西藏浪错兰格湖裸鲤的年龄与生长

2017年7月—2018年5月,于西藏自治区昂仁县浪错采集268尾兰格湖裸鲤Gymnocypris chui开展种群年龄结构和生长特征研究。结果显示:雌、雄鱼体长与体质量的关系式分别为W♀=2.03×10-2L2.822(n=134,R2=0.969)、W♂=2.52×10-2L2.738(n=105,R2=0.966)。通过观察微耳石,发现样本由1~23龄组成;采用VonBertalanffy生长方程拟合雌、雄鱼体长、体质量生长方程:Lt♀=34.239[1-e-0.136(t+0.11)]、Wt♀=434.42[1-e-0.136(t+0.11)]2.822;Lt♂=32.201[1-e-0.136(t+0.287)]、Wt♂=338.8[1-e-0.136(t+0.287)]2.738;拐点年龄分别为7.52龄和7.12龄,对应体长分别为22.12cm和20.45cm,体质量分别为126.59g和97.71g。初步研究表明,兰格湖裸鲤生长慢、体型小,种群被破坏后不易恢复,亟待开展资源评估及保护工作。     

西藏浪错兰格湖裸鲤种群繁殖生物学特征

2017年7月至2018年6月,于西藏自治区昂仁县浪错采集兰格湖裸鲤(Gymnocypris chui)307尾,开展种群繁殖生物学研究。结果显示,浪错兰格湖裸鲤在3～5月性成熟系数较高。雌性最小性成熟个体年龄为7龄,体长217mm,体重122.68g,成熟系数为3.92%;雄性最小性成熟个体年龄为6龄,体长198 mm,体重91.93 g,成熟系数为3.34%。其平均成熟卵径为2.18 mm,卵径分布为单峰型。绝对繁殖力为862～8 933粒/尾,平均绝对繁殖力为(2 885±2 765)粒,相对繁殖力为7～43粒/g,平均相对繁殖力为(15±11)粒/g。绝对繁殖力与体长和体重呈显著正相关,相对繁殖力与体长、体重的相关性不显著。繁殖群体性比(♀︰♂)为1︰0.967,符合1︰1比例。     

西藏羊卓雍错高原裸鲤肠道寄生蠕虫的群落生态

为研究西藏羊卓雍错Yamdrok Lake高原裸鲤肠道寄生蠕虫的群落生态,探索寄生虫与西藏高原环境和独特的鱼类宿主三者之间的相互关系,以肠道寄生蠕虫为对象,于2020年7月对180尾高原裸鲤Gymnocypris waddellii [雌性120尾,雄性60尾,全长22.20—49.20 cm,平均全长(36.76±4.18) cm,体重77.3—896.7 g,平均体重(425.92±148.27) g]进行了剖检,对群落结构和种间关系等群落生态进行了分析。羊卓雍错高原裸鲤肠道寄生蠕虫群落由5个物种构成,分别为聂氏似短节绦虫Parabreviscolex niepini、对盲囊线虫Contracaecum eudyptulae、束首线虫未定种Streptocara sp.、新棘吻虫未定种Neoechinorhynchus sp.和异肉吸虫未定种Allocreadium sp.。感染率从高到低依次为新棘吻虫未定种、聂氏似短节绦虫、异肉吸虫未定种、对盲囊线虫和束首线虫未定种。平均丰度从高到低依次为聂氏似短节绦虫、新棘吻虫未定种、束首线虫未定种、异肉吸虫未定种和对盲囊线虫。群落的Marga...     

长江宜宾江段铜鱼属鱼类种间食物关系

采用碳、氮稳定同位素技术对2012年4-5月长江宜宾江段铜鱼和圆口铜鱼的食物组成进行了分析,并利用多元统计分析方法探讨了铜鱼和圆口铜鱼种间食物关系,包括饵料相似性指数、重叠系数及2种鱼的摄食器官形态差异对食物组成的影响.结果表明:1)铜鱼的δ13C和δ15N变化范围分别为-21.15‰～-20.31‰和9.67‰～ 10.21‰,为偏动物性的杂食性鱼类;圆口铜鱼的δ13C和δ15N分别为-23.30‰～-21.18‰和7.40‰～ 9.21‰,相对铜鱼为偏植物性的杂食性鱼类,铜鱼和圆口铜鱼均与传统肠含物分析的结果存在一定的差异;2)两种鱼的食物相似性指数和食物重叠系数分别为78.7％和55.6％;3)主成分分析(PCA)表明,铜鱼和圆口铜鱼摄食器官形态特征存在一定的差异.长江宜宾江段铜鱼和圆口铜鱼种间竞争不激烈,作为向家坝蓄水前最后一次对长江宜宾江段铜鱼和圆口铜鱼食性及种间食物关系的调查,研究结果可为分析向家坝蓄水对宜宾江段鱼类营养结构的影响提供数据参考.     

长江口水域中华鲟幼鱼与6种主要经济鱼类的食性及食物竞争

根据2004年6月至8月和2005年6月至8月在长江口崇明岛东滩水域插网所获取的鱼类样本,对东滩水域中华鲟(Acipenser sinensis)幼鱼和其它6种主要经济鱼类的食性、食物竞争状况进行了研究。结果表明:中华鲟、窄体舌鳎(Cynoglissus gracilis)为底栖生物食性;中国花鲈(Lateolabrax maculatus)为游泳生物食性;刀鲚(Coilia ectenes)和凤鲚(Coilia mystus)为浮游动物食性;鲻(Mygil cephalus)和鮻(Liza haematochiela)为腐屑(有机碎屑)食性。中华鲟幼鱼及6种主要经济鱼类食性按照相对重要性指标(IRI)大小排列:中华鲟(IRI):鱼类端足类多毛类蟹类;窄体舌鳎(IRI):虾类瓣鳃类鱼类;中国花鲈(IRI):鱼类虾类等足类蟹类;刀鲚(IRI):糠虾类虾类桡足类鱼类;凤鲚(IRI):糠虾类桡足类虾类鱼类;鲻(IRI):有机碎屑底栖藻类瓣鳃类桡足类;鮻(IRI):有机碎屑底栖藻类瓣鳃类桡足类。长江口崇明东滩中华鲟与6种经济鱼类饵料重叠系数显示,中华鲟与窄体舌鳎的饵料重叠系数达到了0.4,而与其余5种鱼类的饵料重叠系数均小于0.12。这表明窄体舌鳎对中华鲟幼鱼的食物有一定的竞争力,其余5种鱼类对中华鲟幼鱼的食物竞争强度较低。     

荒漠草原蝗虫营养生态位及种间食物竞争模型的研究

以宁夏荒漠草原 1 2种蝗虫为对象 ,对荒漠草原蝗虫的营养生态位和种间食物竞争模型进行了研究 .采用嗉囊内含物分析技术分析了 1 2种蝗虫的取食特性和食物利用谱 ,并根据嗉囊内含物的分析结果 ,定量研究了蝗虫的营养生态位重叠和宽度 .依据生态位分化的特点 ,1 2种蝗虫可划分为 4个不同营养需求类群 :杂草取食者、杂草 禾草取食者、禾草 杂草取食者、禾草取食者 .通过蝗虫的取食频率、生物量以及种群密度 ,提出了蝗虫种间食物竞争力评估模型 ,对 1 2种蝗虫种间食物竞争的作用力进行了讨论 .     

川西北高原裸头科绦虫调查及双宫带属一新种记述

在四川省西北部高原地区检查野生草食动物7种、208只(头),感染有绦虫成虫的48只(头),其中感染裸头科绦虫的6种,34只(头),感染率18.48％,共获得裸头绦虫5属、8种。本文首次报道我国寄生于啮齿类的巨首无摄腺绦虫及新种道孚双宫带绦虫的形态。     

高原鳅属两亲缘种DNA指纹图谱及一新种的描述（鲤形目：鳅科）

用ＤＮＡ指纹技术和形态特征分析方法对高原鳅属两个亲缘种鱼类的遗传关系进行比较分析，结果表明两者遗传性状差异明显，且稳定，与形态性状研究结果一致，据此认为这两种鱼类应是两个独立的物种，其中一种为新种ＴｒｉｐｌｏｐｈｙｓａｐｏｌｙｆａｓｃｉａｔａＤｉｎｇｓｐ．ｎｏｖ，并进行描述。     

花背蟾蜍繁殖种群食物多样性及营养生态位的研究

作者于１９９５年４～５月份在长春市调查了花背蟾蜍繁殖种群不同繁殖时期的食性,并通过食物多样性和营养生态位对食性变化进行了分析。结果表明,繁殖种群繁殖后的食物多样性指数、营养生态位宽度较繁殖期为大;繁殖期和繁殖后的食物百分率相似性指数及营养生态位重叠值小,而食物百分率相异性及营养生态位分离值大。繁殖期雄体的食物多样性指数及营养生态位宽度均大于雌体,繁殖后雌体的食物多样性指数及营养生态位宽度均大于雄体,雌雄个体间的食物百分率相异性指数及营养生态位分离值小。摄食活动性受繁殖影响,并随繁殖结束而增强。     

沙区人工固沙植物的种间生态位关系与系统模拟研究

在沙坡头沙区人工植被群落区,采用空间序列代替时间序列,并以演替时间为生态位维度,通过定量分析物种的生态位体积和生态位重叠,研究沙区人工植物群落演替过程中群落各组分种对资源的利用能力、种间生态相似性及竞争机制。基于干扰作用的机理分析,组建具有干扰作用的竞争系统模型,并进行数值模拟研究。结果表明:人工栽植的灌木花棒、柠条和半灌木油蒿的生态位体积值在时间尺度上呈现先增加而后减少的变化趋势;天然1年生草本各植物种则呈现持续增加的趋势。灌木、半灌木种之间、草本植物与草本植物之间的生态位重叠值较大,其中花棒与油蒿、虎尾草与雾冰藜之间的生态位重叠值分别为0.719 2和0.862 2,这表明二者之间有较大的生态相似性,从而在演替过程中具有较强的竞争作用;而半灌木油蒿与各草本植物之间的生态位重叠值很小,它们能够实现稳定共存。系统模拟结果表明:在群落竞争系统中,干扰强度适中时,弱竞争种具有较强侵占率,可以排斥强竞争者,不同干扰强度下系统可以产生多个可能的竞争结果,即诱发出群落不同的稳定状态,这与样区调查结果是一致的。     

Validation of daily increment formation in otoliths for Gymnocypris selincuoensis in the Tibetan Plateau,China

Daily increment validation in fish otolith is fundamental to studies on fish otolith microstructure, age determination and life history traits, and thus is critical for species conservation and fishery management. However, it has never been done for Schizothoracine fish, which is the dominant component of fish fauna in the Tibetan Plateau. This study validated the daily increment formation of Gymnocypris selincuoensis, as a representative of Schizothoracine fish, by monitoring the growth of hatchery‐reared larvae group and wild‐caught post‐yolk‐sac larvae group under controlled experiments. The results from monitoring the hatchery‐reared larvae group showed that sagittae and lapilli were found in yolk‐sac larvae, and formed 5–7 days before hatching, but asterisci were not found until 11 days post‐hatching. The first increment in sagittae and lapilli was formed in the first day after hatching. The daily periodicity of increment formation was examined and confirmed in sagittae and lapilli of both larvae groups. However, sagittae were better for age determination than lapilli for larvae at earlier days. For larval G. selincuoensis older than 50 days, lapilli were the only otolith pair suitable for larvae daily age determination. This study validated the daily increment formation in Schizothoracine fish for the first time has primary implications to other fishes from this subfamily.     

Feeding of fish in Lake Glubokoe

Lake Glubokoe is inhabited by 13 species of fish. The commonest are roach, bream, perch and ruff. Comparison of seine catches for 1950 and 1984 revealed a considerable decrease in the share of perch (from 31% to 2%) and ruff (from 18.5 to less than 0.1%) in 1984. The richest food resource in the lake is crustacean plankton. In summer, it is mostly consumed by roach. Estimation of the electivity shows that, unlike perch, roach selectively consumes small crustaceans (Bosmina and Polyphemus). Poor growth rate of all common species of fish points to their food limitation. In summer the diets of common species of fish are differentiated to a considerable extent. Of 36 pairs of combinations a high food overlap was found only in 2 cases: 1) O + perch and Leucaspius delineatus, 2) yearlings and adult roach. Low diet overlap in fish during intensive feeding in summer probably reflects a feedback between the volume and intensity of food competition. The populations of bream and ruff probably compete for chironomid larvae which inhabit the sublittoral, as perch, roach and Leucaspius delineatus probably do for large littoral insects. However, intraspecific competition appears to be more important than interspecific for the roach and bream populations (the two most numerous species in the lake).     

Hydroacoustic study of spatial and temporal distribution of Gymnocypris przewalskii (Kessler, 1876) in Qinghai Lake, China

Gymnocypris przewalskii (Kessler 1876) is an endangered and state-protected rare fish species in Qinghai Lake, China. To further understand the life history and distribution of this fish, five surveys were carried out in Qinghai Lake between 2002–2006. Results of these surveys indicate that fishes were predominantly distributed about 2 m under the surface. In July, significant differences in fish density were found between surface and bottom layers (P = 0.001), and/or between middle and bottom layers (P = 0.025). Fish density was the greatest in the surface layer. In August and October, no significant differences were found between the different layers, but the bottom layer had a greater fish density. Furthermore, there were very large differences among different zones in fish distribution density. Differences in horizontal distribution were not significantly correlated to factors such as water depth and inshore distance, possibly because of very low and uniform fish density. Feeding, changes in water temperature, over-wintering and spawning appeared to influence fish distribution. Hydroacoustic estimates of G. przewalskii biomass in Qinghai Lake increased significantly between 2002 and 2006. We attribute this increase to the management measures put in place to protect this species.     

内蒙古达赉湖地区和蒙古国东方省蒙原羚的夏季食性

2008年7—8月,收集了内蒙古达赉湖地区和蒙古国东方省蒙原羚的新鲜粪便,采用粪样显微组织学分析法研究了蒙原羚的夏季食性。研究结果如下:(1)内蒙古达赉湖地区夏季植物群落在植被盖度、地上生物量、植物种数方面与蒙古国东方省差异均不显著;在内蒙古达赉湖地区和蒙古国东方省共采集常见植物18科43属63种;(2)内蒙古达赉湖地区蒙原羚共采食10科19属22种植物,蒙古国东方省蒙原羚共采食11科24属29种植物;(3)禾本科植物是内蒙古达赉湖地区和蒙古国东方省蒙原羚夏季主要食物,分别占蒙原羚食物组成的79.1%和73.2%;禾本科植物中的羊草、针茅是内蒙古达赉湖地区和蒙古国东方省蒙原羚的主要食物,分别占蒙原羚食物组成的63.6?和57.7%;(4)内蒙古达赉湖地区蒙原羚夏季食物组成生态位宽度Bj=2.0,蒙古国东方省蒙原羚夏季食物组成生态位宽度Bj=2.3;(5)内蒙古达赉湖地区与蒙古国东方省蒙原羚的食物相似性指数PS=0.7;(6)内蒙古达赉湖蒙原羚与蒙古国东方省蒙原羚主要食物秩相关性检验显著相关(P0.05),相关性系数0.6。研究表明尽管内蒙古达赉湖地区蒙原羚主要在草原围栏内活动,但与蒙古国东方省蒙原羚的夏季食性显著相似,这表明有限的活动范围没有对蒙原羚夏季食性产生显著影响。     

布哈河青海湖裸鲤鱼苗鱼卵的时空分布研究

2008年7月1日到10月7日,使用水文过河缆道及圆锥网接滤过式集苗器进行采样,对青海湖布哈河鱼类早期资源的时空分布进行了研究,以期了解青海湖裸鲤的自然繁殖状况,为其资源监测及生态保护提供基础性资料。结果表明:布哈河中鱼类早期资源种类单一,主要为青海湖裸鲤,采样期间有多次苗汛,主要苗汛出现于7月份,9月上旬仅有小规模苗汛;鱼苗平均密度3.17ind.·m^-3,最高达54ind.·m^-3;晚上鱼苗密度(22:00-22:10)与下午鱼苗密度(14:00-14:10)有显著性差异(df=98,P<0.05);青海湖裸鲤的鱼卵在上层平均密度为0.075ind.·m^-3,下层平均密度0.175ind.·m^-3,两者亦存在显著性差异(df=10,P<0.05);鱼苗的漂流运动主要集中在晚上;总体上看,鱼苗主要分布在河流上层,有近岸分布的趋势,而鱼卵则主要分布在河流下层,接近河流中央位置;鱼苗断面系数为0.43,鱼卵断面系数为2.32。     

Otolith Microstructure of Larval Gymnocypris potanini Herzenstein from the Minjiang River in China

Synopsis Otolith microstructure of about 120 Gymnocypris potanini larvae from the Minjiang River in China was examined and analyzed. Larvae had multiple primordia in most lapilli and sagittae, while had only one primordium in a few specimens. There had only one nucleus in otoliths of the larvae, except for some few specimens with 2 nuclei. The transparence of many otoliths differed from center to edge, and part of them could be divided into inner low optically dense zone (LODZ) and outer optically dense zone (ODZ). Based on increment clarity, otoliths of this species could be classified into three types, which were otolith with subtile increments, otolith with almost identified increments, and otolith with fairly clear increments characterized by high contrast. The last two types of otolith accounted for 87.07% in lapilli and 94.46% in sagittae, respectively. Increment clarity of sagitta was higher than that of lapillus. Natural checks were identified in 32.50% lapilli and 48.33% sagittae. These checks primarily located in the first to sixth increment. According to the number of increments in otoliths, the age of this batch larvae was 14 – 22 days, birth date was on June 17 – 25, and average growth rate of body length was 0.8936 ± 0.08769 mm/d.