often at river junctions than in the lake, but vice versa from November to February. The rate of the porpoise detection was significantly higher in areas of fish presence than in areas of absence. The number of porpoises detected did not differ significantly between the sand dredging operation and the prohibition period (in 2008), although the number of vessels obviously declined in 2008. Ship traffic and bridges also did not appear to affect the presence of porpoises. These results showed the relative importance of the various environmental factors, which is important for conservation of not only Yangtze finless porpoise but also endangered isolated cetaceans.     

Yangtze finless porpoises along the main channel of Poyang Lake,China: Implications for conservation

Poyang Lake is the largest freshwater lake in China and flows into the Yangtze River. It is a traditional habitat for the endangered Yangtze finless porpoise, which has not been well investigated. To reveal the distribution of the porpoise in Poyang Lake, 12 passive acoustic surveys were conducted along 123 km of the main channel of the lake during different seasons (spring transition season, wet season, autumn transition season, and dry season) from 2008 to 2012. We counted the number of phonating porpoises encountered and calculated the detection rate (encountered individuals detected per kilometer). The median porpoise detection rates ranged from 0 to 0.65 individuals per kilometer during the different surveys. The highest median detection rate of 0.50 was detected in the autumn transition season. The seasonal shrinking of the lake during the dry season may cause a concentration of porpoises in the narrow channels and a high incidence of collisions with cargo ships and fishing boats. Conservation actions should be focused on the main channel of the lake during the dry and transition seasons. In addition, the expansion of the existing reserve to include areas with high porpoise detection rates is necessary.     

北部湾沙田水域中华白海豚和江豚的同域分布格局及时空变化

北部湾是中华白海豚和江豚的重要分布区,但是对该水域两物种的分布格局及时空变化的研究却比较少,也不清楚这两个物种分布区是否有重叠。2003 ～ 2004 年与2011 ～2012 年期间,我们在北部湾沙田水域进行了船只调查,总计航程4 876.8 km,收集了两个物种空间分布的数据。结果表明,2003 ～ 2004 年仅发现中华白海豚,2011 ～2012 年则同时发现了中华白海豚和江豚。与2003 ～ 2004 年4 ～ 5 月相比,中华白海豚在2011 年4 ～ 5 月份的遇见率明显增加(0.152 vs 0. 028 头次/km)。中华白海豚的MCP、95% FK 家域和50% FK 核心域面积分别为162. 6 km² 、271. 35 km² 和56.78 km² ,2011 ～ 2012 年50% FK 核心家域有所扩大且东移。江豚的MCP、95% FK家域和50% FK 核心域面积分别为97.21 km² 、318.72 km² 和38.18 km² 。江豚主要分布于中华白海豚的外围远岸水域,同时两个物种的分布区有小部分重叠。基于多种因素的分析,我们推测,江豚可能存在季节性迁移以及中华白海豚对河口区有明显的偏好,可能是造成它们分布格局不同的原因。     

人工饲养长江江豚的同性性行为和自慰行为

雌雄性之间的性行为对鲸类的生存和繁衍有着极其重要的意义。然而不具有繁殖功能的同性性行为和自慰行为在多种鲸类中存在。因此对鲸类非繁殖性性行为研究,将有助于深入认识该物种性行为特点和规律,并解决室内饲养可能存在的问题以及促进可控性人工繁殖的成功。本研究以人工饲养的7头长江江豚为研究对象,定义并描述了14种性行为。其中,同性之间的性行为定义为同性性行为,雌雄个体单独的性行为定义为自慰行为。雄性同性性行为发现于所有定义的性行为中,但雌性同性性行为仅在7种性行为中观察到。同性性行为（3633次）占总性行为（5563次）的65.31%,自慰行为（254次）占4.57%。同性性行为中,雄性之间的同性性行为（3438次,94.63%）远多于雌性同性性行为（195次,5.37%）。两头有父子关系的江豚（阿福和淘淘）之间的雄性同性性行为最多（1921次,55.88%）,雄性江豚之间的同性性行为可能存在结盟竞争关系或教育练习作用。两头青少年雌豚（F7和F9）之间的同性性行为最活跃（117次,60.00%）,雌性江豚之间的同性性行为很可能具有结伴交流的功能。     

Diurnal changes of behavior and respiration of Yangtze finless porpoises (Neophocaena phocaenoides asiaeorientalis) in captivity

A preliminary study was carried out to investigate diurnal changes of behavior of three, one adult male, one adult female, and one juvenile female, Yangtze finless porpoises (Neophocaena phocaenoides asiaeorientalis) in captivity. The respiration and behavior of the porpoises were recorded for 222 hr across 42 days. Behavioral data were recorded for eight general categories: aerial display and fast swimming, begging for fish, playing, nonsexual socializing, sexual behavior, resting, rubbing, and miscellaneous (i.e., other behaviors not included in the above categories). Each behavioral category was scored using one‐zero sampling with 10‐min intervals. The adult male showed shorter mean respiratory intervals at night (19:00–7:00 h), whereas the mean respiratory intervals of the females were shorter during the day (7:00–19:00 h). Begging for fish of all individuals, playing of the juvenile female, nonsexual socializing, and miscellaneous behavior of the adult female and resting of the male were observed more easily in the day, and aerial display and fast swimming of the adults and resting of the females were observed more easily at night. No significant diurnal difference was found, however, in the remaining categories of each individual. Each of the three porpoises therefore showed a distinct diurnal pattern, but none was obviously more active in the daytime than during the nighttime. Results suggest that daytime‐only feeding schedules may be insufficient to meet the energetic needs of marine mammals that show a 24‐hr activity cycle, and that nighttime feeding may be a worthwhile addition to husbandry routines. Zoo Biol 0:1–11, 2005. © 2005 Wiley‐Liss, Inc.     

定量评估豢养长江江豚个体间的优势关系

2000年1—4月和2000年4月—2002年4月,分别连续3个月和2年观察了中国科学院水生生物研究所白鱀豚馆6头长江江豚（3雌3雄,8个不同组合群）个体间发生的3种交互关系,即接近—逃开、接近—接触和接近—尾鳍击打。在累计8,162min的观察时间内,共观察到这些交互关系1,685次。本研究将江豚个体间发生的这3种交互关系作为个体间优势关系的指示,并分别给交互双方赋予不同的分值,采用优势比分矩阵方法定量分析了江豚个体之间的优势关系。结果表明江豚群体内存在优势关系。同性别个体之间,优势关系与年龄和饲养时间有关,年龄大的个体比年龄小的个体具有优势,饲养时间短的个体比饲养时间长的个体具有优势。但是,异性成年个体之间,优势关系通常是可变的。     

Physiological responses to capture and handling of free-ranging male Yangtze finless porpoises (Neophocaena phocaenoides asiaeorientalis)

We captured free-ranging male Yangtze finless porpoises over three seasons and assayed leukocytes and serum biochemistry to investigate physiological responses to the capture and handlings. Serum thyroid hormones (THs) declined sharply in those porpoises compared with hormone variation in a captive male finless porpoise. Hypernatremia and hypokalemia were also significant in the free-ranging animals suggesting that conservation of serum sodium might be acutely vital for this freshwater subspecies. The animals captured in spring showed more significant neutrophilia and eosinopenia than those captured in autumn suggesting that they may be more affected by capture during the breeding season. Furthermore, physical examination of porpoises when out of the water was apparently stressful, particularly when they were kept out of the water for longer periods. However, an increase in circulating THs may be an adaptive response to accommodate these short-term stresses.     

用微卫星指纹识别天鹅洲保护区长江江豚个体

DNA指纹个体识别技术是保护遗传学研究中的一种非常重要的手段。为了准确地识别天鹅洲保护区中的每一头长江江豚以开展保护遗传学及其它相关研究 ,并实施有效的种群管理 ,本研究应用 4个微卫星座位初步构建了该群体的DNA指纹图谱 ,并利用此图谱成功地对不同时期在保护区捕获的江豚进行了个体识别研究。结果显示微卫星指纹技术是一种适用于长江江豚个体识别研究的可靠手段     

One-sided infections by intestinal parasites in two sympatric porpoises bycaught from the Nemuro Strait of Hokkaido,Japan

Due to the difficulties and limitations associated with field sampling of marine mammals, quantitative surveys on their parasites are still scarce in Japan. We here report the infection statuses of intestinal parasites in harbor porpoises (n = 34) and Dall's porpoises (n = 10), bycaught between 2014 and 2018 by a bottom set-net fishery in the northern part of the Nemuro Strait, Japan. Necropsies of the harbor porpoises recovered one digenean, Synthesium nipponicum, and two acanthocephalans, Corynosoma sp. and Bolbosoma sp.; no infection was observed in the Dall's porpoises. The dominant parasites were Corynosoma sp. and S. nipponicum, with a prevalence of 73.53 and 64.71% and a mean abundance of 43.88 and 7.38 individuals, respectively. Although the two porpoise-species have a sympatric distribution in this narrow strait, the findings support the existence of trophic-link dependences, which can differentially affect vulnerability to these parasites.     

Suckling behavior and its development in two Yangtze finless porpoise calves in captivity

We focally observed the suckling behavior of two Yangtze finless porpoise calves, C05 and C07, in captivity. Between 15 and 730 days postpartum of C05 and between birth and 30 days postpartum of C07, 286.3 (1.9 ± 0.4 hr/day (mean ± standard deviation), n = 148 days) and 18.3 hr (2.0 ± 0.5 hr/day, n = 9 days) of video footage were recorded, in which 429 and 111 suckling events were observed, respectively. We found that the calves made their initial suckling attempts after repeated stroking of the mother's body with their rostrums. The suckling duration was 4.4 ± 1.8 sec and 4.8 ± 2.4 sec, respectively. Before suckling, the calves swam under the mother's genital region (99.1% of number of event, respectively). During suckling, the mother generally turned sideways to facilitate the calves' suckling (80.7 and 76.6%, respectively). The calves almost equally used the two mammary slits [52.2% (left) and 47.8% (right), and 44.1% (left) and 55.9% (right), respectively]. The frequency and proportion of time C05 spent suckling continuously decreased to zero by 483 days postpartum. The two variables for C07 increased following birth, to a peak at 16 days postpartum, and then decreased continuously until 30 days postpartum. We discuss the possible implications of these observations for the management and conservation of this endangered cetacean.     

Comparison of two histological techniques for age determination in small cetaceans

Age estimation in odontocetes is based on counts of growth layer groups (GLGs) deposited in recording structures such as teeth. Generally, tooth sections are obtained using a cryostat microtome. However, some researchers prefer obtaining thin sections using a traditional paraffin microtome. Little information is available on the application of this technique to dolphin teeth. Our main aim was to investigate if the paraffin technique can be a viable alternative. We considered whether estimated age would be affected by preparation technique, staining method, and section thickness, while controlling for effects of species, body length, and sex. We also analyzed whether the staining method would affect readability of GLGs and age reading variability. Teeth from 86 individuals (representing seven species) were used, but not all were prepared using both techniques because sufficient teeth were not available in all cases. Although the staining method had significant effects on the estimated age using both techniques, the variability of GLG counts was small and appeared to be similar for both techniques. Using Mayer's hematoxylin stained sections of 8 μm thickness, good agreement of ages was obtained from both techniques, with more preparations classified as "good quality" for the paraffin technique. Mayer's hematoxylin provided the best contrast of the GLGs when using the paraffin technique. We conclude that the paraffin technique is viable and represents a cost-effective alternative to a cryostat microtome when preparing cetacean teeth for age determination.     

长江和畅洲江段大型船舶的噪声特征及其对长江江豚的潜在影响

长江航运业的快速发展导致长江中船舶数量激增,相应的水体噪声污染可能对同水域的长江江豚（Neophocaena asiaeorientalis asiaeorientalis）产生一定的负面影响,本研究采用宽频录音设备对长江和畅洲北汊非正式通航江段的各类常见大型船舶（长>15m且宽>5m）的航行噪声进行了记录,并分析其峰值-峰值声压级强度（SPLp-p）和功率谱密度（PSD）等。结果表明,大型船舶的航行噪声能量分布频率范围较广（>100kHz）,但主要集中于中低频（<10kHz）部分,各频率（20Hz~144kHz）处的均方根声压级（SPLrms）对环境背景噪声在该频率处的噪声增量范围为3.7~66.5dB。接收到的1/3倍频程声压级（TOL）在各频率处都大于70dB,在8~140kHz频段内都高于长江江豚的听觉阈值。说明大型船舶的航行噪声可能会对长江江豚个体间的声通讯及听觉带来不利影响,如听觉掩盖。     

High level population differentiation of finless porpoises (Neophocaena phocaenoides) in Chinese waters revealed by sequence variability of four nuclear introns

In the present study, sequence variations at four nuclear introns which were respectively from the parathyroid hormone-like (PTH) gene, isolate Pdalz1692 interferon (IFN) gene, peripherin-like (RDS) gene, and tyrosine kinase receptor-like (KIT) gene, were examined to analyze genetic diversity and population structure of the finless porpoise (Neophocaena phocaenoides) in Chinese waters. High among-population differentiation was revealed, with a significant genetic structure between populations (PTH: F(ST) = 0.29, P < 0.001; IFN1@: F(ST) = 0.23, P < 0.001; RDS: F(ST) = 0.12, P < 0.001; KIT: F(ST) = 0.16, P < 0.001) shown by the analysis of molecular variance. Although common haplotypes accounted for more than one half of all samples examined, many haplotypes were found to be population-specific. The Tajima's D, Fu's tests and mismatch distributions all suggested a recent colonization and population expansion of finless porpoises in Chinese waters. In view of special reference to the conservation priority of the Yangtze finless porpoises, special protection measures must be taken urgently for this population.     

长江江豚TRAIL基因的克隆、体外表达及生物学功能分析

构建可溶性肿瘤坏死因子相关凋亡诱导配体(TRAIL)基因的表达体系,研究其蛋白表达产物对肿瘤细胞凋亡的影响,为以后江豚免疫系统的研究奠定基础。通过RT-PCR技术从江豚Neophocaena phoconoides血液总RNA中反转录扩增出肿瘤坏死因子相关凋亡诱导配体(简称fTRAIL)的全长cDNA序列,并将fTRAIL的胞外可溶性(简称fsTRAIL)片段连接入表达载体pET43.1a中,在大肠杆菌BL21(DE3)中表达并纯化,Western blotting对产物Nus-His-fsTRAIL蛋白进行鉴定。体外用MTT法、台盼蓝拒染法及流式细胞术检测Nus-His-fs TRAIL蛋白对Jurkat细胞和HeLa细胞的影响。成功构建了fTRAIL胞外可溶性片段(简称fsTRAIL)与pET43.1a组成的表达载体,并获得Nus-His-fsTRAIL蛋白。体外实验表明,Nus-His-fsTRAIL蛋白能够以剂量依赖的方式抑制Jurkat和HeLa细胞的增殖并诱导其凋亡。Nus-His-fsTRAIL表达产物具有对Jurkat和HeLa细胞体外抗肿瘤活性的作用。     

Pattern of genetic variation of yellow catfish Pelteobagrus fulvidraco Richardso in Huaihe river and the Yangtze river revealed using mitochondrial DNA control region sequences

Genetic variability and population genetic structure of the yellow catfish Pelteobagrus fulvidraco Richardso in the Huaihe river and the Yangtze river was examined with a 810-bp of the mitochondrial DNA control region. A total of 70 haplotypes were identified from 145 samples, which were characterized with high haplotype diversity (h = 0.9832 ± 0.0041) but low nucleotide diversity (π = 0.0415 ± 0.0201). The analysis of molecular variance and phylogenetic reconstructions detected significant geographic structure between Huaihe river and Yangtze with F_ST = 0.1183 (P = 0.0000). Neighbor-joining (NJ) phylogenetic analyses identified two distinct clades (bootstrap support 99 %). The medium joining network drawn using the complete data set was reticulated and also distinctly split the 70 haplotypes into two groups corresponding to those of the NJ tree. Departures from neutrality were not significant for the Huaihe river and the Yangtze river Pelteobagrus fulvidraco, concordant with the observed multimodal mismatch distributions (P > 0.05), which suggested that the effective size of this species has been large and stable for a long period. The question about the existence of significant genetic differentiation for Pelteobagrus fulvidraco in the Yangtze river and Huaihe river basins remains to be further studied with molecular nuclear markers and larger sample sizes from throughout the river basins.