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1.
李鲁晶 《海洋渔业》1996,18(4):150-152,149
附着最佳投放时间的确定是虾夷扇贝育苗生产中的关键技术。本文通过一个生产性试验,即在虾夷扇贝育苗中眼点幼虫出现后的第2、6、8天,分三个批次分别投放附着基。依据不同批次的附着基上幼虫的附着量、变态与发育生长情况,得出虾夷扇贝育苗中附着基的最佳投放时间为眼点幼虫出现后的第3 ̄4天,并对其机理及虾夷扇贝育苗的生产工艺的改进进行了讨论。  相似文献   

2.
陈远 《水产科学》1998,17(2):18-21
本文报告了采用聚乙烯网衣作为虾夷扇贝,海湾扇贝稚贝附着基的附着效果,对变态幼虫至稚贝斯的生长和成活稚贝及附着期中间育成率等进行了对比试验,结果表明,采用网衣队基变态幼虫附着速度比棕帘慢,变态幼虫至稚贝的附着率及其日生长平均值分别为:采用网衣附着基,虾夷扇贝稚贝附着率为51.9%,平均日生长为18.28μm,棕帘为54%,19.0μm,而海湾扇贝网衣为49.98%,21.4μm,棕帘为59%,21.  相似文献   

3.
虾夷扇贝面盘幼虫细菌性疾病的病原研究   总被引:1,自引:0,他引:1  
从发生下沉死亡的虾夷扇贝面盘幼虫中分离到3株细菌X1,X2,X3,经过人工感染试验证实,3株细菌均对虾夷扇贝面盘幼虫具有致病性。应用PCR技术扩增16S rRNA基因的部分序列,并对其序列进行测定,同源性分析结果表明,这3株细菌分别与交替单胞菌属、冰居壶属和假交替单胞菌属的菌株具有较高的相似性,相似性均超过98%。10种抗生素的药敏试验结果表明,3株细菌对菌必治均敏感。  相似文献   

4.
本文报告了采用聚乙烯网衣作为虾夷扇贝、海湾扇贝稚贝附着基的附着效果。对变态幼虫至稚贝期的生长和成活稚贝及附着期中间育成率等进行了对比试验。结果表明,采用网衣附着基变态幼虫附着速度比棕帘慢,变态幼虫至稚贝的附着率及其日生长平均值分别为:采用网衣附着基,虾夷扇贝稚贝附着率为51.9%,平均日生长为18.28μm,棕帘为54%,19.0μm。而海湾扇贝网衣为49.98%,21.4μm,棕帘为59%,21.0μm。稚贝中间育成率及单位水体出苗量分别为:虾夷扇贝网衣为20.8%、69.17万枚/m3,棕帘为16.43%、58.57万枚/m3,海湾扇贝网衣为18.99%、88.3万枚/m3,棕帘为18.34%、60.0万枚/m3。  相似文献   

5.
<正>幼虫下沉是海湾扇贝人工育苗过程中的常见问题,严重的会导致育苗失败,笔者根据多年从事扇贝育苗科研与生产实践,在分析幼虫下沉原因的基础上,提出相应技术措施。1幼虫下沉原因分析在整个幼虫培育期间,都可能出现幼虫下沉现象,其中以壳顶幼虫前期和刚投附着基附着变态期间最为常见。由于幼虫抵抗力弱,培育密度一般较  相似文献   

6.
2014年10月,利用PCR-DGGE技术分析了标准化养殖池塘中仿刺参(Apostichopus japonicus)肠含物及附着基和底泥中细菌的菌群结构及其相关性。结果显示,仿刺参肠含物、附着基、底泥中细菌多样性较高,分别平均获得30.00±1.00、15.33±1.70、21.67±2.62条带,肠含物中细菌种类数显著高于附着基和底泥。聚类分析和戴斯系数表明,不同池塘的仿刺参肠含物样本单独聚为一支,相似性达到0.785,附着基和底泥样品聚为一支,平均相似性达到0.532。不同样品DGGE图谱中20条优势条带的切割、克隆、测序,共获得了20条细菌序列,表明肠含物细菌种类以聚球藻属(Synechococcus sp.)、脱硫杆菌属(Desulfobacterium)、脱硫叠球菌属(Desulfosarcina sp.)、极地杆菌属(Polaribacter)、Algibacter sp.为主,附着基中主要以Robiginitalea sp.和Silicibacter sp.为主,底泥样品中主要以假单胞菌属(Proteobacterium)、噬胞菌属(Cytophaga)、Desulfosarcina sp.为主,肠含物中细菌特有种类的分离与鉴定为仿刺参养殖潜在益生菌的开发提供基础数据。  相似文献   

7.
2014年10月,利用 PCR-DGGE 技术分析了标准化养殖池塘中仿刺参(Apostichopus japonicus)肠含物及附着基和底泥中细菌的菌群结构及其相关性。结果显示,仿刺参肠含物、附着基、底泥中细菌多样性较高,分别平均获得30.00±1.00、15.33±1.70、21.67±2.62条带,肠含物中细菌种类数显著高于附着基和底泥。聚类分析和戴斯系数表明,不同池塘的仿刺参肠含物样本单独聚为一支,相似性达到0.785,附着基和底泥样品聚为一支,平均相似性达到0.532。不同样品 DGGE 图谱中20条优势条带的切割、克隆、测序,共获得了20条细菌序列,表明肠含物细菌种类以聚球藻属(Synechococcus sp.)、脱硫杆菌属(Desulfobacterium)、脱硫叠球菌属(Desulfosarcina sp.)、极地杆菌属(Polaribacter)、Algibacter sp.为主,附着基中主要以 Robiginitalea sp.和 Silicibacter sp.为主,底泥样品中主要以假单胞菌属(Proteobacterium)、噬胞菌属(Cytophaga)、Desulfosarcina sp.为主,肠含物中细菌特有种类的分离与鉴定为仿刺参养殖潜在益生菌的开发提供基础数据。  相似文献   

8.
本文报告了采用不同规格的棕绳帘和聚乙烯网片作为墨西哥湾湾扇贝和华贵栉孔扇贝稚贝附着基的附着效果.对变态幼虫至稚贝期的生长和成活稚贝及附着期中间育成率等进行了对比试验.结果表明,采用棕帘附着基幼虫变态附着速度比聚乙烯网片快,变态幼虫至稚贝的附着率及其日生长平均值分别为:采用孔径0.5cm聚乙烯网片附着基,墨西哥湾扇贝稚贝附着率为57.1%,平均日生长为39.2um,孔径1.5cm聚乙烯网片为56.1%,39.0um;直径4mm棕绳帘附着率为59.6%,平均日生长为39.7um,采用直径6mm棕绳帘为63.1%,40.9um;而华贵栉孔扇贝采用孔径0.5cm聚乙烯网片附着基为58.4%,37.95um,采用孔径1.5cm聚乙烯网片为57.5%,36.95um;采用直径4mm棕绳帘为60.8%,38.3um,采用直径6mm棕绳帘为63.0%,39.23um.稚贝中间育成率及单位水体出苗量分别为:墨西哥湾扇贝采用孔径0.5cm聚乙烯网片附着基为26.2%、50.12万枚/m3,采用孔径1.5cm聚乙烯网片为25.4%、46.02万枚/m3;采用直径4mm棕绳帘为18.56%、37.18万枚/m3,采用直径6mm棕绳帘20.7%、45.17万枚/m3.华贵栉孔扇贝聚乙烯网片分别为24.63%、46.91万枚/m3,25.12%、48.8万枚/m3;棕绳帘分别为17.66%、35.64万枚/m3,19.25%、40.34万枚/m3.  相似文献   

9.
本试验采用聚乙烯网片与棕帘作为海湾扇贝稚贝附着基,就变态幼虫到稚贝期的生长和成活率及中间育成率进行了对比研究。结果表明,变态幼虫在棕帘上的附着速度比网片快。但稚贝的中间育成率及单位水体出苗量网片分別比棕帘高1.07%和16.2万枚/m~3。因而,网片作附着基效果优于棕帘。  相似文献   

10.
黄海北部大连沿岸虾夷扇贝天然苗采集技术研究   总被引:5,自引:0,他引:5  
在调查了2005、2006年黄海北部大连海域虾夷扇贝的繁殖期、浮游幼虫的时空分布的基础上,对虾夷扇贝海区天然采苗进行了研究。结果表明,2005、2006年该区域的獐子岛海域、大长山岛海域、广鹿岛海域养殖的虾夷扇贝的繁殖期在4月初至5月上旬,盛期在4月15~25日。4月上旬至6月中旬,在此区域均可发现大量的虾夷扇贝浮游面盘幼虫,不同区域浮游幼虫密度变化很大。5月底至6月初是面盘幼虫集中的附着变态时期,在海区投放附着袋可进行虾夷扇贝天然苗的采集。从各海区虾夷扇贝浮游幼虫的拖网调查和采苗结果看,在虾夷扇贝主要养殖区獐子岛、大长山岛海域和广鹿岛海域,浮游幼虫在浮游的初始阶段能够形成较高的密度,但在附着阶段密度极低,不能采集到大量苗种,但在远离虾夷扇贝养殖区的大李家湾和凌水湾,浮游幼虫的出现比养殖区晚,在幼虫附着期能达到较高密度。能够采集到大量天然苗种。2005年在凌水湾的采苗数量达526±131个/袋(壳长0.6~1 mm),2006年在大李家湾的采苗数量达673±200个/袋(壳长0.6~1mm)。  相似文献   

11.
本文对中国对虾糠虾幼体的一种病原菌———非01群霍乱弧菌作了研究报道。这种病的症状是病虾运动能力差、趋光性弱、镜检发现肠道肿胀。从垂死病虾中分离到5株细菌,经感染健康糠虾幼体得到与病虾相同症状。5株细菌的47项形态及生理生化特性与霍乱弧菌相同,但不被01群霍乱弧菌多价血清凝集。血清学分型结果均为不同的VBO血清型VBO5,14,26,47,56。用DNA霍乱CT基因探针菌落原位杂交及小鼠肠结扎法测肠毒素,表明菌株有强毒力。分离菌株对小鼠的LD50为158×108个/只。  相似文献   

12.
硅烷化表面海洋细菌对厚壳贻贝稚贝附着的影响   总被引:3,自引:3,他引:0  
为探讨厚壳贻贝稚贝对自然微生物膜中海洋细菌的附着行为反应,本论文研究了厚壳贻贝(Mytilus coruscus)稚贝附着与硅烷基化附着基表面、微生物膜密度以及细菌种属系统发育之间的相互关系。研究表明所测海洋细菌均能显著促进厚壳贻贝稚贝的附着;其中Staphylococcus sp. 1和Cobetia sp. 1表现出较低诱导活性,且这两株细菌形成的微生物膜密度与稚贝附着率之间无显著相关性;其他7株海洋细菌均表现出中等程度诱导活性,且所形成的微生物膜密度与稚贝附着率之间呈显著相关性。系统发育分析表明所测海洋细菌对厚壳贻贝稚贝附着的诱导活性与细菌种属无关。因而,硅烷基化表面的海洋附着细菌对厚壳贻贝附着有着显著性促进作用,本研究将为后续开展厚壳贻贝稚贝附着机制奠定了基础。  相似文献   

13.
Two bacterial strains, 4:44 and PB52, isolated from turbot(Scophthalmus maximus L.) were used during a first feedingexperiment with turbot larvae. Bacteria were either added directly tothe water on the day of hatching of the larvae (day 0), orbioencapsulated in rotifers (Brachionus plicatilis) distributedon day 2 after hatching. The two bacterial strains were found to bepresent in the water of the rearing tanks throughout the experiment. Theaddition of bacteria influenced the species-composition of themicroflora associated with intensively produced rotifers added to thetanks, and resulted in colonization of the gut of the larvae by theadded bacterial strains. The strain 4:44 showed a peak on day 9 afterhatching, and reached a mean(sem) of 2.5(1.4) × 104bacteria per larva, when added in a mixture with PB52, and 0.4(0.1)× 104 bacteria per larva, when added alone. The strainPB52, on day 12 after hatching, reached 5.2(1.5) × 104bacteria per larva when added in a mixture with strain 4:44, and12.5(0.7) × 104 bacteria per larva, when added alone.The added bacteria colonized the gut turbot larvae, whereas thebacterial land, the survival and growth of the larvae were in most casesnot influenced in a negative way by the addition of bacteria.  相似文献   

14.
ABSTRACT:     The settlement of larval top shell Turbo  ( Batillus )  cornutus in response to seven macroalgal and three benthic diatom species was examined in the laboratory. The percentages of larval settlement differed significantly among algal species, and were significantly higher on two red algal species ( Marginisporum crassissima , an articulated coralline alga, and Gelidium elegans , an agarophyte) than on the green algae, brown algae and benthic diatoms tested. Marginisporum crassissima induced larval settlement most strongly throughout the experiments. The percentage of larval settlement on a crustose coralline alga (unidentified species), which is known as a suitable substratum for abalone larvae, was much lower than on M. crassissima and G. elegans , which have morphologically complex growth forms . The percentage of settled individuals on ethanol-killed M. crassissima was much lower than on intact M. crassissima . The results indicate that physical structure is unlikely to be the main inducer of settlement; therefore, settlement of top shell larvae seems to be strongly induced by chemicals from the two red algal species. The specific distribution of juvenile top shell in the field may be at least partly determined by the strong induction of larval settlement by articulated coralline and gelidiacean algae.  相似文献   

15.
Egg capsules of Concholepas concholepas were analysed microbiologically, showing the presence of bacteria inside the capsules. The bacteria were isolated and identified, and their probiotic potential on early larvae of C. concholepas was evaluated. From 32 capsules that were examined, 45 bacterial strains were isolated, of which 67% belonged to the genus Bacillus. Survival bioassays were carried out with all the isolated bacterial strains on C. concholepas larvae. It was found that 71% of the bacteria had positive effects on larval survival. This research determined that bacteria of the genera Bacillus and Vibrio present in the capsules have probiotic potential. The bacteria that led to the greatest larval survival were Bacillus pumilus, which may be used in the cultivation of C. concholepas, because one of the limiting factors for the cultivation of this species is larval survival; thus, we propose that the probiotic strains identified in this study will be used during the cultivation of C. concholepas to enhance the chances of larval survival.  相似文献   

16.
A bacteriological study was carried out at a scallop (Pecten maximus) hatchery near Bergen, western Norway following a severe increase in mortality rates during the larval stages of the scallops. No larvae survived to settling, except for those in groups treated prophylactically with chloramphenicol. In order to identify pathogenic strains of bacteria, we performed a challenge test on 10- to 16-day-old larvae using isolated bacterial strains from the hatchery. Infection with six of these strains produced mortalities that were not statistically different from that resulting from infection with the known pathogen Vibrio pectenicida. However, about 5% of the strains tested in the challenge experiment produced higher motility rates than found in the unchallenged control group, indicating a possible probiotic effect. On the basis of 16S rDNA analysis on these strains, the phylogenetic tree indicated two groups of apparent pathogens: (1) one strain, LT13, grouped together with Alteromonas/Pseudoalteromonas; (2) a cluster of strains grouped together with Vibrio splendidus (LT06, LT21, LT73, PMV18 and PMV19). Strain LT13 was isolated from cultures of the microalga Chaetoceros calcitrans used for feed, while the other strains were isolated from larval cultures. Transmission electron microscopy showed intracellular bacteria that resembled bacteria in the groups Chlamydiaceae and Rickettsiaceae.  相似文献   

17.
为探究脂多糖(LPS)对海洋细菌生物被膜形成、海洋贝类幼虫变态所产生的作用,本研究使用不同浓度的LPS直接刺激厚壳贻贝幼虫,观察其对幼虫附着变态的直接作用;同时在海假交替单胞菌形成生物被膜的过程中添加不同浓度的LPS,通过分析生物被膜生物学特性的变化,及变化后的生物被膜对厚壳贻贝幼虫附着变态的影响。研究结果显示,3种浓度的LPS均可直接诱导厚壳贻贝幼虫的变态;10 mg/L浓度LPS处理后的生物被膜其细菌密度、膜厚明显降低(p<0.05),胞外产物中多糖(如可乐酸)、脂类显著增加(p<0.05),同时其对幼虫变态的诱导作用也显著提高(p<0.05),因此推测,在厚壳贻贝幼虫的附着变态过程中,LPS具有直接诱导作用;除此之外,脂多糖还可以通过调控生物被膜胞外物质,特别是可乐酸的生成,从而间接影响厚壳贻贝幼虫的附着变态。  相似文献   

18.
中湿度表面的海洋细菌对厚壳贻贝稚贝附着的影响   总被引:3,自引:3,他引:0  
为研究自然微生物膜中海洋细菌对厚壳贻贝稚贝附着的影响,通过海洋贝类生物学、分子微生物生态学等手段调查附着基表面湿度、微生物膜的密度以及细菌种属系统发育与厚壳贻贝(Mytilus coruscus)稚贝附着关系。结果表明,所有测试海洋细菌形成微生物膜的最终密度随初始密度的增加而增加。所测海洋细菌均能不同程度地诱导厚壳贻贝稚贝的附着,其中Cobetia sp.3形成的微生物膜显示出最高诱导活性,其诱导的稚贝附着率为(70%±3%);Nautella sp.2、Pseudoalteromonas sp.9、Pseudoalteromonas sp.10、Bacillus sp.5和Pseudoalteromonas sp.11等5株细菌表现中等程度的诱导活性,其诱导的附着率范围为51%~60%。所有测试菌株所形成的微生物膜密度与稚贝附着均呈显著相关,尤其是Pseudoalteromonas sp.9和Cobetia sp.3诱导活性与附着率相关性极强,其相关性系数分别为0.774 1和0.723 3。系统发育分析结果表明,微生物膜密度和厚壳贻贝稚贝的附着率显著相关,然而海洋细菌诱导活性与细菌种属无关。因而,中湿度表面的海洋附着细菌对厚壳贻贝的附着有着明显的促进作用,本研究为后续开展厚壳贻贝稚贝的附着机制提供了理论依据。  相似文献   

19.
The aetiological agents of the abdominal swelling affecting farmed larvae of gilt-head seabream, Sparus aurata L., were studied. Four Vibrio strains were isolated from larvae of S. aurata affected by this disease, and all strains reproduced the disease in healthy larvae under controlled infection experiments, producing a significant increase of the mortality rates compared to the control (non-inoculated larvae). Several enzymatic properties, which can act as .virulence factors, were demonstrated both in the extracellular products (ECPs) and In live cells of the strains tested. Histopathological examinations of the infected fish larvae revealed important changes of the anterior intestine and liver characterized by a marked hyperthrophy of the intestinal epithelium and hepatocytes, and by a separation of the mucosal and submucosal layers in the digestive tube. These histological alterations were associated with the constant presence of cocobacillar bacteria in the anterior intestine and in the liver. However, the precise pathogenic mechanisms of the strains tested have not been completely elucidated yet.  相似文献   

20.
The large (70,000 tonnes) mussel aquaculture industry for the endemic New Zealand green-lipped mussel, Perna canaliculus Gmelin, currently relies almost entirely (80%) on wild caught seed that is often harvested attached to great quantities of floating algae. Natural vagaries in catches of wild mussel seed frequently result in shortages of mussel seed that, at times, have severely affected commercial aquaculture production. Both field and laboratory experiments were used to establish that chemical cues derived from algae significantly increase settlement of mussel larvae on artificial substrates. This is the first time an algal chemical cue has been implicated in the settlement behavior of P. canaliculus larvae. These results have potential commercial implications for improving mussel seed supply through inducing higher or more reliable levels of mussel settlement for aquaculture seed collection.  相似文献   

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