共查询到20条相似文献，搜索用时 250 毫秒
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大黄鱼是我市主要海水养殖鱼类，随着海水网箱养殖的快速发展，因对养殖品种缺乏有效选育，大黄鱼在养殖中存在生长缓慢、个体小型化、性早熟和养殖病害频发、抗逆性差等问题，影响和制约着养殖业健康持续发展。工程鱼如四倍体鱼作为鱼类选育技术研究的一个方向，四倍体鱼对于三倍体鱼的生产具有重要现实意义。因三倍体鱼具有不育或低育性可被应用于大规格商品鱼培育，同时，三倍体鱼具有良好的生存力、较好的肉质和食物转换系数等优势，而受到国内外水产科学工作者广泛重视。亲鱼培育及人工授精技术是工程鱼人工繁育的技术基础。为开展大黄… 相似文献
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中华乌塘鳢的苗种生产技术 总被引：1，自引：0，他引：1
中华鸡塘鳢（BostrichthyssinsisLacepede）是虾虎鱼科塘鳍属的广盐性暖水小型鱼类，其肉嫩味美、营养丰富，是国内外市场畅销的的食用鱼类。近几年来，我国东南沿海已有不少群众进行养殖并获得了较好的经济效益，但目前养殖所需苗种仍以天然采捕为主，由于天然苗种大小不均，数量少，供不应求，严重制约了中华乌塘醒人工养殖的产业化进程，而入工苗种大小整齐，批量大，对促进人工养殖业发展有着重要意义。一、人工孵化1．亲鱼的选择亲鱼来源有两个途径：一是从自然海区中捕获，二是从养殖池塘中收集，在生产中以地养亲鱼为主。亲鱼要求体… 相似文献
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中华乌塘鳢的苗种生产 总被引：2，自引：0，他引：2
中华乌塘鳢（AsstrichthysSinensis，Lacepede）是虎鱼科的广盐性暖水小型鱼类，肉嫩味美，营养丰富，是当今国内外市场畅销的高档食用鱼类。近几年来，我国东南沿海已有不少群众进行养殖并获得了较好的经济效益，但目前养殖所需苗种仍以天然采捕为主，由于天然苗种大小不匀，数量少，供不应求，严重制约了中华乌塘鳢养殖的产业化进程，而人工苗种大小整齐，批量大，对促进人工养殖业发展有着重要意义。一、人工育苗中华乌塘的的人工育苗是指鱼体长2～3cm前的生产过程。1．亲鱼的选择亲鱼来源有两个途径：一是从天然海区中捕获，二是从养… 相似文献
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斑鳢（Ｏｐｈｉｃｅｐｈａｌｕｓｍａｃｕｌａｔｕｓ）俗称草鲡、生鱼，是一种淡水名优鱼类，其肉质细嫩、味道鲜美，深受消费者喜爱。斑鳢的生产过去主要以天然捕捞为主，随着捕捞强度的增大，野生资源逐渐减少，因此人工育苗及养殖将成为斑鳢生产的主要方式。本研究的目的是通过亲鱼培育、人工催产、鱼卵孵化、鱼种培育摸索一套实用的斑鳢养殖技术，为今后斑鳢的规模化养殖奠定基础。一、人工繁育１．亲鱼来源２０００年从闽江流域收集体质健壮、２～３龄、体重７００ｇ～１３００ｇ的斑鳢作亲鱼。２．亲鱼培育培育亲鱼所使用的水泥池，放… 相似文献
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目前，海水和咸淡水鱼类养殖，主要仍然依靠捕捞野生种苗放养，这已成为制约生产发展的因素之一。倘能以人工种苗替代野生苗，那么，河口性的鱼类养殖，必将获得新的进展。本文将着重于讨论海产鱼类的人工诱导排卵和仔鱼培育研究问题。 相似文献
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Many species of ornamental fish, includingboth egg-layers and livebearers, exhibit a marked sexualdimorphism due to the more pigmented bodies and larger finsusually observed in males. This results in male fish commandingup to four times the price of females. Because of this pricediscrepancy, the culture of monosex (all-male) stocks ofornamental fish could be of a significant economic advantage.This paper outlines the current sex reversal technology alreadydeveloped for several fish species important for aquaculture andexamines its potential applicability to ornamental fish culture.The methods to obtain all-male stocks include direct androgentreatment and the production of YY males. The direct approach iseasy to implement and straightforward. However, in somelivebearers such as the guppy, treatment of newly born fry iscomplicated because they already have sexually differentiatinggonads and the masculinization may be temporary. In this regard,the paper stresses the importance of correctly timing treatmentin relation to gonadal development to achieve permanentmasculinization 相似文献
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Zhangjie Chu Youxian Wu Shiyuan Gong Guobin Zhang Lei Zhang Yongchao Yuan Hanwen Yuan 《Journal of the World Aquaculture Society》2011,42(1):96-104
The rice field eel, Monopterus albus (Zuiew), is an important aquaculture fish in many Asian countries. Productivity, however, is limited by low fecundity as a result of sex reversal of female juveniles of this fish. This study was conducted to investigate the effects of estradiol valerate on the sex reversal process of this fish by determining sex changes of initial 2‐yr‐old female eels (26.5 ± 2.6 cm, 21.9 ± 2.1 g) treated with three concentrations of estradiol valerate: 0 mg/kg (Control, Group A), 10 mg/kg (Group B), and 50 mg/kg (Group C). In Group A, sex reversal took place with significantly higher percentage of sex change: about 45% of female eels to intersexes and males. Only about 22% of female eels changed to intersexes and males in Group B, but no sex reversal occurred in Group C during the experimental period. The result also indicated that the gonadal development and the concentrations of serum estradiol (E2) and testosterone (T) varied significantly with different concentrations of dietary estradiol valerate. Serum T significantly reduced but serum E2 significantly increased in Group C compared to the control Group A. The results demonstrated that estradiol valerate affected the secretion of sex steroid hormones in rice field eels and thus inhibited the sex reversal process at a low concentration (10 mg/kg) or stopped the sex reversal process at a high concentration (50 mg/kg) of estradiol valerate. These results suggest that a higher yield of mature female eels could be achieved by treatments with estradiol valerate, thus enhancing the fecundity of this rice field eel. 相似文献
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黑龙江银鲫的性别控制和无性生殖系的研究 总被引：1，自引：0，他引：1
用方正银鲫()×镜鲤()所产生的全雌性后代的一部份幼鱼,投以95％酒精作性诱导剂的配制饲料,使幼鱼性转化为生理雄鱼。转化率在84％以上。此法开始处理的时间是在孵化后16—17天,处理的持续时间为30—40天。3年来,从性转化的生理雄鱼与方正银鲫雌鱼获得了无性生殖系一代,然后再从此一代获得了无性生殖系二代,以此建立了方正银鲫纯系。根据后代形态学指标、染色体数和红血球体积等确定,后代与亲本完全相似,并由此确定方正银鲫的性别决定机制,雌性为XX型,雄性为XY型。 相似文献
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半滑舌鳎养殖群体中自然性逆转伪雄鱼的发现 总被引：2，自引：1，他引：1
利用雌性特异标记遗传性别鉴定技术,对71尾4龄半滑舌鳎的生理和遗传性别进行鉴定,结果显示32尾生理型雌鱼均能扩增出205bp的雌性特异条带;39尾生理型雄鱼,仅一尾鱼体重显著高于其他雄鱼并扩增出了雌性特异条带,因此这尾鱼遗传上为雌性,是一尾伪雄鱼。对养殖的600尾半滑舌鳎生理雄鱼大规模检测发现,养殖群体自然性逆转伪雄鱼比例为1.66%。对正常雌、雄鱼和1龄自然性逆转伪雄鱼的性腺组织学观察显示,与正常雄鱼相比,伪雄鱼性腺中也有大量的精母细胞,但数量比正常雄鱼的要略少;且未在伪雄鱼的性腺组织中观察到卵母细胞,说明半滑舌鳎性逆转发生在性腺分化期。半滑舌鳎自然性逆转现象的发现有助于解释当前半滑舌鳎养殖群体中雄性率偏高的现象,为半滑舌鳎全雌苗种生产提供了一条新的技术途径,并丰富了鱼类性别分化理论。 相似文献
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The phenomenon of incidental sex reversal was observed in experiments originally designed to determine the importance of feeding duration and feed quality in the optimization of masculinization and feminization treatments of Oreochromis niloticus (L.) fry by oral application of hormones. Four separate experiments were conducted: (1) masculinization and (2) feminization using three feeding durations and (3) masculinization and (4) feminization using three alternative feed mixtures. Masculinization experiments incorporating 17 α-methyltestosterone (MT) into the feed at 40 mg kg?1 were applied to putative monosex male progeny whilst feminization treatments were applied to putative all female fry using diethylstilboestrol (DES) at 1000 mg kg?1. Treatments were applied outdoors in small cages suspended in 900-l circular concrete tanks with a flow through rate of 1-l min?1. Replicate cages for all treatments and the controls in each experiment were reared together in the same tank. Only the first experiment produced significant differences in sex ratio, with the control treatment producing a slightly lower proportion of males than the three MT treatments at different durations. The most significant finding was that in all experiments the sex ratio of the control differed significantly from expectations and in all but experiment 1, did not differ from those of the treated fish in which sex reversal had clearly been effected. It appears likely that incidental sex reversal occurred in the control fish as a result of the accumulation of active metabolites from the treated fish and/or leachates from uneaten food given to fish in the same water body. The results are discussed in the context of improving the efficiency and safety of hormonal sex reversal treatments. 相似文献
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为探究黄鳝( Monopterus albus )Caspase-3在性腺性逆转发育过程中的功能和作用,实验扩增黄鳝 caspase-3 的部分序列,检测了其在不同发育时期性腺中mRNA表达水平、蛋白相对含量以及表达位置。通过PCR扩增获得黄鳝 caspase-3 基因cDNA序列,推导的氨基酸序列对比发现,黄鳝 caspase-3 与大黄鱼( Larimichthys crocea )和鳜( Siniperca chuatsi )亲缘关系最近。实时定量PCR ( qRT-PCR)结果显示, caspase-3 mRNA在黄鳝各发育时期性腺中均有表达,在卵黄生成期性腺中表达量最高,并伴随性腺向雄性发育表达量呈下降的趋势;而其蛋白相对含量在性腺性逆转过程中呈现逐渐上升的趋势,间性晚期最高。免疫组织化学染色结果显示,Caspase-3蛋白阳性信号定位于卵黄生成期卵母细胞细胞质、皮质小泡期卵母细胞的细胞核和颗粒细胞,以及各个发育时期性腺中初级生长期卵母细胞的细胞质和细胞核。综上,Caspase-3与黄鳝性逆转过程关系密切,推测其可能参与了性逆转过程中卵母细胞的凋亡过程。 相似文献
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YASUHIRO FUJIOKA 《Fisheries Science》2002,68(4):889-893
ABSTRACT: Functional sex reversal of all-female nigorobuna Carassius carassius grandoculis to phenotypic males was examined by immersion exposure of fry to 17-methyltestosterone (17-MT) and controlled water temperature during early development. Fry were reared in water containing different concentrations of 17-MT at 24 and 30°C for 80 days starting 20 days after hatching. Although the fish exposed to 0.1 and 1.0 μg/L 17-MT at 24°C were all male, treatment with 10.0 μg/L 17-MT resulted in 43% females. Twenty-two percent males appeared in the control treatment at 30°C but the control at 24°C was entirely female. The proportion of males in treatments exposed to 0.01– 1.0 μg/L 17-MT at 30°C was slightly lower than in the respective treatments at 24°C. These results indicate that the phenotypic expression of sex in nigorobuna is thermolabile and that sex determination is under the control of genetic factors and temperature. Also, control of temperature during early development has been shown to be important for the production of all-female offspring for use as breeding stock for pond culture of fish suitable for preparation as 'funazushi'. 相似文献
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Masculinization of the Native Bay Snook,Petenia splendida,Using Oral Administration of the Synthetic Steroid 17α‐methyltestosterone 
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下载免费PDF全文 María de J. Contreras‐García Wilfrido M. Contreras‐Sánchez Alejandro Mcdonal‐Vera Ulises Hernández‐Vidal 《Journal of the World Aquaculture Society》2018,49(5):889-896
The possibility of inducing sex reversal in bay snook, Petenia splendida, was evaluated to generate a protocol aimed at producing single‐sex populations (100% males) and improving farming conditions for this species. This popular staple food is a cichlid fish native to Central America, with aquaculture potential. We evaluated oral administration of the synthetic steroid 17α‐methyltestosterone (MT) to determine optimal dosage (30, 45, and 60 mg/kg of food) and days of feeding (30, 45, and 60) to attain efficient masculinization. The statistical analysis indicates a highly significant effect of both factors as well as for the interaction (P < 0.01). We registered significant differences in growth at the end of the experiment; fish fed with 60 mg of MT for 60 d reached the largest size, while fish fed with no MT were smaller. No significant differences were observed for survival (P > 0.05), ranging from 55.7 to 75.3% in the treatments. We recommend the use of 60 mg/kg of MT for 30 d for achieving successful sex reversal. This study provides valuable information supporting the inclusion of new species in aquaculture, reducing time and costs associated with sex reversal previously proposed for the species. 相似文献
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Hanwen Yuan Shiyuan Gong Zhangjie Chu Guobin Zhang Yongchao Yuan Wenjie Gong Jianlin Yan 《Aquaculture Research》2011,42(12):1752-1763
We investigated the effects of low dietary protein in isocaloric diets on sex reversal of Monopterus albus by evaluating the oestradiol (E2) and testosterone (T) concentrations, gonadosomatic index (GSI), sex ratio and gonad structure at the histological level. Fish (9.50 ± 1.50 g average initial weight; n=3 per group) were fed with five practical diets containing 100, 150, 200, 250 or 400 g kg?1 crude protein to apparent satiation for 15 months. Serum E2 and T concentrations were determined by radioimmunoassays. E2 concentrations and GSI significantly increased while T concentrations decreased as the dietary protein level was raised. Fish fed 400 g kg?1 of dietary protein had significantly higher E2 concentrations and GSI than those fed with lower dietary protein levels. The T concentrations of fish fed 100 g kg?1 of dietary protein was significantly higher than that of fish fed higher dietary protein levels. The shift of sex ratio towards more male and intersex fish was observed with decreasing dietary protein levels. Therefore, low dietary protein level may promote sex change from female to male in M. albus. This study provides important information for successful reproductive management and may be exploited for aquaculture of this species. 相似文献
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Norhidayat Kamaruzzaman Nguyen Hong Nguyen A. Hamzah & Raul W. Ponzoni 《Aquaculture Research》2009,40(6):720-728
The growth performance of three experimental groups consisting of mixed sex fish (control), hormone-treated fish and progeny of YY male tilapia, all originated from the genetically improved farmed tilapia (GIFT) strain was evaluated. Masculinization of sexually undifferentiated fry was achieved by providing a supplement of 5 mg of 17-α-methyltestosterone per kg of feed over a period of 21 days (after sac absorption). Both mixed sex and progeny of YY male groups were fed a standard commercial ration. Mixed sex fish did not deviate significantly ( P >0.05) from the 1:1 male to female ratio. Percentages of male averaged 75% in hormone-treated fish and 95% in YY male group over the sampling periods and at final harvest. The effect of sex on weight and length was statistically significant ( P <0.001). The model used to analyse weight and length included experimental group and sex in each culture period as the fixed effects, and replicate cages as the random effect. Over the culture period of 141 days, there were no statistical differences ( P >0.05) in body weight and length between mixed sex, hormonally treated and progeny of YY males. There were also no significant differences in level of variability in harvest weight between three groups of fish when the data were classified into five categories (=<100, 100 to <150, 150 to <200, 200 to <250 and ≥250 g). It is concluded that monosex culture of all male tilapia would be of no advantage over mixed sex culture for the GIFT strain under conditions of cages suspended in earthen ponds. 相似文献