首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 187 毫秒
1.
中华鲟人工繁殖放流现状评价   总被引:3,自引:0,他引:3  
1984-1998年,在长江葛洲坝水利枢纽下游江段,中国集团公司中华鲟研究所共捕捞663尾中华鲟亲鱼用于人工繁殖。各年的捕捞量变动在31—60尾之间。实际用于人工催产的亲鱼年利用率变动在3.1—91.7%之间。平均28.4%。催产卵的年受精率变动在0—85.0%之间,平均66.5%。年人工孵化鲟苗量变动在5—151.9万尾之间,平均54.3万尾。历年合计向长江放流初孵鲟苗4258万尾、幼鲟6.28万尾。经过多年的实践,中华鲟的人工催产,幼鲟孵化、培育和放流等方面的技术已经发展成熟。  相似文献   

2.
从长江上游一级支流龙溪河收集了1382尾厚颌鲂开展繁殖生物学研究。结果表明,厚颌鲂繁殖期为4~7月份,盛期为4~5月份,在繁殖季节可借第二性征辨别性别。繁殖群体主要由2、3龄个体组成,总性比♀∶♂=1∶1.83。厚颌鲂2龄初次性成熟(♀∶75%;♂∶94.7%),3龄个体全部成熟。最小性成熟雌性全长189.0mm,体长158.0mm,体重72.1g,成熟系数2.7%;雄性全长179.0mm,体长149.0mm,体重57.1g,成熟系数2.2%。厚颌鲂绝对怀卵量为(59587.22±59018)粒,相对怀卵量为(212.64±89.50)粒/g或(230.96±137.63)粒/mm,绝对怀卵量和相对怀卵量均在5龄大幅增长。比较繁殖力以3龄组最高,2、4、5龄组相近。集群繁殖需要18℃以上水温和其他一些生态因子刺激,亲鱼追逐约1h左右产卵。  相似文献   

3.
人工标志放流中华鲟幼鱼的降河洄游   总被引:19,自引:0,他引:19       下载免费PDF全文
1998— 2 0 0 2年期间 ,向长江放流人工繁殖中华鲟 2月龄稚鲟 (全长 7 5— 17 0cm) 17 5 2万尾 ,其中 7795 7尾用CWT进行标记 ;14月龄幼鲟 (全长 5 5 0— 98 0cm) 4 0 0尾 ,全部用外挂银牌和CWT双重标记。放流后沿长江及沿海收集中华鲟稚鲟和幼鲟样本 ,4年共回收稚鲟样本 6 4 0 0尾 ,幼鲟样本 13尾 ,检测到携带标记的稚鲟和幼鲟各 13尾。人工放流的幼鲟降海洄游的速度平均达到 2 8 6km/ 2 4h(7 1— 10 0 2km/ 2 4h) ,回捕时离放流点的距离从 346—2 4 5 9km ,平均 16 0 0km ,回捕的标志幼鲟有 4 6 2 %的个体来自海区。初步估算出 1999年和 2 0 0 0年人工放流个体在长江口幼鲟种群中的贡献率分别为 2 2 81%和 0 997%。结果表明 ,人工放流中华鲟稚鲟和幼鲟的生长、洄游及分布与自然种群没有明显差异。放流较大规格的幼鲟有利于提高成活率 ,而目前长江中华鲟种群的补充仍以自然繁殖种群为主。  相似文献   

4.
四川辖曼自然保护区硬刺高原鳅生物学研究   总被引:2,自引:0,他引:2  
对四川若尔盖辖曼自然保区220尾硬刺高原鳅的生物学进行了研究。硬刺高原鳅体长22.56~98.56mm,体重0.12~13.98g;体重与体长呈显著的幂函数关系:W=0.0095L3.2033(r=0.9956)。Fulton肥满度雌体平均为1.35,雄体平均为1.37;Clark肥满度雌体平均为1.03,雄体平均为1.05。雄性成熟个体最小体长为74.61mm,体重为5.79g。雌性成熟个体最小体长为71.06mm,体重为5.20g。平均绝对怀卵量5175粒/尾。食性主要为摇蚊幼虫,其次是藻类和维管植物。  相似文献   

5.
2013年5月-2014年6月,对青衣江下游夹江至乐山段中华沙鳅的资源现状,繁殖生物学进行了调查,并采用常规方法对73尾繁殖期野生中华沙鳅进行了观察研究,结果:73尾中华沙鳅标本,其体长在84~184mm范围,平均体长为134mm;体重在10.87~45.57g之间,平均体重为22.64g;其中31尾雌性中华沙鳅绝对怀卵量1542~7563粒,平均怀卵量为4486粒;雌雄中华沙鳅初次性成熟年龄均为2龄。  相似文献   

6.
中华鲟初次全人工繁殖的特性研究   总被引:3,自引:0,他引:3  
结合中华鲟研究所1994—1999年野生中华鲟人工繁殖亲本的生物学特性和2000—2008年野生成熟亲鱼人工繁殖的情况,对子一代中华鲟初次全人工繁殖的特性进行了研究。结果表明:虽然初次性成熟的子一代中华鲟个体均小于野生中华鲟的成熟亲本,但性腺发育良好。经人工催产,精子具有较高的质量(快速运动60s,常温存活10min),卵子也具有较高的受精率(71.4%)和孵化率(64.3%),并成功的培育出了健康的子二代鱼苗1.8万尾。人工淡水条件下子一代中华鲟的全人工催产繁殖获得了成功,证实了中华鲟可以在纯淡水中完成其生殖周期。研究结果对濒危物种中华鲟的物种延续具有重要现实意义。  相似文献   

7.
2011年8月—2015年8月在华南地区主要河流收集255尾革胡子鲶(Clarias gariepinus)样本,对其繁殖生物学特征进行研究。结果表明:革胡子鲶繁殖季节为5—8月,繁殖旺季为6—7月,卵径分布呈现明显的多峰型;成熟系数与脂肪系数和肥满度的周年变化存在相反的趋势;绝对繁殖力为2850~605720粒,均值234232±175498粒,与体长、体重和年龄呈正相关;相对繁殖力为20~445粒·g~(-1),均值165±99粒·g~(-1),随体长、体重和年龄的增加呈先增加后趋于稳定趋势;绝对繁殖力和相对繁殖力均大于常见的鲶科鱼类。繁殖群体性比为1∶1.12,符合1∶1比例;雌、雄鱼最小性成熟个体均为1龄,Ⅳ期性腺;雌鱼体长174 mm,体重119.5 g,成熟系数为8.50%;雄鱼体长205 mm,体重116.2 g,成熟系数为0.45%;繁殖群体以1和2龄鱼为主,分别占繁殖群体总数的42.28%和51.68%,以补充群体占优势;华南地区革胡子鲶野生种群具有分批产卵、相对繁殖力高、卵径小、性成熟年龄低的特征,有利于其迅速建立稳定的种群,应加强对革胡子鲶野生种群动态的监测力度,并进一步采取防控措施。  相似文献   

8.
本文对鲮鱼的食性、年龄、生长和繁殖进行了研究,并对渔业生产提出了建议。鲮鱼以浮游植物为主要食料。在水温14.6—29.4℃时食欲旺盛。当水中溶氧量0.24—0.65毫克/升时,绝大部分个体停止摄食,而溶氧量在0.99毫克/升以上时,摄食强度很大。见到的最大个体:雌鱼体长595毫米,体重4,100克,10龄;雄鱼体长580毫米,体重3,850克,9龄。鲮鱼能在大王滩水库中自然繁殖。鲮鱼人工繁殖季节以5月初至6月中旬较适宜;催产时水温以22—29℃为好,注射催产剂的效应时间一般为4.5—6小时。见到的性成熟最小个体:郁江鲮鱼雌体长273毫米,体重525克,雄体长275毫米,体重415克;池养鲮鱼雌体长247毫米,体重366克,雄体长235毫米,体重291克。根据群众经验,一般池塘中鲮鱼每亩放养1,000尾,鲮与鲢的放养比例以3∶1较好,以鲮鱼为主体的池塘则每亩放养1,500—2,000尾较好。  相似文献   

9.
抚仙金线鲃人工繁殖与鱼苗培育技术   总被引:5,自引:2,他引:3  
抚仙金线鲃(Sinocyclocheilus tingi)是抚仙湖的特有种。2009年3-4月,有4次繁殖试验取得了成功。先后试验了40尾雌鱼和20尾雄鱼,成功催产19尾雌鱼和15尾雄鱼,分别占雌雄鱼的47.5%和75.0%。获得鱼卵25 547粒,并实施干法受精。有16 810粒受精,平均受精率为65.8%。孵化出鱼苗约6 040尾,平均孵化率为23.6%。经过20日的饲养,仔鱼存活3 056尾,存活率为50.6%。抚仙金线鲃较低的催产率,可能是生殖功能紊乱所致;但也不排除是人工营造的条件离其自然环境需求尚有距离。要使抚仙金线鲃成为鱼康鱼良白鱼(Anabarilius grahami)之后又一当地特色养殖鱼种,突破其人工繁殖瓶颈,培育高品质鱼苗是必由之路。突破其人工繁殖,还可为研究抚仙金线鲃的生活史和保护该物种免于灭绝奠定良好基础。  相似文献   

10.
Pan XF  Yang JX  Chen XY  Li ZY 《动物学研究》2011,32(2):196-203
2007—2010年,对滇池金线鲃(Sinocyclocheilus grahami)进行了亲鱼培育、繁殖力和卵径(egg diameter,ED)大小的研究。滇池金线鲃的催产率、核偏位率和孵化率分别由2007年的25.2%、61.5%和30.4%到2010年的91.3%、85.2%和44.5%。四年间这3项指标均有不同程度提高,其中,催产率提高的幅度最大。提供适合滇池金线鲃营养全面的饵料可以保证亲鱼培育的最佳效果,获得高质量的鱼卵和鱼苗。滇池金线鲃绝对怀卵量与体长的关系是F=0.0004826SL3.166(R2=0.6424,P<0.05)。四年来滇池金线鲃的平均产卵量为(2118.4±899.1)粒,平均绝对怀卵量为(2402.9±881.9)粒,平均相对怀卵量为(70.4±20.8)粒。产卵量、绝对怀卵量和相对怀卵量都有随着体长增加而增加的趋势。卵的大小与胚胎存活相关,在胚胎发育的前两天,不同批次胚胎的死亡呈现一种稳定的或低的死亡率;而后5~7d不同大小的卵呈现不同的死亡率,即小的卵具有更高的死亡率;而卵径>2.0mm的胚胎死亡率趋于稳定;大的卵有更高的生存潜力,能保证仔鱼开口前继续完善身体器官的形成或发生所需要的能量。  相似文献   

11.
Inbreeding generally reduces male mating activity such that inbred males are less successful in male-male competition. Inbred males can also have smaller accessory glands, transfer less sperm and produce sperm that are less motile, less viable or have a greater frequency of abnormalities, all of which can reduce the fertilization success and fitness of inbred males relative to outbred males. However, few studies have examined how male inbreeding status affects the fitness of females with whom they mate. In this study, we examine the effect of male inbreeding status (inbreeding coefficient f = 0.25 vs. f = 0) on the fecundity, adult longevity and the fate of eggs produced by outbred females in the seed-feeding beetle, Callosobruchus maculatus. Females mated to inbred males were less likely to lay eggs. Of those that laid eggs, females mated to inbred males laid 6-12% fewer eggs. Females mated to inbred males lived on average 5.4% longer than did females mated to outbred males, but this effect disappeared when lifetime fecundity was used as a covariate in the analysis. There was no effect of male inbreeding status on the proportion of a female's eggs that developed or hatched, and no evidence that inbred males produced smaller nuptial gifts. However, ejaculates of inbred males contained 17-33% fewer sperm, on average, than did ejaculates of outbred males. Our study demonstrates that mating with inbred males has significant direct consequences for the fitness of female C. maculatus, likely mediated by effects of inbreeding status on the number of sperm in male ejaculates. Direct effects of male inbreeding status on female fitness should be more widely considered in theoretical models and empirical studies of mate choice.  相似文献   

12.
Strategic ejaculation is a behavioural strategy shown by many animals as a response to sperm competition and/or as a potential mechanism of cryptic male choice. Males invest more mating resources when the risk of sperm competition increases or they invest more in high quality females to maximize their reproductive output. We tested this hypothesis in the false garden mantid Pseudomantis albofimbriata, where females are capable of multiply mating and body condition is an indicator of potential reproductive fitness. We predicted male mantids would ejaculate strategically by allocating more sperm to high quality females. To determine if and how males alter their ejaculate in response to mate quality, we manipulated female food quantity so that females were either in good condition with many eggs (i.e. high quality) or poor condition with few eggs (i.e. low quality). Half of the females from each treatment were used in mating trials in which transferred sperm was counted before fertilisation occurred and the other half of females were used in mating trials where fertilisation occurred and ootheca mass and total eggs in the ootheca were recorded. Opposed to our predictions, the total number of sperm and the proportion of viable sperm transferred did not vary significantly between female treatments. Male reproductive success was entirely dependent on female quality/fecundity, rather than on the number of sperm transferred. These results suggest that female quality is not a major factor influencing postcopulatory male mating strategies in P. albofimbriata, and that sperm number has little effect on male reproductive success in a single mating scenario.  相似文献   

13.
Population characteristics of pallid sturgeon Scaphirhynchus albus in the lower Missouri River are relatively unknown. Therefore, data collected from the Nebraska Game and Parks Commission Pallid Sturgeon Population Assessment Program was synthesized to (i) document the population structure of pallid sturgeon by origin (hatchery‐reared or wild), gender, and reproductive readiness, (ii) document the minimum size and age‐at‐maturity by gender, and (iii) document the fecundity rates of the fish that were successfully spawned in the hatchery. During this 4‐year study (2008–2011), relative abundance for wild and hatchery‐reared pallid sturgeon collected with gill nets did not significantly change whereas relative abundance for wild fish using trot lines declined significantly. The proportion of hatchery‐reared pallid sturgeon increased annually, with the population being composed primarily of hatchery‐reared fish. The proportion of reproductively ready females to non‐reproductively ready females was 1 : 2.0, compared to male ratios at 1 : 0.9. Minimum fork length‐at‐maturity was estimated for females at 788 mm and for males at 798 mm. Minimum age‐at‐maturity for hatchery‐reared released fish was age‐9 for females and age‐7 for males. Highest relative fecundity, based on the ovosomatic index, was 10% with an overall mean of 7%. The number of eggs per ml (egg size) was not correlated with fork length (P = 0.0615) or weight (P = 0.0957). Relative condition factor (Kn) for females was significantly different by reproductive condition (P = 0.0014) and Kn for males did not differ between reproductive conditions (P = 0.2634). Detecting shifts in population characteristics are essential not only to understand population dynamics since hatchery inputs and natural perturbations continue to change the population structure but also to assess species recovery efforts to ensure long‐term species sustainability.  相似文献   

14.
FEMALES RECEIVE A LIFE-SPAN BENEFIT FROM MALE EJACULATES IN A FIELD CRICKET   总被引:7,自引:0,他引:7  
Abstract.— Mating has been found to be costly for females of some species because of toxic products that males transfer to females in their seminal fluid. Such mating costs seem paradoxical, particularly for species in which females mate more frequently than is necessary to fertilize their eggs. Indeed, some studies suggest that females may benefit from mating more frequently. The effect of male ejaculates on female life span and lifetime fecundity was experimentally tested in the variable field cricket, Gryllus lineaticeps. In field crickets, females will mate repeatedly with a given male and mate with multiple males. Females that were experimentally mated either repeatedly or multiply lived more than 32% longer than singly mated females. In addition, multiply mated females produced 98% more eggs than singly mated females. Because females received only sperm and seminal fluid from males in the experimental matings, these life‐span and fecundity benefits may result from beneficial seminal fluid products that males transfer to females during mating. Mating benefits rather than mating costs may be common in many animals, particularly in species where female mate choice has a larger effect on male reproductive success than does the outcome of sperm competition.  相似文献   

15.
The reproductive biology of the Oxleyan pygmy perch Nannoperca oxleyana is described from simultaneous studies of wild populations in north-eastern New South Wales and mature fish held in aquaria. In the wild, 50% of males and females matured at total lengths of 24·0–25·9 and 28·0–29·9 mm, respectively. The species displays sexual dichromatism during the spawning season, with males developing more intense red and brown fin and body colouration, and black pelvic fins. Captive male broodfish displayed territoriality during the breeding season, closely guarding sites within artificial, plant-like substrata in which pairs of fish spawned adhesive eggs. Protracted serial spawning of wild and captive fish occurred from September to April and May at mean water temperatures ≥16·6° C and day length ≥10·7 h. Captive broodfish spawned on an average of 57% of days during the 256 day spawning period. Gonado-somatic indices averaged 0·7% for all ripe males and 4·1–4·2% for all ripe females collected. Mean total and batch fecundities of captive females were 1323 eggs per fish and 7·8 eggs per fish per day, respectively, and relative fecundity was 587 eggs g−1 of body mass. Batch fecundity of wild females was estimated at 7·8 eggs per fish. The adaptive significance of this reproductive strategy in a harsh, variable environment is discussed.  相似文献   

16.
Individuals are expected to invest more in current reproductive effort when paired with a partner of higher than average quality. Aidablennius sphynx is an external fertilizing fish with paternal care in which females gain direct benefits from spawning with large males, but often 'make do' with small males. In this study, female reproductive responses to large and small males were investigated. When paired with large males, females spawned more eggs per unit time (i.e., at a faster rate). There was no difference in the size of the eggs spawned by females in relation to partner size. By ovipositing at a faster rate, females may have allocated more reproductive effort to large males. In addition, since small males are known to release far fewer sperm than large males, females may have reduced their spawn rate with small males as a tactic to ensure fertilization.  相似文献   

17.
A new method was developed for artificial insemination of the silkworm. Virgin females artificially inseminated by this method oviposited fertilized eggs at a rate almost similar to that of females mated with males. Using inactive sperm collected from the seminal vesicles, we confirmed the previous finding by Omura, S., 1936a, Artificial insemination of Bombyx mori, Journal of Faculty of Agriculture, Hokkaido Imperial University 38, 135-150, and Omura, S., 1938, Studies of the reproductive system of the male of Bombyx mori II, Post-testicular organs and post-testicular behaviour of the spermatozoa, Journal of Faculty of Agriculture, Hokkaido Imperial University 40, 129-170, that the sperm of B. mori requires the secretion of the glandula prostatica for activation. Sperm also could be activated by trypsin. At an optimal concentration, 0.3 &mgr;g trypsin/ml in 50% semen solution, the fertilization rate as well as the number of eggs oviposited was almost equivalent to that obtained in normally mated moths. These results may contribute not only to basic studies on fertilization and reproduction in Lepidoptera but also to the development of long-term preservation of genetic resources by using cryopreserved sperm of B. mori and other Lepidoptera insects.  相似文献   

18.
Stress reduces the quality of gametes produced by rainbow trout.   总被引:1,自引:0,他引:1  
In this study we have used the rainbow trout as a model animal to study the biological consequences of stress in terms of gamete quality and quantity. Groups of 30 mature male and female rainbow trout were subjected to repeated acute stress during the 9 mo prior to spawning. Time of ovulation, fecundity, and egg size were recorded in mature females, and sperm counts were carried out on the milt from the male fish, from both the stressed and control groups. Eggs from ovulated females were fertilized with milt from males subjected to the same treatment regime. Approximately 300 eggs from each female were fertilized with a sperm dilution of 10(-3) in diluent. Subsequent development of the fertilized eggs was then monitored. There were no differences in somatic weight or length between the two groups at the end of the experiment, but exposure of rainbow trout to repeated acute stress during reproductive development resulted in a significant delay in ovulation and reduced egg size in females, significantly lower sperm counts in males, and, perhaps most importantly, significantly lower survival rates for progeny from stressed fish compared to progeny from unstressed control fish. Hence, stress reduces the quality of gametes produced by rainbow trout.  相似文献   

19.
金沙江中下游圆口铜鱼的繁殖生物学   总被引:2,自引:0,他引:2  
根据2013—2014在皎平渡圆口铜鱼产卵场的定点亲鱼收集(n=206)和2006—2014年在金沙江中下游金安桥至巧家干流江段的流动亲鱼采集(n=70), 对圆口铜鱼的繁殖生物学进行了初步研究。定点亲鱼收集的结果显示: 圆口铜鱼雌性最小性成熟个体全长330 mm, 体质量441.0 g, 年龄4龄; 雄性最小性成熟个体全长352 mm, 体质量396.6 g, 年龄3龄; 50%个体达到性成熟的年龄和全长分别为雌性4.32龄 406 mm, 雄性4.44龄 412 mm; 繁殖群体雌雄性比为1.37﹕1, 繁殖群体中雌性年龄为4—7龄, 雄性年龄为3—7龄; 雌雄个体的性成熟系数平均值均以6龄个体最高, 分别为10.55%和3.45%; 平均卵径为0.16 cm, 卵径分布呈双峰型。定点和流动亲鱼收集的雌性性成熟个体的结果表明: 圆口铜鱼绝对繁殖力变动范围为4055—137900粒/尾, 平均值为22817粒/尾; 相对繁殖力变动范围为5—73粒/g, 平均值为20粒/g, 75.68%个体的绝对繁殖力在10000—30000粒/尾之间, 70.27%个体的相对繁殖力在15—20粒/g之间; 绝对繁殖力和相对繁殖力均随着体长和体质量的增加而增加, 其中全长、体质量与绝对繁殖力呈指数分布函数正相关, 而与相对繁殖力呈二次项函数正相关。研究结果可为长江流域圆口铜鱼资源的保护提供重要的基础数据支撑。  相似文献   

20.
Reproductive biology of blue sucker in a large Midwestern river   总被引:1,自引:0,他引:1  
Efforts to protect or rehabilitate depressed blue sucker Cycleptus elongatus populations require an understanding of life‐history characteristics and reproductive biology to provide fisheries managers with the tools required for science‐based management. The objective of this study was to examine the reproductive biology of blue sucker in the Wabash River, Indiana, during March and April 2006. A total of 105 reproductively mature blue sucker (53 males, 52 females) was collected using boat electrofishing to examine size‐at‐maturity, absolute fecundity, gonadosomatic index (GSI), relative fecundity, and estimated egg size. Size‐at‐maturity was estimated at 515 mm total length (TL) for males and 568 mm TL for females. Mean absolute fecundity of females captured during the study was 150 704 eggs per female (range, 26 829–267 471 eggs per female) and was positively related to both TL (r2 = 0.66) and wet weight (r2 = 0.77). Mean GSI was 6.4% (range, 2–9.3%) for males and 17.2% (range, 4.3–23.4%) for females. Relative fecundity ranged from 15 331 to 65 887 eggs kg?1 body weight (mean = 46 946 eggs kg?1 body weight) and was strongly correlated with GSI (r2 = 0.87). Mean estimated egg size was 278 eggs g?1 (range, 229 364 eggs g?1) and exhibited an inverse relationship to GSI (r2 = 0.42). The results of our study provide information on the reproductive biology of blue sucker which can be used to aid in the identification of potential recovery threats for depressed populations.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号