美济礁合浦珠母贝吊笼养殖试验

在南沙美济礁开展了合浦珠母珠贝吊养试验,试验设计了1.5、2.5m和6.5m3个不同的养殖水深。养殖60d后,测量合浦珠母贝的壳长、壳高和壳宽,统计成活数,计算3个性状指标的特定生长率,比较不同水深合浦珠母珠贝的特定生长率和存活率。试验结果表明,吊养水深对壳宽特定生长率的影响不显著(P0.05),而吊养水深对壳长特定生长率和壳高特定生长率有显著影响(P0.05),6.5m水深的壳长特定生长率(1.10±0.11)%/d和壳高特定生长率(0.92±0.16)%/d均显著高于1.5m的壳长特定生长率(0.82±0.13)%/d和壳高特定生长率(0.50±0.08)%/d;吊养水深对合浦珠母贝的成活率也有显著影响(P0.05),吊养在6.5 m的深度条件下成活率最高(95.00±1.63)%,2.5m水层次之,而在1.5m水深合浦珠母贝的成活率最低(43.25±5.38)%。综合特定生长率和成活率数据可知,在深远海吊养合浦珠母贝时6.5m水深较适合。     

珠母贝人工苗中间培育的研究

2004年6-9月,分别采用不同养殖方法、光照度和水层对珠母贝人工苗进行中间培育。试验结果表明:不同养殖方法的成活率和壳高存在显著的差异(P<0.05),拱形笼吊养法、柱形笼吊养法、网箱法、开放式吊养法成活率分别为9.4%、27.3%、24.5%、0,壳高分别为26.5、31.4、29.8 mm、-,拄形笼吊养法和网箱法生长快且成活率较高;不同光照度对稚贝的壳高和成活率的影响显著(P<0.05),自然光组、800~1000 lx、300~500 lx成活率分别为24.7%、29.6%、36.5%,壳高分别为29.8、28.3、33.6 mm;2~3 m、4~5 m、6~7 m、8~9 m水层成活率分别为27.3%、29.1%、33.6%、38.9%,随着水层的加深而提高(P<0.05),壳高分别为31.4、30.6、29.5、30.2 mm,差异不显著。     

大珠母贝人工苗水泥池中间培育技术的初步研究

为了解决大珠母贝幼贝海区养殖大规模死亡问题，开展了贝苗水池中间培育技术研究。本实验共用3批人工繁殖的2～3mm贝苗，经6个月的水泥池（335m^2）养殖，平均壳长分别增长至35．8mm、27．7mm、23．4mm，平均壳高分别增长至30．1mm、24．9mm、20．1mm，成活率分别为29．5％、17．4％、17．9％。该试验表明，大珠母贝种苗池塘中间培育生长速度快，成活率高，有望克服海区养殖大规模死亡问题。     

日本海神蛤人工繁殖及早期生长发育

为探究日本海神蛤规模化人工苗种繁育的可行性,在国内首次开展了日本海神蛤人工繁殖及早期生长发育研究,结果显示,日本海神蛤繁殖盛期为5月和10月,单次产卵量为300~500万粒/枚,卵径为75~85μm。春季人工将水温升至18.6~19℃, 15~18日龄幼虫生长缓慢,壳长生长率仅为1~3μm/d。其他各日龄幼虫壳长生长率为9~15μm/d。日本海神蛤变态后,再经过30~40 d培育,平均壳长可达（4.94±0.93）mm,稚贝壳长生长率为50~167 μm/d,平均苗种产量为2 695粒/m3。秋季水温17.4~13.2℃条件下,日本海神蛤幼虫相对春季生长发育较慢,经过148 d的培育,稚贝平均壳长可达（2.88±0.47）mm,平均苗种产量为6 666粒/m3,再经室外池塘中间育成后,可培育平均壳长（13.22±2.39）mm幼贝。比较发现在我国北方秋季可培育出适于底播养殖的大规格苗种,且培育成本较低。本研究为我国日本海神蛤苗种繁育、高效养殖及资源修复提供了科学依据。     

厚壳贻贝人工繁殖技术的研究

厚壳贻贝(Mytilus coruscus)是我国贻贝的主要养殖品种,其苗种主要依靠天然苗种和半人工采苗获得。2006年浙江海洋学院于嵊泗县石柱育苗厂,首次突破了厚壳贻贝规模化全人工繁殖和稚贝海区中间培育技术。研究结果表明,厚壳贻贝亲贝通过室内强化培养,经人工催产可获得成熟受精卵,受精率可达95%。在水温16℃时,受精卵在受精后25min出现第一极体,受精后39h50min发育至直线绞合幼虫期,胚胎孵化率达92%,在水温15.8～21℃的条件下,经39d室内人工培育,获平均壳长0.694mm的附着稚贝1304.7×104ind;附着稚贝经102d海区中间培育,获平均壳长13.95mm的稚贝404.46×104ind,海区保苗成活率达31%。该研究结果为今后厚壳贻贝大规模苗种生产奠定了重要理论和技术基础。     

大竹蛏生产性人工育苗技术研究

2009-2011年进行了大竹蛏人工育苗技术的研究。2011年主要进行大竹蛏生产性人工育苗,分别在51m^2和312m^2附着面积中,培育出平均壳长（6．33±0．369）mm、平均质量规格220枚儋的稚贝3．12×10^6枚;（1．04±0．199）mm、477枚／g的稚贝3．28×10^8枚。7月8日开展大竹蛏人工苗种增殖放流,共投入平均壳长3mm的人工苗种1．4亿枚。     

菲律宾蛤仔滩涂生态养殖技术

为研究菲律宾蛤仔的滩涂生态养殖技术,在长江口以北的黄海海区滩涂进行了菲律宾蛤仔砂仔苗、白仔苗及中仔苗3种不同规格苗种的生态养殖试验。试验结果:大面积增养殖条件下,砂子苗、白仔苗及中仔苗的放养密度分别为2 700、760、667粒·m-2时,捕获量分别为(7.96±0.31)×10-2、(3.03±0.12)、(1.89±0.06)kg·m-2。小面积增养殖条件下,白仔苗和中仔苗的成活率与放养密度呈负相关。另外,滩涂养殖白仔苗经15~18个月养殖可采捕销售,亩产值7272元(15亩=1 hm2,下同);浅海底播养殖中子苗,经11个月的养殖可采捕销售,亩均产值5048元;在大规格苗种培育中,从砂仔苗(壳长1~3 mm)培育到白仔苗(壳长8~10 mm)需7个多月,亩产值1067元。     

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%。     

日本珍珠贝人工繁殖苗在热带海区的养殖生长观察

日本珍珠贝引进海南陵水热带海区养殖,人工繁殖幼贝苗1·5~2·0mm下海养殖。经1年的养殖生长观察,结果为:平均壳长59·2mm、壳高59·7mm、壳宽20·7mm,平均个体重34·8g;养殖90d,生长速度较快,壳长平均增长值为11·9mm,相对增长率为55·4%;壳高平均增长值11·2mm,相对增长率61·2%;壳宽平均增长值5·9mm,相对增长率为190·3%。壳长、壳高和体重增长之间具有非常显著的相关关系。研究表明,该贝在海南热带海区养殖的生长速度快,是适宜引进的养殖对象。     

大竹蛏稚贝潜砂行为的研究

实验室条件下,研究大竹蛏稚贝的潜砂行为及稚贝规格对潜砂的影响。结果表明,大竹蛏稚贝的潜砂行为可分3个阶段:准备期、潜砂期及结束期。大竹蛏稚贝在壳长3.00～8.50 mm内,规格对潜砂准备时间、潜砂时间及潜砂行为的影响极显著,随着规格变大其潜砂准备时间逐渐降低(10.7～4.0 s);潜砂时间则表现为先降后升,壳长(6.20±0.04) mm组的稚贝潜砂时间最短,约9.7 s;各规格组稚贝的潜沙率均为100%,壳长(5.18±0.11) mm组潜砂率100%且用时最短。建议在大竹蛏增养殖过程中,投放苗种规格宜大于5.00 mm。     

The Effect of On-Farm Production of Various Sizes of Stocker Caffish Ictalurus punctatus on Farm Profitability.

Abstract— The effect of on‐farm production of various sizes of stocker catfish Ictalurus punctatus on farm profitability was compared to profitability of understocking fingerlings directly into multiple‐batch growout production. Vat‐graded catfish averaging 9 × 2 g (10 cm total length) and 27× 8 g (15 cm total length) were stocked into eight 0.1‐ha ponds at 100,000 fingerlingdha. Fish were fed once daily to apparent satiation and harvested 210 d after stocking. There were no significant differences (P < 0.10) in yield, feed conversion ratio (FCR), and survival across treatments. Mean gross yield (× SD) was 9,469 × 852 kg/ha and 8,846 × 2,099 kg/ha; net yield averaged 8,531× 885 and 6,374 × 2,189 kg/ha; FCR averaged 1.8 × 0.1 and 2.4 × 0.7, and survival averaged 38 × 7% and 26 ×11% for the 10‐cm and 15‐m fingerling stocking treatments, respectively. While experimental survival was low, varying survival rates of stockers in the economic analysis did not affect selection of the most profitable stocking strategies. The 15‐cm hgerlings reached a size significantly larger (361× 81 g or 32.8 × 2.2 cm) than the 10‐cm fingerlings (255 × 28 g or 29.6 × 1.4 cm) (P < 0.07). Whole‐farm budgets were developed based on three sizes of farm (65, 130, and 260 ha) and eight production strategies involving the purchase of different sizes of fingerlings for either understocking growout ponds (6,12, or 37‐g fingerlings) or to grow into stockers (114,135, 176, 255, or 361 9). Purchasing 37‐g advanced fingerlings for multiple‐batch production was the most profitable strategy for the three sizes of farm. The second most important profit‐maximizing strategy for larger farm sizes was single‐batch production with 255‐g stockers produced on‐farm, but purchasing 12‐g fingerlings to stock into multiple‐batch production was the second most profitable strategy for the smallest farm. Sensitivity analysis indicated that the results were robust to variation in survival, prices, and other production characteristics. Risk analysis indicated that purchasing 37‐g advanced fingerlings for multiple‐batch production was associated with the lowest levels of economic risk for growout production.     

Larval rearing of hilsa shad,Tenualosa ilisha (Hamilton 1822)

Hilsa, Tenualosa ilisha has received much attention for culture due to decline of the natural population. Lack of knowledge on larval rearing is the bottleneck for its culture. This study was aimed at developing larval rearing protocols for hilsa shad. Hilsa larvae (4 days old, 4.76 ± 0.06 mm/0.49 ± 0.01 mg) were stocked in fibreglass‐reinforced plastic tanks (1.7 m³ water volume) at 300, 600 and 1,200 nos/m³ in triplicates in three experimental systems viz., E‐I (circular, 0.567 m water depth), E‐II (circular, 0.962 m water depth) and E‐III (rectangular, 0.567 m water depth) and reared for 46 days. The larvae were supplied with Chlorella vulgaris, Brachionus calyciflorus, mixed phytoplankton and mixed zooplankton during 4–50, 6–25, 8–50 and 26–50 days of their age respectively. In each system, higher (p < 0.05) fry survival at 300 nos/m³ than in higher densities indicates density dependent stress. Circular tanks showed higher survival (13.3%–61.31%) than in rectangular tanks (6.88%–27.26%) in each stocking density, indicating the importance of tank shape for rearing. Water depth affected fry survival in circular tanks (E‐I and E‐II) at 300 nos/m³; at 0.962 m depth, survival was higher (61.31%, p < 0.05) than that of 0.567 m depth (49.93%). Good fry survival was achieved through feeding the larvae initially with Chlorella followed by co‐feeding with Brachionus, mixed phytoplankton and zooplankton and rearing in circular tanks at 300 nos/m³ densities at 1 m depth. This first‐ever larval rearing protocol is useful for mass production of fry to support hilsa aquaculture in future.     

When should pearl oyster,Pinctada margaritifera (L.), spat be transferred from the hatchery to the ocean?

Hatchery propagation of pearl oysters is relatively new and optimal hatchery protocols are still being developed. While in the hatchery, pearl oyster spat are supplied a constant and reliable food source and are protected from fluctuations in environmental conditions and predators. This study investigated the hypothesis that retaining blacklip pearl oyster, Pinctada margaritifera (L.), spat in the hatchery for longer periods, prior to transfer to the ocean, would improve growth and survival during early nursery culture. Results showed that the longer spat were retained in the hatchery, the smaller their average size at grading (3.5 months of age). At grading, spat transferred 3 weeks after settlement had a mean dorso–ventral shell height (DVH) of 9.2 ± 0.4 mm with 34% of individuals retained on a 10‐mm mesh. However, spat retained in the hatchery until 5, 7 and 9 weeks after settlement, had a mean DVH of 9.0 ± 0.4, 7.8 ± 0.3 and 6.3 ± 0.4 mm respectively. Only 10% of spat transferred 9 weeks after settlement were retained on a 10‐mm mesh at grading. The results probably reflect superior nutrition available in the ocean and indicate that pearl oyster spat should be transferred from the hatchery as soon as possible after settlement in order to maximize growth.     

Growth performance of pengba,Osteobrama belangeri (Valenciennes, 1844) and water quality changes during fingerling rearing with varied stocking density in large outdoor concrete tanks

Fingerling rearing of pengba, Osteobrama belangeri, was conducted at varied densities for 90 days in 12 outdoor concrete tanks (10 m × 5 m × 1 m). The tanks, grouped into four triplicated treatments, were stocked with fry at 20, 30, 40 and 50 fry m^‐3; and designated as control, T‐1, T‐2 and T‐3 respectively. Tanks were filled up to 90 cm depth. Evaporation loss compensated fortnightly. Fish sampling and monitoring of water quality parameters done at fortnight intervals. Survival varied between 71.5% and 84.0% in treatments. Both survival and total length significantly reduced with increasing densities from control to T‐2 (p < .05), while no differences were observed between T‐2 and T‐3 (p > .05). Similarly, significant reductions in final body weight and specific growth rate were observed with increased densities and these values further reduced in T‐3 than T‐2 (p < .05). Such results corroborated the inverse relationship between stocking density and growth. Gross biomass yields in two higher densities (T‐2 and T‐3), despite their lower survivals, were significantly higher than the two lower densities. The numbers of fingerlings harvested were 35, 74 and 112% higher than the control in T‐1, T‐2 and T‐3 respectively. The lowest size obtained even at the highest density (T‐3) was of 7.0 ± 1.0 cm and 3.99 ± 0.17 g, which can be considered as ideal grow‐out stocking size of pengba. Therefore, the study showed feasibility of stocking up to 50 fry m^‐3 for rearing from fry to fingerling stage. However, the other lower densities may be used in case of requirement of larger fingerlings.     

六线鱼人工育苗技术研究

使用从海区采集和人工催产获得的六线鱼卵块１０９１ｇ，孵化仔鱼１１万尾，平均孵化率为５６％，仔鱼经４５～６０天培育，育成全长２．５～４．０ｃｍ，鱼种１．８３万尾，平均成活率２４．４％，专家验收认为，育苗量，苗种规格及生长速度均处国内领先水平，对卵块收集，人工孵化，苗种生长，饵料系列，育苗病害，饵料生物培育等问题进行了研讨。     

菲律宾蛤仔2个壳色品系群体杂交的研究

于2007年10月，以F1代海洋红（R）和斑马蛤（Z）为材料，开展了2个壳色菲律宾蛤仔（Ruditapes philippinarum）品系的群体杂交。试验由RR（R♀×R♂）、ZZ（Z♀×Z♂）、RZ（R♀×Z♂）和ZR（Z♀×R♂）组成。结果表明，2个壳色品系亲贝壳长、重量和产卵量差异显著（P〈0．05）。各试验组卵径、受精率和D形幼虫大小元显著差异（P〉0．05），但杂交组孵化率显著高于相应对照组（P〈0．05）。浮游期间幼虫未表现出明显的生长优势，但表现出一定的存活优势。RZ和ZR的生长优势平均值分别为（1．63±0．81）％和（2．58±0．67）％；生长速度分别为（8．64±0．32）和（8．67±0．31）μm·d^-1，显著高于相应对照组（P〈0．05）；存活优势分别为（10．30±1．92）％和（16．30±1．04）％。室内培育期间稚贝表现出明显的生长、存活优势。RZ、ZR的生长优势平均值分别为（11．25±2．98）％和（20．31±2．10）％；生长速度分别为（9．88±1．45）和（10．79±1．32）μm·d^-1，显著高于相应对照组（P〈0．05），存活优势分别为（40．85±9．90）％和（57．08±11．98）％。     

不同家系中华绒螯蟹幼蟹在室外和室内的生长

2015年6月上旬,将3个家系中华绒螯蟹大眼幼体分别饲养在面积为40m2(6.50m×6.15m)的稻田围隔中,每个围隔约2500尾。2015年7月中下旬,随机从中选取各3个家系的幼蟹,放入室内300L的养殖缸(30只/缸)中对比养殖。2015年8—10月连续测量了幼蟹的头胸甲宽、头胸甲长、体质量,用多重方差分析了环境、家系及生长阶段的性状参数。试验结果表明,养殖环境对A家系幼蟹生长性状的影响不显著(P0.05),对B家系则极显著(P0.01),对C家系,除了初始的生长性状影响不显著外(P0.05),其余均存在显著影响(P0.05),表明A家系具有一定的环境适应性。家系因素对幼蟹生长性状参数均存在显著影响(P0.05),表明遗传对于幼蟹的生长具有重要作用。相关分析表明,蟹种的头胸甲宽、头胸甲长在两种养殖环境中均呈极显著正相关(P0.01),相关系数分别为0.314、0.305;体质量呈不显著正相关(r=0.146,P0.05),表明以头胸甲宽、头胸甲长为选育指标得到的后代对两种养殖环境有一定的适应性。     

Rearing advanced fry of major Indian carp species in recirculatory-filtering ponds at Barrackpore,West Bengal

This paper describes an experiment using a recirculatory-filtering system operating in two rectangular cemented ponds (160 and 190 m², 1.5 m deep) to rear fry (25 mm–50 mm) of the major Indian carp species Labeo rohita (Hamilton) and Catla catla (Hamilton) to fingerlings (100 mm–125 mm). These operations were concluded in both the species in 32 days at stocking densities of 0.46 million/ha and 0.55 million/ha, and showed survival rates of 96.6% and 84.4% respectively. In the presently followed practices of modern fish culturists, corresponding operations in earth ponds usually take 90 days and have a stocking density of 0.2 million/ha with survival rates more or less similar to those obtained in the recirculatory-filtering system. If followed by industry, the technique described will enable production of major Indian carp fingerlings with great saving in time, the use of water and the space occupied by the production system. These advantages greatly enhance the economic viability of rearing carp fingerling in India.     

投喂不同海藻饵料对海上网箱幼刺参生长及成活的影响

分别采用鲜孔石莼(Ulva pertusa)、鲜角叉菜(Chondrus ocellatus)、鲜裙带菜(Undaria pinnatifida)磨碎液及其混合液与25%海泥制成四种不同配合饵料,对2.25g±0.02g的幼刺参生长和成活进行了研究。结果表明:实验60d后,投喂鲜孔石莼的幼刺体重增长达到(4.86±0.54)g,特定生长率表现出最大值,为1.36%±0.13%/d,相比对照组(3.42g±0.62g,0.82%±0.34%/d)增长显著(P<0.05),鲜角叉菜次之,体重和特定生长率分别为4.37g±0.31g和1.22%±0.22%/d,两者差异不显著(P>0.05)。幼刺参摄食鲜孔石莼、鲜角叉菜、鲜裙带菜和混合藻液其存活率分别为62.2%±0.2%、58.7%±0.3%、55.3%±0.9%、56.3%±0.7%,与对照组(50.6%±1.3%)之间差异显著(P<0.05)。研究结果显示,投喂鲜孔石莼对海上网箱幼刺参的生长和成活效果最好。因此,在刺参海上网箱养殖阶段添加鲜孔石莼是经济可行的。     

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。