Physiological metabolism of Haliotis discus hannai Ino under different light qualities and cycles

The goal of this experiment was to examine the effects of different light qualities (red, white, blue) and cycles (12L:12D, 8L:16D, 4L:20D, 0L:24D, 16L:8D) on the survival, growth, metabolism and antioxidant defence system of Haliotis discus hannai Ino. Under red and white light at 4L:20D, the body weight‐specific growth rate of abalones was significantly higher than that of the 0L:24D group (P < 0.05). At 16L:8D, succinate dehydrogenase activity decreased and lactate dehydrogenase and alanine aminotransferase activity and the lactic acid content significantly rose (P < 0.05) in the red and white light groups. Under blue light, reactive oxygen species and malondialdehyde content for each light cycle were significantly higher than those of the red and white groups (P < 0.05). Under blue, white and red light, total antioxidant capacity (T‐AOC), superoxide dismutase (SOD) activity, glutathione peroxidase (GP_X) activity and reduced glutathione (GSH) content gradually rose with increased duration of light exposure. Under red light, significant differences in these parameters were detected between the 4L:20D and 16L:8D groups (P < 0.05). Under blue and white light at 16L:8D, values of T‐AOC, SOD, GP_X activity and GSH content were significantly lower than those of the 12L:12D group (P < 0.05). Overall, these results indicate that red light at light cycles of 4L:20D and 8L:16D is optimal for the culture and production of H. discus hannai, as these conditions promoted food intake, growth and health maintenance as well as normal physiological metabolism of the organism.     

2种底栖硅藻饲养杂色鲍幼体和稚贝的饵料效果

用羽纹藻（Pinnularia sp．）、简单双眉藻（Amprhoraexigua）、羽纹藻和简单双眉藻混合（混合组）作为饵料，以自然海区采集的硅藻作对照，研究其对杂色鲍（Haliotisdiversicolor）幼体和稚贝成活和生长的影响，确定人工分离的2种硅藻的饵料效果。结果表明，2种底栖硅藻在杂色鲍育苗中具有一定的饵料价值。饵料种类对不同规格杂色鲍的成活率和生长影响显著，并且2个观测指标的结果相同。幼体羽纹藻组、简单双眉藻、混合组3组间的成活率、生长无显著差异，但都明显比对照组低；稚贝简单双眉藻、混合组和对照组无显著差异，羽纹藻组显著比对照组低。     

Effects of Dual Microalgal Species Biofilms on New Zealand Black-Footed Abalone (Hailotis iris) Larval/Post-Larval Processes

Dual microalgal species biofilms with distinct amino acid characteristics were tested for their effects on abalone (Haliotis iris) initial attachment, metamorphosis, settlement, and survival. Nine microalgal species, isolated from around Auckland, New Zealand, were grown in the laboratory, and used to produce nine dual microalgal species biofilms. Abalone larvae were exposed to the different biofilm treatments and controls (no biofilms) for seven (attachment and metamorphosis) and 14 (settlement and survival) days. The larvae performed significantly better in the dual microalgal biofilms compared to controls, and some biofilms resulted in better attachment, metamorphosis, settlement, and survival than others. For example, the best-performing biofilms almost always contained cyanobacteria (Oscillatoria cf. erythrata, Anacystis cf. aeruginosa, and Schizothrix cf. calcicola), which are attributed with better nutritional values. However, the amino acid profiles did not produce a clear pattern with regard to their effects on the four larval processes. Instead, total amino acid (TAA) content was positively correlated with percentage of attachment and metamorphosis. Greater TAA contents are likely to reflect greater amounts of extra-cellular polymers within the biofilms, which are suggested to improve larval performance.     

皱纹盘鲍与光棘球海胆筏式混养研究

皱纹盘鲍与光棘球海胆的混养可有效地防治污损生物的附着。综合分析鲍与海胆的生长、存活及防污损生物附着的效果，在生长期、高温期和恢复生长期混养海胆的最适密度分别为１５．２０个／格和１５－２０个／格。     

Use of macroalgae supplemented with probiotics in the Haliotis rufescens (Swainson, 1822) culture in Northern Chile

In this study, we evaluate the use of macroalgae as vectors of probiotics bacteria into the digestive tract of abalone to improve their survival and growth. It is shown that when abalone Haliotis rufescens of different sizes were fed with a natural diet composed of fronds of the macroalga Macrocystis integrifolia supplemented with a mixture of Vibrio sp. C21‐UMA, Agarivorans albus F1‐UMA and Vibrio sp. F15‐UMA bacteria, there was a significant increase (P<0.05) in the average monthly growth rate and survival (%)in a period of 210 days, compared with the control without a probiotic supplement. The permanence of the probiotics in the digestive tract of the animals was monitored, and it was found that the number of culturable C21‐UMA and F1‐UMA bacteria decreased significantly (P<0.05) in recently weaned and adult abalone, and they almost disappeared completely on day 19 of the bioassay. However, the culturable Vibrio sp. F15‐UMA disappeared completely from the digestive tract on day 22 of the bioassay, and these were the bacteria that remained at the highest concentration compared with the other two bacterial strains over the experimental period. It is therefore shown that it is feasible to use a probiotic mixture to improve the profitability of the H. rufescens culture.     

Karyotype analysis of interspecific hybrids between Haliotis rufescens and Haliotis discus HANNAI

Evidence of hybridization in Haliotis has been mainly supported by hatchery experiences and collection of wild hybrid abalones among several species from natural populations worldwide. However, despite the importance to understand the role of the hybridization process through Haliotidae evolution, and also its impact on the abalone aquaculture, genetic studies in hybrid abalones have been poorly developed. Herein, cytogenetic approach allows studying the genetic conformation in hybrid organisms at the chromosome level. This paper reports a quantitative karyotype analysis in Haliotis rufescens, Haliotis discus hannai and their interspecific hybrid. Thus, to characterize chromosome pairs and establish cytogenetic comparisons, chromosome banding with distamycin‐A/4,6‐diamidino‐2‐phenylindole fluorochromes and morphologic measurements were performed. The results showed that the hybrids are successfully viable and their karyotypes evidenced a conservative chromosome number of 2n=36. The karyo‐idiogram showed a high correspondence in chromosome pair morphology among the hybrids and their parental species, except for a single heteromorphic pair that corresponds to the chromosome 16 from H. rufescens andH. d. hannai respectively. The implications of the abalone hybrid viability derived from its chromosome composition are discussed.     

Dietary protein requirements for discus (Symphysodon spp.)

Discus (Symphysodon spp.), a valuable ornamental species (mean initial weight 4.40–4.65 g) were fed five isoenergetic (gross energy: 200–209 kJ g^–1), semipurified diets (casein, gelatine and Danish fish meal as protein sources) twice a day to satiation for 12 weeks. Five levels of protein were evaluated (350, 400, 450, 500 and 550 g kg^–1 diet) and each fed to four replicates. Growth rate increased significantly with protein level up to 500 g kg^–1 diet and then decreased. Feed conversion rates (FCRs) ranged from 2.2 to 3.8, varying inversely with observed growth rate. A similar trend was also observed in the efficiency of protein utilization (PER). Analysis of dose (protein level)‐response (growth rate) with second order polynomial regression suggested a requirement of 449–501 g kg^–1.     

中国海耳鲍成熟卵的超微结构

利用光学和电子显微镜对耳鲍排出体外成熟卵的形态及超微结构进行了观察。耳鲍成熟卵具有卵胶质膜、卵黄膜和细胞膜;卵质中含有线粒体、核糖体、内质网及高尔基体等细胞器;还含有高电子密度的分泌颗粒和吞饮小泡。皮层中含有皮质小泡,但未发现中心粒。耳鲍成熟卵没有明显的卵极标志,卵黄颗粒分布较均匀。     

皱纹盘鲍的遗传育种研究进展

皱纹盘鲍为我国北方的重要养殖品种,但随着养殖规模与密度的不断扩大,因种质退化等原因导致暴发性病害频发。因此,皱纹盘鲍的遗传改良研究对于皱纹盘鲍养殖产业的可持续健康发展十分重要。本文对我国皱纹盘鲍（Haliotis discus hannai）的生物学特征、微卫星标记、选择育种、杂交育种、多倍体育种、雌核发育的研究现状进行了综述,并对今后皱纹盘鲍遗传育种的方法和方向作了展望。