墨西哥湾扇贝选育系早期发育与生长

在水温28~29℃、盐度24~25条件下,研究墨西哥湾扇贝(Argopecten irradians concentricus)选育系的早期发育及幼虫和稚贝的生长。受精卵经50 min发育至卵裂,经22~24 h发育至D形幼虫,经11 d发育至眼点幼虫并出现足,进入附着变态阶段。选育系的胚胎发育时间和浮游幼虫前期壳长、壳高与对照系比较差异不显著(P0.05);浮游幼虫后期及至附着变态阶段,选育系与对照系的壳长和壳高差异显著(P0.05)。选育系的附着变态率和存活率与对照系比较均差异显著(P0.05),且优势明显。本研究表明,墨西哥湾扇贝浮游幼虫发育前期缓慢,幼虫后期、稚贝期生长迅速;壳长和壳高的生长速度不同步,幼虫前期壳长生长快于壳高,后期壳高生长快于壳长,并于第28~30天时壳高超过壳长。墨西哥湾扇贝选育系在幼虫和稚贝阶段生长速度明显快于对照系,具有明显的生长优势及生长潜力。     

自溶面包酵母在马氏珠母贝育苗中的饵料效果

在实验车间内利用120L的塑料箱作为实验容器,采用自溶面包酵母(Saccharomyces cerevisiae)作为单细胞藻的辅助饵料,研究其在马氏珠母贝(Pinctada martensii Dunker)育苗中的饵料效果,以期解决该贝育苗过程饵料供应不稳定、易培饵料品种小球藻(Chlorella sp.)利用率低的问题。研究结果表明:(1)在温度(30.0±0.5)℃、NaCl质量分数3%、pH6.5～7.0的自溶条件下,用经过18h自溶的酵母投喂D形幼虫,其平均日壳长增长率显著高于其他自溶时间酵母投喂组效果,单独投喂非自溶酵母时D形幼虫不能存活;(2)D形幼虫期单投自溶酵母,幼虫成活率与金藻组没有显著差异(P>0.05),生长速度比金藻组提高8%(P<0.05),说明自溶酵母可以完全替代湛江等鞭金藻(Isochrysis zhanjiangensis Hu﹠Liu),但在壳顶幼虫期和稚贝期单投自溶酵母不能使幼虫和稚贝正常发育和存活;(3)壳顶幼虫期及眼点幼虫至稚贝期投喂"自溶酵母 小球藻(Chlorella sp.)"或"自溶酵母 扁藻[Platymonas subcordiformis(Wille)]",其生长速度及存活率或稚贝育成率均显著高于单投扁藻或小球藻(P<0.05),单投小球藻的饵料效果最差;(4)自溶酵母与小球藻混投对眼点幼虫至稚贝培育效果较单独投喂影响显著,可显著(P<0.05)提高稚贝的育成率、生长速度和耐干露能力。研究表明,使用自溶酵母可以优化马氏珠母贝健康苗种规模繁育中的饵料供应工艺及提高易培饵料品种小球藻的利用价值,从而提高该贝育苗效果。     

合浦珠母贝matrilin-1基因的克隆和表达分析

以合浦珠母贝(Pinctada fucata)转录组中的matrilin-1基因片段为基础,开展了matrilin-1的c DNA全长(Pfmatrilin-1)克隆和定量表达分析。Pfmatrilin-1基因c DNA全长2 036 bp,开放阅读框(open reading frame,ORF)1 194 bp,编码397个氨基酸,包括1个信号肽序列和2个血管性血友病因子A(von Willebrand factor A,VWA)样结构域。系统进化分析显示无脊椎动物的matrilins与脊椎动物的matrilins进化关系较远。荧光定量PCR表达分析结果显示,Pfmatrilin-1 mRNA在合浦珠母贝各个组织中均有表达,其中在血液中表达量最高(P0.05);Pfmatrilin-1从担轮幼虫期至变态期均有表达,眼点期表达量最高(P0.05),而贝类幼虫发育到眼点期就会开始附着,眼点期幼虫原壳生长停滞,次生壳形成,因此推测其可能与次生壳的形成有关。这些结果表明Pfmatrilin-1在合浦珠母贝生物矿化中发挥重要作用。     

马氏珠母贝简化式育苗技术

进行了面包酵母、小球藻、扁藻、金藻在马氏珠母贝幼虫不同发育阶段的饵料效果试验,以及不同投饵量在不换水育苗方式中的育苗效果试验。结果表明:在马氏珠母贝人工育苗中D型幼虫期使用面包酵母、壳顶幼虫期使用小球藻,并通过控制投饵量,在不换水的情况下可成功地幼虫培育至变态附着,并进一步培育成商品规格的稚贝,幼虫的附着变态率可达6.5%。     

长肋日月贝个体发生观察及人工育苗初步试验

首次报道了长肋日月贝( Amusium pleuronectes )的诱导产卵及幼虫、稚贝培育.用阴干-流水刺激法,成功诱导亲贝产卵、排精.对胚胎和幼虫发生进行了观察.水温23.0～25.0℃,经诱导产卵的受精卵20 h可发育至D形幼虫.水温22.0～24.0℃时,D形幼虫经11 d培育到眼点幼虫期.投放附着基后,眼点幼虫在10 d内附着完毕.水温18.0～24.0℃时,稚贝经30 d培育平均壳长达(2.0±0.18)mm.此试验共培育壳长(2.93±1.15)mm稚贝49.6万粒.     

马氏珠母贝高产育苗技术

马氏珠母贝是我国培育海水珍珠的主要贝类,主要用于生产规格6~8毫米的有核珍珠,其培育的珍珠被称为"南珠"。近年来,不少育苗场在马氏珠母贝育苗过程中出现浮游幼虫死亡率高、变态率低、后期贝苗"掉板"等现象,导致育苗产量低、失败率高等问题,严重影响了生产效益。     

聚乙烯网片与棕帘作为扇贝附着基的对比研究

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。     

脉红螺附着变态与食性转换的研究

为实现脉红螺苗种的规模化生产,本实验通过对脉红螺幼虫培育、采苗、稚螺培育等方面的系统研究,探索了脉红螺苗种繁育过程中幼虫附着变态率低和饵料转换难的问题。结果显示:脉红螺浮游幼虫前期(0~12 d)生长较快,壳高平均日增长21.8μm;中期(13~18 d)生长较慢,壳高平均日增长3μm;后期(19~30 d)生长加快,壳高平均日增长46.8μm。用取自沉淀池中的新鲜海水对脉红螺浮游幼虫进行附着变态诱导,诱导第1天脉红螺浮游幼虫开始出现附着变态,第4天时,附着变态活动基本结束,附着变态率为40%。为变态后的稚螺投喂刚附着的长牡蛎和魁蚶稚贝,第1~8天,稚螺壳高平均日增长65.6μm;第9天开始,稚螺生长速度加快;第9~12天,稚螺壳高平均日增长136.4μm;第13~16天,稚螺壳高平均日增长307.3μm;第17~20天,稚螺壳高平均日增长445.8μm。研究表明,用取自沉淀池中的新鲜海水诱导脉红螺浮游幼虫的附着变态效果好,刚附着的长牡蛎稚贝和魁蚶稚贝可以作为脉红螺稚螺培育阶段的适宜饵料。     

马氏珠母贝混养紫海胆对污损生物防除效果的研究

利用我国南方紫海胆(Anthocidaris crassispina)与大亚湾马氏珠母贝(Pinctada martensi)进行不同比例混养,探讨了紫海胆对马氏珠母贝贝体和养殖网笼污损生物的防除效果,以及紫海胆和马氏珠母贝的生长状况。试验设混养组(PA3、PA6、PA9)和对照组(P),即在养殖马氏珠母贝30只/层的基础上,分别混养紫海胆3、6、9、0个/层;另设紫海胆单养组(A3、A6、A9),养殖密度分别为3、6、9个/层。试验结果显示：各混养组及P组间马氏珠母贝的存活率无显著差异(P>0.05),混养组紫海胆的存活率均接近100%,组间无显著差异(P>0.05);PA6、PA9组马氏珠母贝的特定生长率大于P组(P<0.05),而PA3组与P组之间差异不显著(P>0.05);就马氏珠母贝的壳长日平均增长率而言,PA3、PA9组与P组间无显著差异(P>0.05),但PA6组显著大于P组和PA3组(P<0.05);PA6、PA9组马氏珠母贝的肥满度显著大于P组(P<0.05),PA3组与P组间无显著差异(P>0.05);混养与单养各组之...     

青蛤工厂化育苗技术

青蛤(Cylinasinensis)俗称黑蛤、蛤蜊等,是我国沿海常见底栖贝类,栖息在沿海滩涂泥滩地带。为了推广青蛤育苗技术,笔者把几年来的育苗经验写出来供大家参考。一、育苗池的选择青蛤工厂化育苗过程中,幼体发育经过担轮幼虫、面盘幼虫、匍匐幼虫期,然后发育变态成稚贝而进入附着期     

栉孔扇贝（♀）×虾夷扇贝（♂）杂交子代胚后发育过程中遗传构成变化研究

采用RAPD和GISH技术对栉孔扇贝（♀）和虾夷扇贝（♂）杂交子代胚后发育4个重要时期（担轮幼虫期、D形幼虫期、壳顶幼虫期和眼点幼虫期）的遗传构成进行了检测。在RAPD检测中,50条随机引物在亲贝中共扩增出35条栉孔扇贝的特异条带和28条虾夷扇贝特异条带,其中栉孔扇贝特异条带在杂交子代4个时期出现的条数分别为：担轮幼虫期21条、D形幼虫期19条、壳顶幼虫期23条和眼点幼虫期23条;而虾夷扇贝特异条带在杂交子代4个时期出现的条数分别为：17、16、1和1。GISH结果表明,杂交扇贝在担轮幼虫期和D形幼虫期均继承了来自父母本遗传物质,而在壳顶幼虫期和眼点幼虫期未检测到来自父本的遗传物质。结果表明,杂交子代遗传结构在进入壳顶幼虫期时发生重大改变,大部分父本遗传物质从杂交贝基因组中丧失。     

Observations on artificial fertilization of eggs and the embryonic and larval development of milkfish,Chanos chanos (Forskal)

Hydrated eggs obtained from a female milkfish, Chanos chanos, were artificially fertilized with the milt collected from a male injected with acetone-dried pituitaries of salmon. The fertilized eggs (1.1–1.25 mm in diameter) developed normally in seawater in basins and petri dishes at a salinity of 30–34‰, and successfully hatched in 25–28.5 hours at a temperature of 26.4–29.9°C. The yolk was completely absorbed in about 2.5 days and during this period many postlarvae died. A few larvae were reared up to 5 days but all died on the 6th day. Attempts were made to feed the postlarvae with freshly hatched trochophore larvae of oysters obtained from eggs artificially fertilized in the laboratory.     

钝缀锦蛤繁殖周期和胚胎发育

2013年8月至2014年7月,采用组织学和实验生态学方法对钝缀锦蛤(Tapes conspersus)的性腺发育、生殖周期、肥满度、胚胎和幼虫发育进行了研究。结果显示,钝缀锦蛤性腺发育以1年为1个周期,性腺发育过程可分为增殖期、生长期、成熟期、排放期和休止期5个时期;繁殖期在每年10月至翌年3月,繁殖盛期为3月、10月和11月(水温20.3~24.6℃),分批产卵。8月肥满度最高,为33.43%;4月最低,为18.31%。钝缀锦蛤卵径为70~80μm;在水温24~26℃、盐度28~32条件下,受精卵经16 h左右发育为D形幼虫;初孵D形幼虫大小为90~110μm,浮游幼虫经7~8 d培育进入附着变态期,此时壳长为210~230μm,再经4~5 d发育变态为稚贝。本研究为钝缀锦蛤的人工繁育及种质资源保护和利用提供了基础资料。     

Investigation on redox status and gene expression related to larval cryopreservation in the Pacific oyster Crassostrea gigas

This study evaluated the effects of larval cryopreservation on redox status of post-thaw trochophore larvae and on gene expression in post-thaw trochophore larvae, D-larvae, umbo larvae, eyed larvae and spat, with the aim to understand the effects of cryodamage in the Pacific oyster Crassostrea gigas. The results showed that total antioxidant capacity was significantly higher in the cryopreserved larvae than in the control group (P?<?0.05), with no significant difference in the production of reactive oxygen species between these two groups (P?>?0.05). The expressions of FADD, Bax1, Baxlike, Bcl2, CASP7 and CAT were significantly downregulated in post-thaw trochophore larvae, whereas the expression of the SOD gene was significantly upregulated. However, the expressions of all of these genes did not significantly differ at later developmental stages. In the cryopreserved group, the expressions of GPX and ATG6 were downregulated in trochophore larvae and upregulated in D-larvae, while there were no signficant changes in the expressions of BI-1, Caspase 3 and ATG8 at all developmental stages investigated. Taken together, these results suggest that the larval cryopreservation technique developed for the Pacific oyster may compromise the survival of post-thaw trochophore larvae by modifying the redox status and gene expression patterns, but that they have limited effects, if any effect at all, after the umbo stage, indicating that the umbo stage should be used for assessing post-thaw larval performance in this species.

     

青蛤土池规模化高产育苗技术

2007-2011年,在34口面积共为100．17 hm2的土池中将阴干的青蛤挂于竹筏上进行流水刺激,催产63次,获得受精卵8150．55-108粒, D形幼虫1970．74×108只,孵化率为24．18%;幼虫正常发育变态为稚贝423．85-108粒,变态率达21．51%;培育到壳长0．50 cm的苗,收获377．02-108粒,育成率达88．95%;平均产量达3．76-108粒/hm2,达到规模化生产要求。     

Cryopreservation of trochophore larvae from the hard clam Mercenaria mercenaria: Evaluation of the cryoprotectant toxicity,cooling rate and thawing temperature

Aquaculture of hard clams Mercenaria mercenaria is a $65 million industry along the east coast and Gulf of Mexico coast in the United States. The goal of this study was to develop a preliminary protocol to cryopreserve trochophore larvae of hard clams. The objectives were to evaluate the: 1) toxicity of cryoprotectants, including dimethyl sulfoxide (DMSO), propylene glycol, ethylene glycol and glycerol, at 5, 10, 15 and 20% for exposure time of 1, 15, 30, 45, 60 and 75 min; 2) effects of cooling rates (5, 10, 20 and 30°C/min for the first trial; and 1, 3 and 5°C/min for second trial from 4 to ?80°C), thawing temperature (30, 40 and 50°C) and their interactions on post‐thaw viability. A basic protocol was concluded as: 15‐hr trochophore larvae mixed with DMSO or propylene glycol (5, 10%), equilibrated for 15 min, cooled in a programmable freezer from 4 to ?80°C at a cooling rate of 5°C/min and thawed at 50°C for 6 s. With this protocol, the immediate post‐thaw trochophore survival was 23 ± 14%, and survival to D‐stage was 27 ± 14%. This is the first report on larval cryopreservation in the hard clam and would have application for genetic breeding and seed production.     

Developmental stages, larval and post-larval growth of angelwing clam Pholas orientalis

Angelwing clam were induced to spawn by thermal stimulation. Mature eggs measured 50 μm in diameter. Cell division occurred within 36 min after fertilization. Mobile trochophore larvae were seen after 12 h and larvae developed within 18 h. Reared on a diet of Isochrysis galbana the larvae reached the umbo stage in 6–7 days. On day 10 the foot could be seen and settlement occurred if a suitable substrate was present. The larvae completed metamorphosis into juveniles within 20 days after settling.     

Embryonic and larval development in the semelparous Nereid polychaete Hediste diversicolor (OF Müller, 1776) in Norway: Challenges and perspectives

Knowledge of broodstock manipulation, gametogenesis, artificial fertilization and larval nutrition is a prerequisite to reach a large‐scale production of the polychaete Hediste diversicolor. In this study, the characteristics of oogenesis and spermatogenesis and embryonic and larval development were observed. Moreover, the effect of temperature on embryonic development and effect of diets and sediment on earlier juvenile development were tested. Mature oocytes were characterized by a spherical shape with a diameter of about 200 μm. They showed radial symmetry with a large centric nucleus surrounded by four distinctive layers. Embryo cleavage started between 4 and 10 hr after fertilization, and developed to the swimming trochophore stage after 5–6 days after fertilization at 11°C. The rate of embryonic development increased with a temperature increase from 6.1 to 21.2°C. The trochophore larvae increased in length from day 9 and commenced differentiation into 3‐setiger stage larvae at day 12. The length growth of larvae until 7‐setiger stage was 0.43 mm/day when fed with fish feed, while those fed shellfish diet and smolt sludge both grew around 0.21–0.23 mm/day. The results suggest that fish feed is a superior diet compared to shellfish diets and smolt sludge for the early larval stage of H. diversicolor.     

Comparison of Development and Larval Growth of Four Venerid Clams

The development and larval morphology of four venerid calms, Ruditapes philippinarum, Mactra veneriformis, Cyclina sinensis , and Meretrix lusoria , which cohabit the intertidal zone in western coastal Korea, were compared using laboratory culture techniques. At 87 μm, the fertilized eggs of C. sinensis and M. lusoria were the largest and at 53 μm, those of M. veneriformis were the smallest. D-shaped larvae of M. lusoriu were the largest and those of M. veneriformis were the smallest measuring at 135 μm and 89 μm, respectively. D-shaped larvae of R. philippinarum and M. lusoria had symmetrical shoulder angles and an elliptical ventral form, in contrast to the asymmetrical shoulder angles and round ventral forms of M. veneriformis and C. sinensis . In general, pediveliger larvae of all species in the study were yellow, but those of M. veneriforks and C sinenis were a more pronounced yellow. In between the early D-shaped and pediveliger stage, 7 and 17 d elapsed for M. lusonia and C. sinensis larvae, respectively. In the early larval stages for all species, the sheU length was longer than the height. However, shell length and height later became approximately the same size in all species except R. philippinarum , which exhibited a flat shape. These results indicate that for these four venerid clams, the different characteristics in larval growth and external morphology provide the evidence necessary for larval identification of natural seed production despite the fact that they spawn concurrently in the intertidal zone.     

大竹蛏生产性人工繁育试验

2007年对大竹蛏进行了生产性人工繁育试验。对亲本不同批次催产效果、不同规格亲本产卵差异、孵化密度进行了比较,研究了D形幼虫发育与温度的关系以及幼虫发育各阶段生长规律等,结果显示,大竹蛏属分批成熟、分批产卵的潜居性贝类,不同批次个体平均产卵量(36~118)×104cell,个体总产卵量294×104cell。壳长8~10 cm的亲贝产卵量大,催产效果好。受精卵适宜的孵化密度为5~10 cell/mL。在水温21~24.5℃条件下,D形幼虫经8~5 d生长,发育变态为附着稚贝。D形幼虫壳长日生长33.33±4.22μm,1 mm前的稚贝壳长日生长108.33±22.57μm,1~10 mm的稚贝平均旬生长量2.12 mm,10.4~30.6 mm的苗种平均旬生长量为2.02 mm。当水温下降到15℃后,大竹蛏苗种生长滞缓。2007年培育出壳长11.52±0.27 mm的稚贝2 165×104cfu,平均成活率12.1%。