共查询到19条相似文献，搜索用时 156 毫秒
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聚缩虫病害是养殖对虾中常见病害之一,70年代外国专家就提出用福尔马林能有效地防治对虾聚缩虫病,国内也有许多资料介绍这方面的防治技术,但多属于药物对聚缩虫和对养殖对虾毒性方面的论述。近年来,由于水产养殖业的发展,虾塘进行综合性地开发利用,普遍混养贝类,因此如何筛选虾、贝混养塘防治聚缩虫病害的有效药物这是需进一步试验研究的新课题。我们曾选 相似文献
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XLP涂料对合浦珠母贝成活率、生长及附着生物量的影响 总被引：2，自引：0，他引：2
研究了XLP防污涂料对合浦珠母贝Pinctada fucata成活率、生长及附着生物量的影响。经XLP防污涂料处理后的贝，其附着生物量明显低于对照组；经防污涂料处理后的养殖网笼具，其附着生物量也明显低于对照组；贝和养殖网笼具同时用XLP防污涂料处理时，防生物附着的效果最好。经XLP防污涂料处理后，处理前期（30～60d）合浦珠母贝养殖成活率与对照组的成活率接近，或者略低于对照组；养殖120d后试验组成活率则高于对照组。使用XLP防污涂料处理后养殖120d，合浦珠母贝的个体大小及体重高于对照组。试验结果表明，使用XLP防污涂料能有效防御污损生物附着，有利于合浦珠母贝的养殖。 相似文献
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干露及淡水浸泡对菲律宾蛤仔稚贝生长和存活的影响 总被引：4，自引：0，他引：4
于2004年3—5月研究了干露及淡水浸泡对菲律宾蛤仔稚贝生长及存活的影响。试验结果表明,(1)同种规格稚贝耐干露和淡水浸泡能力随着温度升高而下降;相同温度下,不同规格稚贝耐干露能力随规格的增加而增大,耐淡水浸泡能力在稚贝壳长9.5mm时,随规格增大而增大,当稚贝规格9.5mm时,耐淡水浸泡能力随规格的增大而减小。(2)经干露和淡水浸泡的稚贝在开始7d内生长缓慢,生长速度远不及未经处理的稚贝,7d后各种规格的稚贝生长明显加快,达到、甚至超过未经处理稚贝的生长速度,存在补偿生长现象。 相似文献
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马氏珠母贝不同地理种群内自繁和种群间杂交子一代感染多毛类寄生病的分析 总被引：4，自引：2，他引：4
选用我国马氏珠母贝 3个地理种群 ,北海野生种群 (BW ) ,大亚湾野生种群 (DW)和三亚野生种群 (SW)作为亲本 ,通过不同地理种群内自繁产生了 3个子一代群体 (BB1 、DD1 、SS1 )和不同地理种群间杂交产生了 3个子一代群体 (BD1 、BS1 、DS1 )。比较分析 6个子一代群体感染多毛类寄生病的情况表明 ,马氏珠母贝是多毛类寄生虫的易感贝类 ,多毛类寄生虫基本上是凿贝才女虫 ;子一代的感染率在 66 7%～ 75 5 %之间 ,雌、雄贝之间的感染率无显著差异 (P >0 0 5) ,双壳同时感染多毛类寄生虫的感染率大于仅单壳(左壳或右壳)感染的感染率(P <0 0 5) ,在同一个群体内 ,感染多毛类寄生病与未感染多毛类寄生病贝的形态性状指标 (壳长、壳宽、总体重和壳重 )无显著差异 (P >0 0 5) ,说明多毛类寄生病并未影响马氏珠母贝的生长。多毛类寄生病的主要危害是导致马氏珠母贝的大量死亡。杂交子一代群体DS1 和BD1 的多毛类寄生病率与自繁群体BB1 相比 ,分别降低了 8 4%和8 8% (P <0 0 5) ,表明种群间杂交一代初步提高了马氏珠母贝抗多毛类寄生虫病的能力。 相似文献
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广东雷州流沙湾养殖企鹅珍珠贝多毛类寄生虫病的调查 总被引：1，自引：0，他引：1
对流沙湾养殖的企鹅珍珠贝(Pteria penguin)多毛类寄生虫病进行了调查。结果显示,锥形笼养殖2~4年的企鹅珍珠贝母贝多毛类寄生虫病感染率为39.13%~44.98%,开放式养殖2~4年为26.6%~35.63%,同一养殖方式各龄母贝多毛类寄生虫病感染率之间差异不显著(P>0.05);养殖时间两年时,多毛类寄生虫病的感染率与养殖方式之间存在极显著差异(P<0.01);养殖时间3年和4年时,多毛类寄生虫病的感染率与养殖方式之间存在显著差异(P<0.05)。锥形笼养殖的企鹅珍珠贝左壳较易感染多毛类寄生虫病。企鹅珍珠贝感染多毛类寄生虫病后,其生长与健康贝相比,无显著差异(P>0.05)。 相似文献
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浅谈围塘养殖的病害防治策略 总被引：1，自引：0，他引：1
<正> 我国的海水围塘养殖业起步较晚,早期养殖的主要对象是中国对虾,以后逐渐有贝、鱼、蟹的养殖。1993年开始,全国暴发对虾病害,各地都开展了病害防治研究,效果不理想,对虾养殖陷入低谷。尽管由于全国范围内普遍推广了虾塘综合利用,综合效益有很大提高,但是暴发性病害不仅在养殖虾类而且在鱼、贝、蟹类中都有出现,严重影响我国海水围塘养殖业。 本文对海水围塘养殖的病害防治研究进行归纳总结,提出围塘养殖病害防治的二大策略,以期对围塘养殖病害防治技术研究有 相似文献
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在东莞市黄唇鱼自然保护区救护基地黄唇鱼亲鱼培育“渡咸”过程中,发生了寄生东方鱼虱病害。在通过肉眼观察、镜检确诊病害种类后,开展了敌百虫、硫酸铜+硫酸亚铁等药物处理和淡水浸泡等小水体治疗试验,在此基础上又进行了养殖池塘治疗试验。结果表明,敌百虫是治疗池塘养殖黄唇鱼寄生东方鱼虱行之有效的药物。 相似文献
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广东省水产养殖病害防治中心 《海洋与渔业》2008,(2):48-48
一、1月病害发生情况
根据广东各测报点本月水产养殖病害监测数据分析，1月份监测种类病害的发病范围、发病率与死亡率总体相对比较低，对虾、罗非鱼和鳜鱼的病害仍比较严重。主要病害有鱼类烂鳃病、细菌性败血症、肠炎病、水霉病、纤毛虫病、指环虫病、车轮虫病、小瓜虫病、罗氏沼虾白浊病、对虾白斑病、红体病等。发病种类5种以上的养殖品种有草鱼、鳗鱼、鳜鱼、鳖、南美白对虾共4种。在局部地区养殖鳜鱼车轮虫病发病率达到70％、指环虫病死亡率达到84％， 相似文献
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ABSTRACT: For pearl production, pearl oyster seeds from foreign pearl oysters as well as hybrids between native and such foreign pearl oysters are produced in Japanese hatcheries. However, it is very difficult to identify these pearl oysters and hybrids based on morphological measurements. Thus, a molecular identification method for distinguishing Atlantic pearl oysters Pinctada imbricata from the Indian-Pacific pearl oyster group including P. martensii and P. fucata , was developed. The polymerase chain reaction (PCR) products of the partial intergenic spacer (IGS) of nuclear ribosomal RNA (rRNA) genes exhibited length polymorphism between P. imbricata (590 bp) and the other two species (427 bp). The restriction fragment length polymorphism analysis of the PCR products (PCR-RFLP) cleaved with Mse I observed in the IGS of nuclear rRNA genes also gave different profiles between P. imbricata and the other two species. The difference in PCR-RFLP using Alu I was also detected in the mitochondrial 16S rRNA gene regions between P. imbricata and the other two species. Thus, the method developed enables the distinction of P. imbricata from P. martensii and P. fucata . 相似文献
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Ziman Wang Linda Adzigbli Zhe Zheng Chuangye Yang Yuewen Deng 《Aquaculture Research》2020,51(10):3925-3934
Round nucleated pearls are produced through a surgical operation, where a round nucleus and a mantle tissue ‘saibo’ from donor oyster are inserted into the gonad of the host oyster. The epithelial cells in the mantle tissue proliferate around the nucleus, and thus, the pearl sac is formed. Pearl sac secrets nacre and forms a pearl. The quality and economic value of pearls are assessed by pearl features such as colour, brightness, lustre and shape. Among all these features, colour has been reported as an important economic indicator and has been widely studied by researchers. Generally, pearl colour is affected by the donor oyster which is determined genetically and biological pigments (melanin and carotenoid). Organic matrices, metal ions and other factors have also been reported to influence the colour of a cultured pearl. Recently, multi‐omics methods have been used to study the colour formation of pearl, and some key genes and signal pathways related to the colour formation of pearls have been identified. Nevertheless, the specific mechanism of pearl formation needs further research. The review combines both fresh and sea water pearls focusing on Hyriopsis cumingii and pearl oysters to provide a general overview and understanding for pearl colour formation. 相似文献
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Vasant Kripa Kolliyil S. Mohamed Tharammal S. Velayudhan 《Journal of the World Aquaculture Society》2012,43(4):514-525
Biofouling on the periostracum of pearl oysters and on the cages has been considered as a stress factor causing mortality of the farmed stock, reducing growth rates and also affecting pearl quality. In farming experiments using the pearl oyster, Pinctada fucata, at Kollam Bay (India), biofouling was found to be a problem. This study was conducted to understand the effect of fouling on the mortality of pearl oysters kept in suspended culture, to identify the main foulers, the seasonal variation in biofouling and species successions in the community with reference to abiotic factors. The average monthly mortality rate (MR) was estimated as 0.117 ± 0.002 and the monthly variations were significantly different (P < 0.01). The total fouling (0.163 ± 0.002 g/g oyster) and biofouling weights (0.166 ± 0.007 g/g oyster) were high in December when the fouling community was composed of several species and dominated by the ascidian, Didemnum sp. December was also the period when the MRs peaked indicating that this organism was the main cause of mortality in pearl farms in Kollam Bay. A clear seasonality in the fouling community (25 species belonging to nine phyla) has been observed in the present study. On the basis of this study, monthly cleaning of oysters is advocated except during December, January, and March when the cleaning should be fortnightly. 相似文献
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Phenotypic indicators for cultured pearl size improvement in the black‐lipped pearl oyster (Pinctada margaritifera): towards selection for the recipient growth performance 
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下载免费PDF全文 The black‐lipped pearl oyster, Pinctada margaritifera, is the most important farmed species in French Polynesia and the basis of the most valuable export industry. Mass production of black pearls relies on a surgical operation requiring tissue from a donor pearl oyster to be grafted, together with a nucleus made of shell, into the gonad of a recipient oyster. Improving pearl size through family selection remains one of the main challenges for future aquaculture development. This study analyses the relative contribution of donor and recipient oysters to pearl size. To this end, hatchery‐produced donor oysters of two batches, large and small (based on shell height), were used to supply grafts for recipients, which were then monitored individually for their growth performance by recording shell height, width, and thickness, and total live weight (flesh + shells) every 6 months (four biometric measurement times) over 20 months of culture. Pearls issued from the two batches of donors showed no significant differences in nacre weight or thickness. In contrast, recipient oyster shell height and total weight were increasingly positively correlated with these pearl size parameters over the culture period, becoming significant at 8 months post‐grafting. Potential therefore exists to use shell height and oyster weight as phenotypic indicators for selective breeding of recipient oysters with high growth performance to increase pearl size in P. margaritifera. 相似文献
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Hot water immersion lowers survival,shell growth rate and lysosomal membrane stability of oysters Crassostrea virginica (Gmelin) 下载免费PDF全文
下载免费PDF全文 This study compares the effect of two anti‐fouling treatments, hot water immersion (15 s at 60°C) and air drying (72 h) on the physiological status of the Eastern oyster Crassostrea virginica. The negative impact of hot water immersion was greater than that of air drying, but varied depending on the initial size of the oysters (40 vs. 60 mm shell height) and the time of the year (June vs. August). Groups treated with hot water exhibited a higher proportion of haemocytes with destabilized lysosomal membranes (HDLM; 47.5 ± 3.1%) than those exposed to air drying (37.5 ± 2.9%). This suggests that the oyster immunocompetency may be lowered by hot water immersion. Overall, the large oysters had lower HDLM values (32.9 ± 3.5%) than the small individuals in June (45.7 ± 2.8%) but similar values in August (46.6 ± 3.5%). Small oysters subjected to hot water immersion in June exhibited a 50% reduction in shell growth and a 50% mortality rate after one month. Our results indicate that air drying is more suitable than hot water immersion as an anti‐fouling treatment for <45 mm oysters. 相似文献
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1. Foveaux Strait, a narrow seaway that is exposed to heavy wave action and strong tidal currents, has been the subject of an oyster fishery for over 130 years. Before the oyster fishery commenced the seafloor was extensively covered by epifaunal reefs that were tidally‐oriented, linear aggregations of patch reefs. 2. Patch reefs are formed by the bryozoan Cinctipora elegans cemented by encrusting bryozoa, ascidians, sponges, and polychaetes. The molluscan epifauna is dominated by the oyster, Tiostrea chilensis and bysally attached bivalves. Mortality of oysters is probably lower and recruitment and growth may be higher within the reef habitat. 3. Fishers found commercial densities of oysters occurred only on epifaunal reefs. Fishers exploited local groups of reefs. These groups form the patchily distributed oyster beds characteristic of this fishery. 4. Dredging for oysters progressively modified reefs until oysters were the only epifauna remaining. Dredges caught oysters more efficiently after the catch bag no longer became saturated with other epifauna. This heightened efficiency allowed fishers to rapidly reduce oyster density to commercial extinction. Oyster density has not rebuilt on oyster beds abandoned by fishers. 5. The rate of modification of epifaunal reefs was slower during the early years of the fishery but has accelerated, especially over the last 37 years. Frequency of disturbance increased as the numbers of vessels fishing grew and fishers developed speedier dredging methods. Intensity of disturbance also increased as heavier dredges were introduced and allowed focused fishing of reefs. 6. Oysters became reduced to low densities in the eastern and central areas that fishers then abandoned. The commercially exploited area subsequently expanded to the limits of Foveaux Strait. 7. With accelerated modification of oyster habitat, disease mortality has become more important. 8. Attempting to rebuild the fishery by oyster enhancement may be more successful conjoined with habitat restoration. Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
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Masatomi Hosoi Seiya Sugihara Kouta Kato Shoshi Mizuta Yoshihiro Yokoyama 《Fisheries Science》2014,80(4):819-825
The effects of immersion salinity on the food properties [water content, salinity, and free amino acid (FAA) content] of shucked oysters were analyzed. Results of a laboratory immersion experiment suggested that the molluscous parts (other than the adductor muscle) swelled in lower salinity and shrank in higher salinity. Higher FAA content was observed in oysters immersed in higher-salinity water. In the adductor muscle, water content increased and FAA content decreased markedly following immersion, regardless of salinity, probably because of intake of immersion fluid and leakage of FAAs across the cut end of the adductor muscle. Immersion salinity ranged from 0.17 to 1.54 % in shucked oyster products on the retail market. Tissue salinity was strongly correlated with immersion salinity (r = 0.904), and tissue water content was correlated negatively with immersion salinity (r = ?0.668). In addition, total FAA and taurine content of oysters were correlated with immersion salinity (r = 0.629 and 0.865, respectively). These results clearly indicate that immersion salinity is an important factor affecting the food components of shucked oysters. 相似文献
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Age‐dependence of cultured pearl grade and colour in the black‐lipped pearl oyster Pinctada margaritifera 下载免费PDF全文
下载免费PDF全文 Pinctada margaritifera is an economically important marine bivalve species for cultured pearl production in French Polynesian aquaculture. In order to evaluate the influence of donor oyster age on pearl quality traits, experiments were conducted over 6 years using both grafts and surgreffe operations. At harvest, six pearl quality traits were recorded and compared: surface defects, lustre, grade, darkness level and visual colour. Analysing the quality traits of pearls harvested in the initial graft process and those of pearls obtained from surgreffe experiments allowed a comparison of the influence of pearl sac cells originating from the initial mantle graft, which aged together with their recipient oysters. The results demonstrated a significant decrease between these successive grafts in lustre, grade (A‐B‐C), darkness level, and green colour – traits that are of major importance in the pearl market. The duplicated graft experiment allowed the comparison of donor oyster families at 2 and 5 years old, where a mantle graft was inserted into recipient oysters aged 2.5 years. The results showed the same tendencies to a lesser extent, with (i) an improved pearl grade, predominantly through a most important rate of 0 surface defect category, and (ii) a green/grey ratio in favour of the younger donor. A comparison between the graft‐surgreffe and the duplicated graft experiments also highlighted: (i) the indirect role played by the younger recipient oysters, which must be optimized for optimal pearl quality realization, and (ii) the complex interplay between the donor and recipient oysters. 相似文献