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 46 毫秒
1.
2008年4月下旬至5月上旬,在金沙江攀枝花段共采集了160尾中华沙鳅(Botia superciliaris),对其繁殖生态学进行了初步研究。结果表明,中华沙鳅的绝对怀卵量最大为10681粒,平均为6780粒;相对怀卵量最大为443粒/g,平均为269粒/g。中华沙鳅性比接近1∶1,产漂流性卵,产卵类型为一次性产出,繁殖高峰期为5~6月。为保护我国鱼类的生物多样性,应加强对中华沙鳅繁殖种群的保护。  相似文献   

2.
温涛  何斌 《淡水渔业》2012,(4):94-96
2011年5~12月,对金沙江屏山以下江段中华沙鳅(Botia superciliaris)的资源现状、繁殖特性进行了调查,并在实验室对该鱼的人工繁育进行了探索。所获中华沙鳅雄鱼(n=251)平均体长81.3 mm,平均体重8.7 g;雌鱼(n=486)平均体长109.7 mm,平均体重15.9 g。屏山调查点中华沙鳅占总渔获物(尾数)的2.68%,日均单船产量平均为0.12 kg;安边调查点中华沙鳅占总渔获物(尾数)的0.17%,日均单船产量平均为0.06 kg。雌雄性比为1.31∶1;雌、雄最小性成熟年龄均为2+龄。雌鱼的绝对怀卵量最大值为5 948粒,平均为4 455粒。中华沙鳅属一次性产卵类型,在流水中产漂流性卵;繁殖高峰期在5~6月。人工繁育时,受精卵在水温25~26℃孵化29 h仔鱼出膜,孵化率约70%,刚出膜仔鱼全长4.9~5.1 mm。半年后幼鱼的成活率为11.13%,全长约30 mm。  相似文献   

3.
赛里木湖新疆高原鳅生物学研究   总被引:12,自引:0,他引:12  
本文对赛里木湖新疆高原鳅的形态特性、生长、食性及繁殖习性等生物学进行了观察研究。经观测赛里木湖新疆高原鳅雌性体长7.8cm(6.0g),雄性体长9.0cm(8.2g)达性成熟。繁殖时间5-7月,平均绝对怀卵量20096粒/尾。食性以钩虾为主,其次是摇蚊幼虫。本文还对新疆不同水域新疆高原鳅形态特征进行了比较,并就赛里木湖水域环境对新疆高原鳅的影响进行了探讨。  相似文献   

4.
大宁河贝氏高原鳅的繁殖特性   总被引:1,自引:0,他引:1  
以长江上游巫山段支流大宁河的贝氏高原鳅(Triplophysa bleekeri)为对象,研究其繁殖特性。结果表明:贝氏高原鳅第二性征明显,雌雄易于区分。繁殖群体雌雄性比为1.09∶1,最小性成熟年龄雌雄鱼均为2龄。精巢1对,成熟系数为0.05~1.30;卵巢1个,成熟系数为1.10~48.23,雌雄的成熟系数曲线均为双峰型。雌性绝对繁殖力为1 080~4 040粒,平均2 865粒。相对生殖力F/OW为198.49~941.68粒/g,平均690.97粒/g。相对生殖力F/L为14.21~53.16粒/mm,平均41.10粒/mm。卵径分布曲线亦为双峰型,卵径0.2~1.1 mm,平均卵径0.66 mm。贝氏高原鳅具有一年繁殖两次、精巢长期具有成熟精子的特点。  相似文献   

5.
本对阿克苏河叶尔羌高原鳅的形态特征、群体结构、繁殖、食性等生物学进行了研究。叶尔羌高原鳅体长分布在3.0~15.0cm之间,体重分布在1~33g之间。W=0.039748L^263049.Fulton肥满度雌体平均为1.54,雄体平均为1.46;Clark肥满度雌体平均为1.25,雄体平均1.16。雌体成熟个体最小体长为6.6cm,体重为5.5g,平均绝对怀卵量11543粒/尾。食性以底栖动物、水生昆虫以及鱼类幼体为主。  相似文献   

6.
2009年对塔里木河干流叶尔羌高原鳅[Triyplophysa(Hedinichthys)yarkandensis(Day)]群体生物学进行研究。叶尔羌高原鳅体长、体重相关方程为:W=0.0190L2.8911;相对怀卵量平均为(1160.7±364.7)粒/g,性腺处于Ⅳ期发育阶段的雌、雄鱼平均成熟系数分别为(13....  相似文献   

7.
按常规生物学方法,对长江铜陵段紫薄鳅(Leptobotia taeniops)的形态特征、体长与体重关系、肥满度、食性、繁殖等个体生物学特征进行了初步研究。结果表明,所取样本体长范围为6.81~12.40cm,体重范围为7.00~36.24g;体长与体重呈显著的幂函数关系:W=0.0348L2.7480(r=0.9090);为偏动物食性的杂食性鱼类。以体长8.00~10.00cm组的肥满度为高,雄性的Fulton肥满度随体长的逐渐增加而降低。性成熟年龄在1+~2+龄,4~7月份产卵繁殖,卵为半漂浮性。种群性比为1:1.4,V期绝对怀卵量平均为2602粒,相对怀卵量平均为127粒/g,成熟卵的卵径达(1.47±0.10)mm。年龄分为3个组,其中2+龄个体占63.79%。  相似文献   

8.
前鳍高原鳅Triplophysa anterodorsalis Zhu Cao, 1989是一种长江上游特有鱼类,其主要分布在金沙江下游水域。2014年1-12月在金沙江一级支流黑水河下游江段逐月采集样本,对其繁殖特征进行了研究。结果显示:前鳍高原鳅的性成熟个体在1-2月以及9-12月出现,其雌、雄个体的性成熟系数平均值均在12月份达到最大值;50%个体达到性成熟的全长分别为雌性72 mm,雄性78 mm;繁殖季节雌雄性比为0.98:1;平均卵径为0.64 mm,卵径分布呈单峰型;绝对繁殖力变动范围为1428-6356粒/尾,平均值为3834粒/尾;相对繁殖力变动范围为250-938粒/g,平均值为535粒/g;全长、体质量与绝对繁殖力呈二次项函数正相关;繁殖季节的水温变动范围为9.3-20.6 ℃,平均值为14.1 ℃。研究表明:前鳍高原鳅有明显的产卵集群情况,且其为一种均衡策略者鱼类。本文能够为前鳍高原鳅资源的保护,特别是为其全人工繁殖技术的实现提供基础数据支撑。  相似文献   

9.
2004年6月至2006年4月,对柴窝堡湖新疆高原鳅生物学特性进行了研究.结果表明:柴窝堡湖新疆高原鳅体长与体重关系为W=0.017633L2.811659.群体体长以70~80 mm最多,占总样本的37.3%;体重在3~7 g的占84.6%.绝对怀卵量在649~11 280粒,平均2 654粒;卵径0.5~0.9 mm,平均为0.7 mm.卵为粘性卵,产在沿岸的石砾和植物茎上.通过观测,目前柴窝堡湖新疆高原鳅受寄生虫感染的比例较高,达65.4%.柴窝堡湖新疆高原鳅捕捞产量较大,占年总产量的6%.  相似文献   

10.
云南裂腹鱼繁殖生物学研究   总被引:5,自引:0,他引:5  
2001~2004年连续4年现场调查,采样解剖研究。云南裂腹鱼首次性成熟年龄为雌鱼3龄、雄鱼2龄;繁殖期为每年的2月中旬至4月下旬,产卵盛期是3月下旬至4月上旬(农历春分至清明时节)。怀卵量少,个体绝对怀卵量1 656~33 855粒,平均10 980粒;相对怀卵量15.53~48.2粒/g,平均24.23粒/g。雌雄性比为1∶5。  相似文献   

11.
12.
Previously, we reported 10 PEGE types of 85 tilapia Streptococcus agalactiae(GBS), which shifted from Streptococcus iniae in China, by using PEGE method. Presently, larger and more representative tilapia GBS were isolated, for the ?rst time in China, to characterize their serotypes and genetic diversities more precisely than had done before. 168 GBS strains were distributed in ?ve provinces of China, in which Guangdong, Guangxi and Hainan were the major ones, holding36.9%(62/168), 37.5%(63/168) and 19.6%(33/168), respectively. Serotypes, Ia, Ib and III, were observed in these strains and the most predominant one was Ia(95.2%), which mainly distributed in Guangdong, Guangxi and Hainan. Ia initially occurred in 2009, it shoot up to 32.1% in 2010,but decreased to 16.1% in 2011 before went up to 45.2% in 2012. Ib sporadically occurred during2007–2011, III onlyoccurred in 2012. 14 different PFGE types, including 4 new types(N, O,P and Q), were observed, in which B, D, F and G were the predominant types, holding 83.9%(141/168) of the total GBS strains. Ia corresponded to 11 PFGE types(A–H, N–P), in which type D predominated(51%). Ib represented 3 genotypes(I, J and Q) and III harbored only 2genotypes(N and F). Type N and Fsynchronously presented in Ia and III. In summary, the genetic diversity of tilapia GBS varied by serotypes and changed with geographical locations and years.Although Iastillpredominated, new rareserotypeIII alreadyoccurred in China.  相似文献   

13.
The environmental processes associated with variability in the catch rates of bigeye tuna in the Atlantic Ocean are largely unexplored. This study used generalized additive models (GAMs) fitted to Taiwanese longline fishery data from 1990 to 2009 and investigated the association between environmental variables and catch rates to identify the processes influencing bigeye tuna distribution in the Atlantic Ocean. The present findings reveal that the year (temporal factor), latitude and longitude (spatial factors), and major regular longline target species of albacore catches are significant for the standardization of bigeye tuna catch rates in the Atlantic Ocean. The standardized catch rates and distribution of bigeye tuna were found to be related to environmental and climatic variation. The model selection processes showed that the selected GAMs explained 70% of the cumulative deviance in the entire Atlantic Ocean. Regarding environmental factors, the depth of the 20 degree isotherm (D20) substantially contributed to the explained deviance; other important factors were sea surface temperature (SST) and sea surface height deviation (SSHD). The potential fishing grounds were observed with SSTs of 22–28°C, a D20 shallower than 150 m and negative SSHDs in the Atlantic Ocean. The higher predicted catch rates were increased in the positive northern tropical Atlantic and negative North Atlantic Oscillation events with a higher SST and shallow D20, suggesting that climatic oscillations affect the population abundance and distribution of bigeye tuna.  相似文献   

14.
Growth hormone (GH) and reproduction: a review   总被引:5,自引:0,他引:5  
Interaction between growth and reproduction occurs in many vertebrates and is particularly obvious at certain stages of the life cycle in fish. Endocrine interactions between the gonadotropic axis and the somatotropic axis are described, the potential role of GH being emphasised. A comparative analysis of these phenomena in mammals, amphibians and fish, suggests a specific role of GH in the physiology of puberty, gametogenesis and fertility. It also shows the original contribution made by studies on the fish model in this field of investigations.  相似文献   

15.
Protein and amino acid composition of the mantle of juvenile O ctopus vulgaris (Cuvier, 1797) during fasting for 27 days were determined. Average protein content of octopus mantle was of 711.19 ± 46.80 g kg?1 DW, and it decreased with increasing fasting days. The non‐essential amino acids content was higher (486.18 ± 11.08 g kg?1 protein) than essential amino acids (425.82 ± 9.15 g kg?1 protein) at the start of the experiment (unstarved animals). The results suggest that the amino acid profile of the mantle where the most abundant amino acids are Arg, His, Lys, Gly, Leu and Pro could indicate a prolonged fasting condition (>20 days) or poor nutrition of O . vulgaris. This study supports the idea of using mantle for metabolic needs of starved O . vulgaris suggesting that the degradation pathway of amino acids to pyruvate and tricarboxylic acid cycle intermediates was favoured contrary to the degradation pathway of ketogenic amino acids. Special considerations should be taken concerning Thr, Ile, Ser, Ala, Asx (Asp, Asn), Glx (Glu, Gln) (because of their fast intake) and Lys and His (due to their stable contents) during a prolonged period of fasting.  相似文献   

16.
In this experiment, a feeding trial was performed to determine the effects of fructooligosaccharide (FOS) on growth performance, digestive enzyme activity and immune response of Japanese sea bass, Lateolabrax japonicus juveniles (initial weight 38.3 ± 0.5 g), and the fish were examined following feeding with six levels of FOS (0, 0.5, 1, 2, 4 and 6 g/kg) for 28 days. Significant enhancement of weight gain (WG) and specific growth rate (SGR) was found in fish fed 1 g/kg FOS incorporated diets (p < .05), while the feed conversion ratio (FCR) in the 1, 2 g/kg FOS groups reduced significantly compared with the control (p < .05). Besides, the crude lipid in the 4, 6 g/kg FOS groups increased significantly compared with the control (p < .05). On the other hand, the erepsin and lipase activities significantly elevated in intestine of fish fed 2 g/kg FOS (p < .05) and the lysozyme activity in serum of fish fed 2 g/kg FOS were significantly higher than that in the control (p < .05). Moreover, the alkaline phosphatase activities in serum of fish fed 0.5, 1, 2 g/kg FOS were significantly higher than in control (p < .05). Regression analysis showed that the relationships between dietary FOS levels and either SGR, FCR, erepsin or lysozyme activities were best expressed by regression equations, and the optimal inclusion levels are 1.37, 1.80, 3.06, 3.11, 1.93 and 1.80 g/kg for SGR, FCR, erepsin, lipase, lysozyme and total superoxide dismutase activities, respectively. Overall, this study revealed that FOS incorporated diets could beneficial for L. japonicus culture in terms of increasing the growth, digestion and immune activities. Under the present experimental condition, the optimal supplementary level of FOS in the diet of L. japonicus is 1–3 g/kg.  相似文献   

17.
18.
Two gonadotropins (GtH; Qa and Qb) were purified by gel filtration and ion exchange chromatography from the pituitaries of Indian walking catfish (Clarias batrachus). The presence of GtH during purification was assessed by in vitro oocyte maturation and in vivo steroidogenic activity, and their identities were determined by elution profiles, molecular weight, biological activities and yield. The molecular weights of Qa and Qb were 37 and 42 kDa, respectively, and composed of distinct subunits (Qa: 20 and 14 kDa and Qb: 26 and 18 kDa). Polyclonal antibodies raised against Qa immunostained Qa, Qb and pituitary GtH cells. A competitive Qa‐ELISA was developed whose sensitivity was 6.25 ng mL?1 (1.25 ng well?1) with intra‐ (3.5%) and inter‐ (12.4%) assay coefficients of variation. Displacement curves parallel to the standard were obtained with plasma and pituitary extracts of catfish, Qb and carp GtHII. The assay was validated by measuring the plasma Qa levels after LHRH treatment and in relation to ovarian growth in the female catfish during different reproductive phases. Based on the results, Qa and Qb corresponded to fish LH and FSH respectively. The findings will increase the knowledge of the mechanisms controlling fish reproduction and identification of sensitive phases in fish in captivity for hormonal manipulation.  相似文献   

19.
The endemic, anadromous cyprinidChalcalburnus tarichi is the only fish species known to occur in alkaline Lake Van (Eastern Anatolia, Turkey). EightC. tarichi were maintained individually in Lake Van water (17 – 19°C; pH 9.8; 153 mEq·I–1 total alkalinity; 22 total salinity) and tank water samples analyzed for 24 h in 2 to 4 h intervals. At zero time, < 1µM ammonia was present and urea was undetectable in the tank water; at 24 h, total ammonia and urea made up 114±32 and 35±25µM, respectively. Over the experimental period, ammonia-N and urea-N excretion averaged 1041±494 and 607±169moles·kg–1 fish·h–1, respectively. The extent of urea excretion was highly variable between specimens. Uric acid excretion was not detectable.Urea was present at high concentrations in all tissues and plasma (25 – 35moles·g–1·ml–1) of freshly caughtC. tarichi; total ammonia content of the tissues was by a factor of 1.9 (liver) to 3.0 (brain) lower. High arginase activity (2.4±0.2 U·min–1·g–1) was detected in the liver ofC. tarichi but ornithine carbamoylphosphate transferase, a key enzyme of the ornithine-urea-cycle, was absent. Ureagenesis is likely through degradation of arginine and/or uricolysis. High glutamine synthetase activity (11±0.6 U·min–1·g–1) and low ammonia content in brain suggest that, like other teleosts,C. tarichi has an efficient ammonia detoxification in the brain, but in no other tissue.Nitrogenous waste excretion at alkaline pH is discussed. The ability ofC. tarichi to excrete high levels of ammonia at extremely alkaline pH is unique among teleosts studied so far. The mechanism of ammonia excretion under Lake Van conditions remains to be elucidated.  相似文献   

20.
Tetrahymena is a protozoan parasite, which infects guppy, Poecilia reticulata Peters, and causes substantial economical losses in commercial farms worldwide. Studies of guppy infected by Tetrahymena require standardized infection protocols. The LD50 for Tetrahymena infection of guppies by intraperitoneal (IP) injection was calibrated, and the level obtained was 946 parasites per fish. Guppy infection with Tetrahymena by immersion, imitating the natural route of infection via the integument, was studied under normal or stress conditions. Exposure to cold and netting (CNI) and to cold only (CI) followed by immersion exposure to 10 000 Tetrahymena per mL resulted in 22.5% and 19.2% mortality, respectively, as compared to 14.2% and 10% in groups that were netted only (NI) or non‐stressed (I). Histopathology revealed that immersion infection resulted in a systemic infection. Lysozyme levels, measured 3 weeks after infection, were significantly higher in the CNI group (288 μg per mg protein) compared with CI‐, NI‐ and I‐treated groups (94.5, 64 and 62.3 μg mg?1, respectively). There was no evident parasite immobilization activity in body homogenates, suggesting no development of acquired immunity. Re‐infection by IP injection revealed no increase in protection in any of the treatment groups, mortality range of 56.3–75%, higher than in the non‐exposed control (40.6% mortality).  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