Effects of elevated pCO2 on the early development of the commercially important gastropod,Ezo abalone Haliotis discus hannai

We used an up‐to‐date, a high accuracy CO₂ manipulation system to investigate the sensitivity of organisms to CO₂ acidification, rearing marine calcifiers under elevated CO₂ in running water. We evaluated the effects of elevated partial pressures of carbon dioxide (pCO₂) in seawater on larvae of the commercially important marine gastropod Ezo abalone Haliotis discus hannai. In larval Ezo abalone, no effect of exposure to <1100 μatm pCO₂ seawater was observed in fertilization, malformation, or mortality rates until 15 h after fertilization. However, compared to control larvae in seawater (450 or 500 μatm pCO₂), the fertilization rate and the hatching rate (15 h after fertilization) decreased with increased pCO₂ exposure (1650 and 2150 μatm pCO₂) and the malformation rate increased significantly, with the larval shell length being smaller 75 h after hatching. These results suggest that ocean acidification will potentially impact the marine population of Ezo abalone as a human food source in the future.     

开放海区养殖鲍新技术效益分析

为发展离岸开放海区鲍养殖产业,拓展养殖空间,对兴化湾新近开发的开放海区与传统遮蔽海区,延绳式PVC管养新技术与传统筏架式筐养技术的效益进行了分析比较.结果表明,经济效益以开放海区PVC管最高,其次为开放海区塑料筐,最差为遮蔽海区塑料筐,投入产出比分别为1:2.78、1:2.23、1:1.07.遮蔽海区塑料筐和开放海区塑料筐需要再延长272 d和136 d才达到开放海区PVC管商品规格,其预计投入产出比分别为1:1.82、1:2.73.养鲍主要成本为人工费和饲料费,通过养殖容器改造,可节约人工费33.3％;实施鲍藻可节约饲料成本28.1％～34.77％,投入产出比可达到1:3.61～3.71.延绳式PVC管鲍养殖新技术,既可克服开放海区养鲍技术问题,又可产生可观的经济效益,其模式值得应用推广.     

Variability and relationships between flow preference,aggregation size and forage frequency,duration and trajectories of juvenile Haliotis discus hannai Ino

The behaviour of individual abalone in a population is known to vary, and higher levels of activity are linked to better survival rate and faster growth. Considering that continuous illumination at night may cause stress to the abalone which would affect their behaviour over time, in this study observations were made under brief and minimal illumination. The observation lasted for 30 days. The relationships between activity traits were analysed in juvenile Haliotis discus hannai Ino, such as forage frequency, duration and trajectories; flow preference; and aggregation size. The aim was to identify an indicator of the abalone activity status, with the ultimate objective being to provide activity‐related data that might be useful in farm rearing. Ten traits related to locomotion behaviour of 47 juvenile abalone were recorded under laboratory conditions. The results showed that the exploratory level varied between individuals. More exploratory individuals foraged more frequently, spent more time outside hides, started foraging earlier and preferred higher water flow rate than less exploratory individuals. More exploratory and less exploratory individuals also differed in their extensive movements, hide‐shift frequency and aggregation size.     

鲍养殖生物学研究进展

鲍养殖业的深入发展,使鲍养殖生物学的研究日显突出。结合国内外最新研究动态,对鲍的摄食习性、能量收支、遗传育种、病害等养殖生物学研究成果进行了系统的阐述和总结,并展望了有关课题的研究前景。     

Suitability of cage culture for Pacific abalone Haliotis discus hannai Ino production in China

Pacific abalone (Haliotis discus hannai Ino) aquaculture is a thriving industry in China. This study describes a novel submerged cage culture system for abalone rearing in Fujian, South China. The cage consisted of five vertical slots that were oriented perpendicular to the flow of water. The slots were separated by six vertically connected plastic plates for abalone attachment and shelter at the bottom of the cage. Experiment 1 was designed to determine the appropriate stocking density at the start of the abalone sea‐based production cycle. Eight‐month‐old hatchery reared and size‐graded juveniles were transferred to the sea‐based culture system. For different stocking densities, shell length of juveniles obtained in this novel culture system on 2, 3.5 and 5 months, respectively, was compared with shell lengths obtained in a traditionally multi‐tier basket culture system. In Experiment 2, daily growth rates (DGRs) in shell length and biomass in terms of wet weight of 2‐year‐old abalones reared in cage and tiered basket culture systems were compared over a 6‐month period. Results of Experiment 1 showed that growth of abalone in the cage culture system is density‐dependent; the mean final shell length of juveniles obtained was 6.7–15.9% higher than in tiered baskets system even at the same initial stocking density. In Experiment 2, DGRs in shell length of 53.83–78.38 μm day^?1 obtained in cage system were significantly higher than that in tiered baskets (P < 0.01). And in terms of wet weight biomass, it was 1.48–3.01 times higher in the cage system compared with the traditional system. Abalone survival was more than 87.5% in both culture systems in both experiments. Advantages of the newly established cage culture system included better growth performance of the animals reared and potential improvement of rearing conditions, such as improved water flow velocity and dissolved oxygen.     

Parentage assignment in hybrid abalones (Haliotis rufescens × Haliotis discus hannai) based on microsatellite DNA markers

Parentage analysis in aquaculture determines genealogical relationships between broodstock and progeny when the parents are unknown. Thus, parentage analysis is a useful tool to establish pedigree reports in molecular‐assisted selection programs. Here, we evaluated 10 heterologous microsatellite markers for parentage assignment in abalone hybrids produced from 43 abalone broodstocks of red abalone (Haliotis rufescens) and Japanese abalone (H. discus hannai). The allele frequencies, exclusion probabilities and broodstock contributions were calculated using CERVUS, PAPA and GERUD software. The polymorphic information content (PIC) values showed that most of the microsatellite loci were highly informative (>0.7) and more than 90% of parentage assignment was possible with a minimum of 5–6 microsatellite markers. Parentage assignment for hybrid and pure‐red progeny showed a better performance than pure‐Japanese progeny. This result could be due to the high level of allele loss in the parental genotypes. In addition, results indicated that only two sires contributed over 80% and 90% of red and hybrid progenies, respectively. This study gives a new molecular tool to support marker‐assisted selection in abalone hybrids produced in Chile.     

Effects of dietary substitution of fishmeal with the combined dry microalgae,Nannochloropsis oceanica (NO) biomass residue and casein on growth and body composition of juvenile abalone (Haliotis discus)

The effects of dietary substitution of fishmeal with the combined dry Nannochloropsis oceanica (NO) biomass residue and casein on growth performance and carcass composition of juvenile abalone was determined. One thousand two hundred and sixty juvenile abalone were randomly distributed into the 18 L plastic rectangular containers. Five experimental diets in triplicate were prepared. The 28% fishmeal was included into the control (Con) diet. The 25%, 50%, 75% and 100% fishmeal were substituted with the combination of graded levels of dry NO biomass residue and casein, referred to as the NO25, NO50, NO75 and NO100 diets respectively. Finally, the salted sea tangle (ST), Laminaria japonica was prepared to compare the effect of the experimental diets on performance of abalone. The essential amino acids, such as isoleucine, leucine, phenylalanine, threonine and valine tended to increase with dietary substitution of fishmeal with NO biomass residue in the experimental diets. Arginine tended to decrease with dietary substitution of fishmeal with NO biomass residue. Survival of abalone fed the experimental diets was higher than that of abalone fed the ST diet for 16 weeks. Weight gain and specific growth rate (SGR) of abalone fed the NO100 diet were higher than those of abalone fed the all other diets. Weight gain and SGR of abalone linearly increased with dietary substation of fishmeal with NO. Shell length of abalone tended to increase with dietary substitution of fishmeal with the combined dry NO biomass residue and casein. The chemical composition of the soft body of abalone was different among treatments except for moisture content. In conclusion, fishmeal in the diets for abalone could be completely replaced with the combined dry NO biomass residue and casein when the 28% fishmeal was included.     

用海星棘皮作养鲍饵料添加成分的研究

测定了罗氏海星棘皮的组成成分,并用脱毒处理后的海星进行了毒理试验。海星棘皮干粉中含有１０种必需的微量元素,脂质含量为６．３１％,蛋白质含量为５５．０１％,１０种必需、半必需氨基酸占所含氨基酸总量的４９．８２％。将脱毒处理后的海星棘皮烘干粉碎成粉末,分别以２０％,２５％,３０％掺入国产鲍鱼饵料中喂养鲍鱼,并与日本鲍鱼饵料作对比实实验,喂养效果相似,加３０％者喂养效果最好,可以替代进口鲍鱼饵料。     

皱纹盘鲍三倍体诱导条件及其室内饲育试验

皱纹盘鲍(Haliotis discus hannai)是我国重要的海洋经济贝类之一,近年来北方沿海已开展了人工养殖。但普通二倍体鲍需生长3—4年才能达到商品规格,养殖周期长。由于三倍体的不育性,其能量可全部用于生长,这对改善鲍的生长,缩短养殖周期有着积极的意义。有关鲍三倍体的研究起步较晚,在国外,Arai等[1986]、林崎孝志[1989]分别报道了用温度休克和静水压法及细胞松弛素B诱导皱纹     

不同密度的仿刺参与皱纹盘鲍和紫贻贝混养试验

在水温15.0～23.0℃、容积50L(45cm×31cm×30cm)的塑料水槽中,分别放养3组共15头单重2.24g的仿刺参和3个单重19.99g的紫贻贝,再分别混养2组共5个单重8.75g的皱纹盘鲍,定期投喂海带。120d的饲养表明,混养组间鲍的特定生长率差异不显著(P>0.05),但显著低于单养组(P<0.05),混养C组鲍的成活率显著低于其他组(P<0.05)。混养组中海参的成活率差异不显著(P>0.05),但生长速度随密度增加而降低(P<0.05)。将海参产量计算在内,3种密度下,鲍的饲料系数分别降低11.84%、4.03%和4.51%;海参的放养密度为3个/箱时,鲍的饲料系数接近单养鲍;紫贻贝生长停滞,成活率随海参密度的增加而降低。