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1.
方斑东风螺人工育苗技术   总被引:10,自引:2,他引:8  
本文报道了方斑东风螺人工育苗试验.方斑东风螺亲螺日摄食率5—8%,亲螺夜间产卵,具卵囊,每个卵囊含卵约1千粒,以卵囊柄粘附于池底,呈悬浮状态。在水温28.0—29.0℃,盐度29的条件下,受精卵孵出卵囊的时间5—7d。浮游幼虫投喂角毛藻,孵化第13d开始出现变态的稚螺。浮游期壳长日均生长67.5um。池底铺沙培育稚螺,变态15d的稚螺,壳长可达3mm。  相似文献   

2.
谢刚  刘伟光 《珠江水产》1990,(16):67-69
孵出后第11-13天的仔鳗,体长与体高之比约为11.9:1,油球0.023-0.015mm。上,下颌具齿4对,口多数时间张大,偶见有启闭,多数时间在池底,头朝下贴近底壁,尾斜朝上不停摆作找食状,游动时明显呈鳗形游动,肠内常可见有黑色的似食物 的小团块。第16-17天的仔鳗油球已基本消失,体长与体高之比约为11.3:1,吻部渐前移,第18-20天的仔鳗,体长与体高之比约为10.6:1。油球已消失,口属次端位,口经常张得很大,便很少见有主动启闭,仔鳗活存第20天,467小时。  相似文献   

3.
本文探讨了罗氏沼虾亲虾培育,人工半咸水育苗技术,结果表明:水温28.5±0.5℃时,罗氏沼虾相邻两次产卵间隔时间为30-40天,从产卵到第一期蚤状幼体孵出需14—16天,水温29.5±0.5℃时,从第一期蚤状幼体卵出到虾苗淡化需26天。水簇箱中进行罗氏沼虾育苗试验,取得了淡化虾苗产量为81尾/升和94尾/升的结果。  相似文献   

4.
孔鳐胚胎发育的初步观察   总被引:2,自引:0,他引:2  
王者茂 《水产学报》1982,6(2):153-164
孔鳐是一种营底栖定居性生活的经济软骨鱼类。产卵期在四至八月,盛期为四月下旬至六月。在整个产卵期中;一尾雌鱼平均可产22—31枚卵。雌鱼产出带有卵壳的胚胎,在水温16—25℃,pH7.70-7.88,盐度为28—30‰,水中溶氧为2.7—4ml/L的海水中,平均70天幼鱼便可由卵壳的前粘合部处,破壳而出。出壳时间最长为90天,最短为48天。刚孵出的幼鱼全长7—8厘米。  相似文献   

5.
真蛸为福建省近年来新兴的海水养殖优良种类,具有较高的营养价值、商品价值和产业化养殖前景。本文报道了福建省水产研究所2008年-2011年真蛸人工繁殖及受精卵孵化结果:127头雌亲蛸经强化培育,共有77头产卵,获卵194×10^4粒,孵出143.4×10^4头浮游幼体。雌亲蛸获产率46.2%~86.7%,卵子受精率75.6%-91.8%,受精卵孵化率77.9%~95.0%。在20.0~22.5℃水温条件下,真蛸受精卵经21~36d开始孵出,孵出后4~6d为孵出高峰,每窝卵开始孵出至孵化结束维持10—16d。  相似文献   

6.
鳗鲡属隶属于硬骨鱼纲(Osteichyes)、鳗鲡目(Anguilliformes)、鳗鲡科(Anguillidae)。鳗鲡目鱼类大多数生于海洋,但鳗鲡科鱼类大部分属降河繁殖洄游鱼类,它们在海洋中产卵繁殖,幼鳗孵化后漂游到沿岸,然后进入淡水河流中成长。鳗鲡属共有17种,广泛分布在世界各地,其中有12种是属热带和亚热带种类。一、人工繁殖鳗鲡的研究早在30年代人们就开始鳗鲡人工催熟的试验。1973年春日本北海道大学山本教授等首次获得受精卵。同年年底和次年初孵出了第一批人工繁殖的仔鳗,仔鳗存活了120小时,我…  相似文献   

7.
三亚产斑节对虾亲虾产卵量的测定   总被引:1,自引:0,他引:1  
通过对三亚产斑节对虾亲虾产卵量的测定,结果表明:该市亲虾质量好,个体大。成熟雌性亲虾的体长大多在210 ̄270mm之间,体重在150 ̄270g之间,交配率为90% ̄95%,成熟度高,催熟效果好,重复产卵周期为4 ̄6天;成熟雌性亲虾的体长大多在195 ̄235mm之间,体重在110 ̄200g之间;亲虾体长和体重成正比例关系。雌性亲虾的产卵量与个体大小成正比,产卵量多在50 ̄80万粒之间。  相似文献   

8.
文中介绍秦岭大鲵繁育基地的亲鲵人工繁殖技术。三年间连续催情32组,自然交配产卵雌鲵27尾,共获卵14000粒,并连年孵化出苗。其中,产空卵带亲鲵5尾,催繁成功率为84.4%。每年7月下旬至8月底性腺发育成熟为最佳催情期;交配产卵池要彻底清池,严控给水流量与水深;以及亲鲵繁殖与护卵行为等系列要素。  相似文献   

9.
泰山赤鳞鱼的胚胎发育和仔鱼发育   总被引:1,自引:0,他引:1  
试验结果表明:泰山赤鳞鱼产卵时间在4~5月,自然产卵水温为18~26℃,产卵于水底细沙中,分散产卵。卵呈弱粘性,金黄色,属沉性卵,平均卵径2.5 mm。在水温18~22℃条件下,胚胎从受精到孵化出膜历时66 h,经过了胚盘形成期、卵裂期、囊胚期、原肠胚期、神经胚期、器官分化期6个主要阶段。初孵仔鱼全长6.0~6.5 mm。卵黄囊前部膨大成球形,约占鱼体整个长度的1/3;后端为均匀的棒状。仔鱼孵出到消化道完全形成约经历136 h。  相似文献   

10.
锈斑(蟳)亲蟹培育试验初报   总被引:6,自引:0,他引:6       下载免费PDF全文
从市场采购或由野外采捕野生锈斑蟳的成体,采用内分泌、营养和环境条件三个方面结合起来的方法进行亲蟹培育和人工催熟:摘除亲蟹的单侧眼柄;投喂双壳类增加营养;控制水温在25℃~28℃,盐度30—32,pH值8.0~8.4,DO5mg/L以上,光照强度0~1500lx。本试验亲蟹的培育成活率达93.3%,抱卵率85.7%,孵化率83.3%。试验结果表明,甲长6.3~7.9cm的雌蟹,经过培育,性腺均可发育成熟,均可抱卵。锈斑蟳属一次性产卵类型,可多次抱卵。水体中聚缩虫等原生动物的大量繁殖直接影响锈斑蟳胚胎和幼体的正常发育和孵化,也是幼体培育成活率低的原因之一。  相似文献   

11.
为证明日本鳗鲡(Anguilla japonica)生活史最后一步一产后鳗的命运,本研究模拟产后的日本鳗鲡继续在海水中养殖,观察其存活率及繁育情况.结果表明,产后鳗在海水中停食约18 d后,体能得到恢复,部分亲鱼开始出现摄食,1个月左右全部恢复摄食,经244 d养殖,雌、雄鳗体质量增加,存活率达94.6%.随后,给产后鳗注射外源性促性腺激素(鲤鱼脑垂体匀浆CPE和人绒毛膜促性腺激素HCG)后激发其退化的性腺(卵巢和精巢)重新发育(与当年银鳗作对照).通过性腺组织切片观察产后鳗和对照鳗性腺发育成熟的全过程及其差异,发现产后鳗起初性腺发育比当年银鳗差,但经多次注射激素后,产后鳗性腺成熟与当年银鳗同步,证明产后鳗生殖细胞对激素的敏感件高.应用17α,20β-双羟孕酮和促性腺激素释放激素类似物(GnRH-A3)使催熟的产后鳗和对照鳗均产卵和排精,并孵化出仔鱼,从而有力地证明,鳗鲡产后虽体质弱,但待体能恢复后能够继续生存和繁殖.本研究旨在探讨利用产后鳗作为今后鳗鲡人工繁殖亲鳗的可行性.  相似文献   

12.
Two adult male freshwater eels, Anguilla japonica, were captured in June 2008 in the West Mariana Ridge (13°N, 142°E) in the North Pacific, but collections of females have yet to be reported. In September 2008, we successfully caught two adult female A. japonica, 55.5 and 66.2 cm in total length, in the adjacent but northern area (14°N, 143°E). Six newly hatched eel larvae (pre-leptocephali) were also collected by subsequent plankton sampling conducted near the female catch area. Female adults appeared to be in the post-spawning state, probably a considerable time after spawning, since a small number of remarkably regressed oocytes (50–250 μm in diameter) were observed in the ovaries. Capture of post-spawning female eels and newly hatched larvae near the Suruga Seamount (14°N) together with the previous collection of mature males in the southern area (13°N) corroborates that the area along the West Mariana Ridge is the spawning area of this species, but suggests that the eel spawning may occur over a wider area than previously expected.  相似文献   

13.
异齿裂腹鱼人工规模化繁殖技术研究   总被引:5,自引:1,他引:4  
张良松 《淡水渔业》2011,41(5):88-91,95
2010年4~6月,对野生异齿裂腹鱼(Schizothorax o' connori)人工规模化繁殖技术进行研究,并初步进行产后亲鱼恢复培养技术研究.对108尾雌鱼进行干法人工授精,共采卵104万多粒,孵出仔鱼62万多尾.其中45尾雌亲鱼自然成熟,共采卵46.8万多粒,平均受精率和孵化率低于人工催产雌鱼卵.人工催产83...  相似文献   

14.
Oogenesis of abalone Haliotis discus hannai was examined histologically during a single spawning season using broodstock of various maturation conditions, which were controlled by effective accumulative temperature (EAT). The quality of eggs spawned was determined in relation to oogenesis. For histological examinations, three to five females were sacrificed at 300, 600, 850, 1050, and 1150 °C days EAT, without induction of artificial spawning. Other females were successfully induced to spawn at 700 °C days EAT and were reared following spawning. Three of these females were then sacrificed every 200 °C days EAT until 1300 °C days EAT. Gonad histology showed that two oocyte cohorts matured in H. discus hannai ovaries during a single spawning season. One mature oocyte cohort could be spawned in multiple times. The second oocyte cohort started developing after the first oocyte cohort had been spawned or reabsorbed, and became fully mature 400 °C days EAT after the first cohort was depleted. For egg quality measurements, three to five females were successfully induced to spawn at 850, 1050, 1150, 1900, and 2350 °C days EAT (Experiment 1). Three females were induced to spawn twice, at 700 and 1500 °C days EAT, resulting in two batches of eggs from the same individuals (Experiment 2). Total lipid and protein content of eggs were measured and were greater in eggs from the second cohort than in eggs from the first cohort. No carbohydrates were detected in eggs and there was no difference in cytoplasm volume between the two cohorts. In hatcheries producing H. discus hannai, it is important to increase post-larval starvation tolerance by increasing the quality of eggs, to yield higher and more consistent survival. The results of this study suggest that H. discus hannai hatcheries should use eggs from the second oocyte cohort, which are of higher quality, rather than eggs from the first oocyte cohort.  相似文献   

15.
The high mortality rate of reared Japanese eel Anguilla japonica larvae is largely due to lower growth rate and the higher rate of deformed larvae. To establish an effective rearing protocol for this species, we examined the effects of water temperature and feeding regimes on their growth and notochord kyphosis. Larvae at 165 days post hatching were reared for 28 days at mean temperatures of 24, 25 and 27 °C, and were fed 4 or 6 times per day. Larval growth rate was significantly higher in larvae reared at 24–25 °C and fed 6 times per day. However, growth rate was significantly reduced at 27 °C, suggesting a shortage of metabolic energy due to an elevated cost of the higher basal metabolic rate at higher temperatures and low nutritional performance of currently used artificial diet. Notochord kyphosis was promoted by elevated water temperature, and two-way ANOVA showed that water temperature and feeding frequency had combined effects on the deformity. These findings suggest the importance of concurrently manipulating both environmental and nutritional factors to produce healthy eel larvae in captivity.  相似文献   

16.
Abstract.— The breeding frequency, fecundity, egg hatchability, larval output and viability of pond-reared, mature Macrobrachium rosenbergii females were individually followed up during 180 d. Sexually mature prawns were maintained under controlled laboratory conditions (28.7 C and 12-h light/d) in a 190-L freshwater recirculation system and fed a formulated diet. Ovarian development, moulting and spawning events were checked daily. At least six consecutive moults were recorded for each of the 18 females. The duration of the intermoult period averaged 27.5 d and was not affected by ovarian development or spawning, but intermoult periods followed by spawning had significantly lower growth rates. From a total of 126 moulting events recorded, egg laying successfully followed 76 (60.3%) of them. The number of eggs per spawn (NES) varied from 26,587 to 74,775 for females weighing 20.0 to 55.8 g. The relationship between NES and female size (W; in g) was found to be NES = 484 + 1454W ( r 2= 0.74). Results suggest that the number of viable larvae produced per egg clutch may be increased by in vitro incubation, as the losses of eggs, which usually occur under in vivo incubation, are prevented. The present study illustrates that under adequate and stable rearing conditions, M. rosenbergii females are able to spawn up to five times during 180 d, in comparison to three to five times per year as reported for wild prawn populations.  相似文献   

17.
Some anguillid spawning areas are known based on collections of small larvae, but recently for the Japanese eel Anguilla japonica, adult spawners have been caught in trawls and their eggs and preleptocephali collected. The spawning area of A. japonica is located along the western side of the West Mariana Ridge, but the natural spawning behavior of this species or that of any other anguillid species has never been observed. This study reports on the first effort to observe spawning aggregations of anguillid eels that was conducted by the R/V Yokosuka using the Shinkai 6500 submersible and a Deep-Tow camera system in the A. japonica spawning area in July 2012. The submersible was deployed mostly at 200–800 m during daytime and the Deep-Tow was deployed mostly at 130–250 m during nighttime, both in multiple oblique depth tracks along linear transects. Various fishes and invertebrates were seen in the pelagic environment during day and night, but no spawning aggregations were observed. One eel was briefly recorded by a Deep-Tow camera at 20:13 on 17 July (2 days before new moon) at a depth of 179 m. The eel was recorded for <1 s as it passed in front of the camera. Its anterior body and head shape were consistent with a male A. japonica, or possibly a Derichthys serpentinus eel, but not with other mesopelagic eels. Because the tail region of the eel was not visible, species identification was not possible.  相似文献   

18.
The migration duration of European eel ( Anguilla anguilla ) larvae (leptocephali) from the spawning areas in the Sargasso Sea to the European continental shelf remains highly controversial, with estimates varying from 6 months to more than 2 yr. We estimated the fastest migration period and the shortest distance travelled by eel larvae by simulating Lagrangian particles released in the Sargasso Sea and by simulating a range of larval behaviours (fixed-depth drift, vertical diurnal migration and active-depth selection to maximize current velocity). This enabled us to compute (i) a passive drift speed, and (ii) a hypothetic swimming speed needed for European eel larvae to cross the Atlantic in 6 months (i.e., the migration duration estimated from otolith daily growth increments). Our results show that the minimum travel time for an eel larva that is passively drifting was 10 months and 3 days. Active behaviours (vertical diurnal migration and rheotaxis) paradoxically increased the migration period. We found that for leptocephali to cross the Atlantic Ocean in 6 months, they would need to swim a minimum of 3.4 body lengths per second for 8200 km. No larvae have been observed with such swimming capabilities. These results provide evidence that leptocephali cannot cross the Atlantic in 6 months.  相似文献   

19.
Treated with combined bilateral eyestalk ablation and maintenance of water temperature at 22.5±1.5 °C, mud crab Scylla paramamosain females with mature ovaries were induced to produce eggs outside the natural spawning season in subtropical southern China. Newly extruded eggs from a crab were incubated in vitro at 10, 15, 20, 25, 27, 30, 35 °C, respectively, and the embryonic development was closely monitored. Abnormal cell division was observed at temperatures 10 and 35 °C. At 15 °C, development remained at the gastrula stage by day 32 post‐spawn, at which time the experiment was terminated. Hatching of in vitro incubated eggs occurred between 20 and 30 °C. An increase in incubation temperature from 20 to 25 °C reduced the incubation duration by 14 days, 2.6 times of that measured for a similar 5 °C increase from 25 to 30 °C. Embryonic development of S. paramamosain was divided into stage 0–10, and the duration of each stage was recorded for each incubation temperature. The information obtained allows accurate prediction of hatching time of female crabs incubated under variable temperatures. Larvae hatched from in vitro incubated eggs were reared to reach first juvenile crab stage and their dry weights were similar to those of larvae hatched naturally.  相似文献   

20.
The provision of fry and fingerlings, independent of the natural spawning season, can facilitate the implementation of innovative rearing strategies also in pike perch ( Sander lucioperca L.). As strict pharmaceutical acts or codes of conduct for organic aquaculture can constrain fish farmers in inducing spawning with hormonal applications, this study intended to develop protocols for advanced and postponed spawning just by simple photo-thermal treatments. After spending between 31 and 61 days at temperatures below 10 °C, different groups of pike perch spawners were treated with light and temperature programmes to advance spawning. Reproduction could be induced successfully 2 months before the natural spawning season when the mating pairs spent 43 or more days below 10 °C, followed by a maturation phase of 44–68 days at 15 °C and 16 h illumination per day. Advanced spawning could be documented for 32 out of 35 females (91%) that underwent photo-thermal treatments. Mean commercial fecundities up to 24% and average rates of developing eggs of 65% were observed in advanced spawning groups. Coldbanking of mature females allowed to postpone spawnings for 2 and 3 months. However, no egg development could be recorded in these treatment groups.  相似文献   

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