西施舌人工育苗试验

浙江西施舌的人工育苗以4月下旬至6月中下旬为宜,重视亲贝促熟技术,实行阴干和流水刺激排放精卵,变态期以沙底质上附着为宜。     

套子湾刺参半人工采苗技术

野生稚参比同期人工培育的稚参体质健壮、肉质肥厚、生长速度快,深受养殖业户的欢迎。养殖栉孔扇贝和牡蛎都能不同程度地采集到一定数量的稚参。受此启发,去年在总结往年生产经验的基础上,我们在套子湾扇贝养殖海区结合栉孔扇贝的养殖和栉孔扇贝半人工采苗生产投挂刺参采苗器,进行了刺参半人工采苗试验,现报告如下。     

西施舌的人工育苗现状及养殖发展前景展望

本文介绍了名贵海产贝类-西施舌Coelomatra antiquata在南海的资源状况、人工育苗技术现状和存在问题，并对其进一步发展应解决的关键技术问题进行了探讨，提出了应研究建立室内立体附苗与稚贝立体培育技术，重点攻克大规格苗种中间培育技术及优化增养殖技术措施等观点，同时对其发展前景进行了探讨和分析。     

北方沿海西施舌苗种的人工培育试验

在辽宁省沿海首次对西施舌室内人工育苗进行了研究。试验结果表明,对西施舌种贝促熟62d,用流水刺激的方法诱导亲贝排放精,卵,亲贝个体排放比例达到60％以上,个体排卵量约为380～420万粒,其受精率为82．0％,孵化率为46．0％。在盐度为25．6～31．0,水温为23．8～25．9℃的条件下,浮游幼虫9～14d进入附着变态期,变态率为12．4％,壳长生长速度为13．9μm／d。变态后的36d内,壳长平均生长速度为76．3μm／d,成活率为80.4％。沙盘单位面积附苗量为波纹板的48．5倍。本次试验利用12m^3水体育出2．5mm的稚贝21．4万枚,单位水体出苗量为1．78万枚／m^3。     

西施舌人工育苗高产稳产技术初步研究

西施舌(Coelomactra antiquata)俗称“海蚌”和“贵妃蚌”，隶属于蛤蜊蝌，腔蛤蜊属的一种大型海产名贵贝类。、本文作者于2002年5月．2003年9月，在广东省汕头市河渡海水种苗中心采取传统的育苗方法，注重水质管理、立体采苗、稚贝强化培育等技术措施，探讨西施舌人工育苗高产途径。本项研究的结果，于2003年7月l8日通过同行专家现场验收，现报道如下，供生产单位参考。     

日照沿海西施舌人工繁育技术

上世纪80年代,西施舌Coelomactra antiquata( Spengler,1802)人工繁育在日照沿海试验成功.近年来,经过日照市水产研究所的科研攻关,突破了稚贝中间培育的关键技术,2011年共获受精卵约3亿粒,孵化D型幼虫2.3亿余粒,孵化率近77％.育成壳长3～9 mm以上西施舌苗900余万粒,圆满完成了日照近海海区西施舌的省级增殖放流任务.     

西施舌稚贝附着基质的初步研究

西施舌（Ｍａｃｔｒａａｎｔｉｑｕａｔａ）隶属于蛤蜊科,营埋栖生活,是颇受欢迎的高档优质食用贝类。自５０年代起,国内外先后进行过西施舌人工育苗的研究［１］１）,并普遍采用砂作为附着基。但现在的潜砂饲育方式属平面式培育,水体的立体利用率低,而且在稚贝附着...     

西施舌Cyt b基因核苷酸差异分析

从线粒体DNA水平对我国沿海西施舌进行了遗传差异和系统发育研究,为其保护和可持续利用提供理论依据.对4个不同地理群体西施舌Cyt b基因片段进行了扩增、测序,利用MEGA4.1进行序列比对分析,以文蛤和中华文蛤为外类群,构建系统进化树.结果获得394 bp的Cyt b基因片段,其T、C、A、G含量分别为38.4%、16.9%、23.6%、21.1%,A+T含量明显高于G+C含量.在394 bp比对位点中,有318个保守碱基,76个变异位点.其中,70个简约信息位点.长乐与其他3个群体之间的遗传距离为0.194～0.209.氨基酸序列比对结果显示长乐群体与3个非长乐群体有7个位点的氨基酸差异,遗传距离为0.053.由此可见长乐群体是一个具有明显分子遗传特征的独立群体.     

西施舌室内人工育苗试验

西施舌俗称海蚌，是一种名贵的海产贝类。营养丰富，在医用上具有润肺、益精补阴、治疗糖尿病的药效。近年来，由于诸多因素，西施舌的自然资源严重衰退，产量逐年下降，已远远不能满足国内外消费者的需求，因此，开展西施舌育苗、养殖有着巨大的潜力。2008年在文登市向源育苗场进行了西施舌室内人工育苗试验，现将试验情况报告如下：     

中国沿海5个自然西施舌群体等位酶的遗传变异研究

采用聚丙烯酰胺凝胶垂直平板电泳技术,研究了中国沿海的山东胶南(JN)、江苏南通(NT)、浙江台州(TZ)、福建福州(FZ)、广西北海(BH)西施舌(Coelomactra antiquata)自然群体的等位基因酶遗传变异,对其斧足、外套膜和肝脏组织进行了13种同工酶的比较实验,最后选择肝脏作为西施舌的等位酶研究组织。选取谱带清晰的8种等位酶进行检测,共检测到17个位点。JN、NT、TZ、FZ、BH群体的多态位点比例分别为58.82%、70.59%、50.00%、56.25%、41.17%,平均有效等位基因数(Ae)分别为1.550、1.555、1.434、1.602、1.828,平均杂合度观察值(Ho)分别为0.240、0.270、0.239、0.243、0.288。结果表明,群体的遗传变异水平BH>NT>FZ>JN>TZ,中国沿海西施舌遗传变异水平较高、种质资源较好;同时发现除浙江台州(TZ)群体外,普遍存在杂合子缺失现象;并根据等位酶资料对5个群体进行了UPGMA聚类分析。     

福建与江苏西施舌群体形态差异研究

对栖息在中国福建与江苏沿海的2个野生西施舌（Coelomactra antiquata）群体进行了形态特征比较,以相同壳长、相同年龄及其壳长、壳高、壳宽、壳质量、檐面长度与宽度等5个数量性状的观测数据为依据,应用4种数理统计方法,对不同群体西施舌进行形态差异的多元分析。结果表明,栖息于福建长乐与江苏如东沿海的西施舌5个可量性状均表现出显著与极显著差异。均数差异系数（C、D）检验值超过1．28,差异达到亚种水平。     

铜在西施舌鳃和消化腺蓄积及对SOD和CAT活性影响

为了研究重金属铜(Cu2+)在西施舌鳃、消化腺组织中的蓄积规律及其对超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性的影响,本文采用急性毒性实验的方法,将西施舌置于不同浓度Cu2+溶液进行实验。结果显示,鳃组织中的Cu2+在第4天时达最大蓄积量,为79.7μg/g,消化腺组织则在第8天蓄积量达最大,为139.2μg/g,Cu2+的最大蓄积均出现在0.16 mg/L胁迫组,消化腺Cu2+浓度蓄积均随胁迫浓度的增加而升高;鳃、消化腺组织CAT活性均呈先升高后降低趋势,且后者CAT活性显著高于前者;鳃组织SOD活性呈先升高后降低趋势,且受到显著诱导(P0.05),消化腺组织的SOD活性则呈下降趋势,在0.16 mg/L胁迫组,鳃和消化腺组织的SOD活性均分别在第3~4天受到极显著抑制(P0.01),表明CAT和SOD活性可作为指示西施舌受Cu2+污染程度的重要指标。     

蛭弧菌对西施舌幼虫生长和培养水质的影响

研究了不同浓度蛭弧菌在西施舌幼虫培养中的应用,在温度26～27℃,以人工授精发育的西施舌幼虫为材料,测定水中氨氮、亚硝态氮浓度和pH值,并计算幼虫的生长速率以及成活率,与对照组进行比较,实验表明,氨氮浓度最多比对照组降低34%(P<0.05),亚硝态氮浓度最多降低25%(P<0.05)。结果表明,蛭弧菌100mg/L为最适浓度,在一定程度上降低水中氨氮和亚硝态氮浓度,并促进西施舌壳顶幼虫的生长,其生长速率高于对照组22%,成活率高于对照组13%,差异显著(P<0.05),但对pH值影响不显著。     

Reproductive cycle,collection and early growth of Aulacomya ater,Molina 1782 (Bivalvia: Mytilidae) in northern Chile

We evaluated the reproductive cycle of Aulacomya ater at Caleta Punta Arenas (Antofagasta, Chile), finding two important spawning periods (August–September and October–November) associated with declining water temperatures. Mytilid collectors were installed at Caleta Punta Arenas and Caleta Errázuriz (250 km further south) in November and then extracted in consecutive time periods. The results showed settlements of A. ater along with Choromytilus chorus (Molina) and Semimytilus algosus (Gould). An analysis of the spat size structure from each period revealed different micro‐cohorts for each species; the micro‐cohorts of C. chorus were predominant. Daily growth rates were estimated using the average sizes of the micro‐cohorts on two consecutive dates. Although the daily growth rates did not vary significantly between sites for a given species, these rates were lowest for A. ater and highest for S. algosus. The abundance and greater growth of C. chorus caused interspecific competition with A. ater that was detrimental to the survival of the latter. We hypothesize the existence of a metapopulation of A. ater in northern Chile that would explain the settlement of four micro‐cohorts on collectors after 28 days at Caleta Punta Arenas, and the settlement recorded after 80 days at Caleta Errázuriz.     

Comparison of faecal collection methods and diet acclimation times for the measurement of digestibility coefficients in barramundi (Lates calcarifer)

This study aimed to investigate the effects of two faecal collection methods (stripping and settlement) on the apparent digestibility coefficients (ADC) of dry matter, protein and energy of three different diets fed to barramundi. In a second experiment, the effect of acclimation time (i.e. number of days fed the diet) on the calculation of ADCs was also investigated. Each tank of fish was fed one of three diets for 12 days. Faeces were collected by both stripping and settlement, although only settlement was used prior to day seven of the acclimation period. Faeces were collected using the settlement method at regular intervals from day 1 to day 12. Comparisons between faecal collection methods were only made based on faecal material collected over a similar acclimation period. The collection of faeces by stripping produced more conservative ADCs, which were also more consistent than those obtained using the settlement technique. The calculated ADCs typically fluctuated for the first 3 days of collection before the variability diminished. Barramundi should be acclimated to diets for a minimum of 4 days before collection of faecal material, and collection by stripping is recommended to obtain the most reliable digestibility data.     

不同盐、碱度下3品系尼罗罗非鱼幼鱼网箱养殖的生长比较

以慢性驯化后的上海、山东、河北品系尼岁岁非鱼（Oreochromis niloticus）幼鱼为试验材料,比较它们在盐度组（0、15和20）、碳酸氢钠（NaHCO3）碱度组（1 g·L^-1、2 g·L^-1和3 g·L^-1）以及盐碱混合组（15,1 g·L^-1;15,2 g·L^-1;15,3 g·L^-1;20,1 g·L^-1;20,2 g·L^-1和20,3 g·L^-1）条件下网箱养殖成活率和日均增重率差异.62d试验结果表明,上海、山东、河北品系尼罗罗非鱼幼鱼在不同盐度、碱度、盐碱混合处理组中的成活率差异不显著（P＞0.05）,而日均增重率的差异显著（P＜0.05）.随着盐度、碱度增加,尼罗罗非鱼生长速度大体呈下降趋势;盐碱混合组生长速度较单盐、单碱组减慢.还发现不同品系尼罗罗非鱼在不同盐碱梯度下表现出不同的相对生长优势.研究结果为尼罗罗非鱼适宜养殖的盐碱范围确定、品系筛选提供了重要的基础资料.     

不同规格和投苗密度对仿刺参池塘网箱保苗效果的影响

仿刺参室外池塘网箱保苗是近年来兴起的一种半生态式的保苗方式。于2014年7—11月在仿刺参室外池塘网箱保苗期间,通过现场试验比较研究了不同投苗规格[大规格(0.093±0.004)g/头,小规格(0.024±0.001)g/头]和密度(低密度125g/m3、中密度250g/m3、高密度375g/m3)两因素对仿刺参苗生长、成活率和产量的影响。结果表明,对于同一规格的仿刺参苗,低密度组体质量与特定生长率高于中、高密度组;相同密度条件下,大规格苗种成活率显著高于小规格(P0.05),小规格低密度组仿刺参苗的成活率显著高于高密度组(P0.05),大规格低密度组仿刺参苗的成活率显著高于中、高密度组(P0.05)。不同密度组收获仿刺参苗的总产量无显著差异(P0.05),但低密度组收获仿刺参苗的净产量高于中、高密度组。通过两因素方差分析可知,规格的主效应及二者的交互作用对仿刺参苗成活率有显著的影响(P0.05),密度的主效应对仿刺参苗成活率有极显著的影响(P0.001);两因素的主效应及其交互作用对仿刺参苗总产量均无显著的影响(P0.05)。规格主效应及二者的交互作用对仿刺参苗净产量的影响不显著(P0.05),密度主效应对仿刺参苗净产量有显著的影响(P0.05)。因此,仿刺参室外网箱保苗过程中投放大规格、低密度苗种能够保证较高的成活率和净产量,而且可以节省苗种资源和饵料投喂量,降低单位面积生产成本和管理成本,提高产出投入比和经济效益。     

Heterosis analysis at early generations for complete diallel crosses in three different geographical culture populations of Sinonovacula constricta (Lamarck 1818) in Zhejiang,China

The paper reports a study focused on breeding new rapidly growing and heat‐tolerant strains in a commercially important Asian bivalve, Sinonovacula constricta. To breed a new strain of S. constricta with fast growth and high temperature tolerance, complete diallel crosses were carried out using three different geographical culture populations from Zhejiang (Z), Fujian (F) and Guangdong (G) provinces, China. Larval and spat growth and the survival and heat tolerance of spats were compared in detail. The experimental serial growth traits extracted from larval and spat measurements (shell length and shell height) indicated that there was no difference between six hybrid crosses and parental crosses at the larval stage; while at the spat stage, some differences were observed. The hybrid crosses ZF (Z♀ × F♂), ZG (Z♀ × G♂) and FG (F♀ × G♂) outperformed the parental groups in shell length at the end of intermediate culture, with lengths of 21.77 ± 0.28 mm, 21.55 ± 0.29 mm and 21.44 ± 0.20 mm respectively. For spat survival rate, the hybrid cross ZF (Z♀ × F♂) had a significantly larger value (88.89 ± 4.16%) than all the other groups, and the hybrid cross ZG (Z♀ × G♂) had a significantly larger rate than the cross GZ (G♀ × Z♂) and parental crosses ZZ (Z♀ × Z♂) and GG (G♀ × G♂). The hybrid crosses ZF (Z♀ × F♂), ZG (Z♀ × G♂) and FG (F♀ × G♂) exceeded the parental groups in heat tolerance, but there was no significant difference. The growth, survival and heat tolerance results showed that the crosses ZF, ZG and FG in this study were the best hybridization combinations for genetic improvement, which could have significant implications for the development of razor clam aquaculture. This work provides a theoretical basis for breeding new varieties (strains) that grow rapidly and are heat tolerant.     

A proposal for modelling the thermal‐unit growth coefficient and feed conversion ratio as functions of feeding rate for gilthead sea bream (Sparus aurata,L.) in summer conditions

Modelling growth as a function of feeding rate (FR) could be one of the most important tools for fish farms, because this knowledge allows growth to be maximized, or the feed conversion ratio (FCR) to be minimized, thereby improving profits. All growth models should include the three principal variables involved in growth: initial body weight, temperature and feeding rate. The thermal‐unit growth coefficient (TGC) already includes water temperature variation and initial body weight. Studying variation in TGC for fish fed the same diet, but at several feeding rates provides interesting information for modelling. Six different trials were conducted where gilthead sea bream of several different initial weights (24, 38, 50, 110, 220 or 289 g) were fed increasing amounts, and growth and the conversion index response were measured. The TGC response was modelled as a function of FR, and both asymptotic and quadratic responses were examined. The asymptotic model, TGC × 1000 = 2.037*(1?e ^{(?0.8*(FR?0.22)}), had an adjusted R² value of 96.18, whereas the quadratic model, TGC × 1000 = ?0.381 + 1,715 × FR?0,382 × FR², had an adjusted R² value of 96.42. Simulations of the FCR and the economical profitability index (EPI) were conducted to provide tools for maximizing efficiency and profitability, and the results suggest that these tools will be useful for future investigations.