不同加工条件下鲍鱼肌肉质构变化

[目的]探究在加工过程中温度和盐渍对鲍鱼肌肉质构的影响。[方法]在实验室条件下研究不同加工温度（809、0、100℃）和不同浓度的盐溶液（3%5、%7、%9、%）对鲍鱼肌肉质构和组织构造的影响,并与新鲜的鲍鱼相比较,从而揭示其质构的变化机理。组织构造变化采用Van Gieson染色法,质构变化采用单轴向压缩和拉伸型流变仪进行分析。[结果]加热处理和盐渍处理对鲍鱼肌肉质构和组织结构有明显影响。物性学特征参数表明,鲜活鲍鱼肌肉具有硬度大,弹性、黏聚性、咀嚼性和恢复性小的质地特点,而加热和盐渍后的鲍鱼肌肉则硬度变小,弹性、黏聚性、咀嚼性和恢复性增大。[结论]为鲍鱼深加工和方便即食食品加工提供了理论基础和试验依据。     

Forecast accuracy of abalone producer prices by shell size in the Republic of Korea: Modified Diebold–Mariano tests of selected autoregressive models

ABSTRACT

This study provides abalone producers and consumers with price forecasting models exhibiting better performance for five classes of abalone prices based on shell size to help farmers predict abalone shipments and enhance the economic activity of consumers. First, the autoregressive-moving average (ARMA) models of abalone producer prices based on information criteria are selected. Second, the best ARMA model using out-of-sample data based on the mean squared error and mean absolute error is determined. Finally, this study compares the predictive accuracy of the better ARMA model and other ARMA models, using a modified Diebold–Mariano test. Higher forecasting accuracy is exhibited by the AR (1,3) model for 8 and 10 abalones per kilogram, the ARMA (1,0) and ARMA [(3),(1)] models for 13 abalones per kilogram, the ARMA (1,0) and ARMA [(1),(2)] models for 15 abalones per kilogram, and the ARMA (1,0) and ARMA (0,1) models for 20 abalones per kilogram.     

我国鲍增养殖现状,问题与发展对策

1982～1988年由于人工育苗技术的不断改进,为鲍生产提供了可供人工养殖及放流增殖的大规格苗种,掀起了鲍人工养殖的高潮,并取得了显著的经济效益。据统计,我国年产量从1985年的100多吨猛增到1995年的1000多吨,但从1990年至今,无论是在人工育苗还是人工增养殖过程中均出现了大量死亡现象,给生产单位造成了严重损失,挫伤了育苗及养殖单位的积极性,出现了大的滑坡。作者对滑坡的原因进行了分析,并对今后的发展提出了一些设想。     

不同配合饲料饲喂鲍鱼效果试验

以海带为对照组,研究3种不同配方、加工工艺生产的鲍配合饲料对室内工厂化水泥池养殖、海上筏式养殖和海上沉箱养殖3种养殖模式鲍鱼生长的影响,结果表明:片状配合饲料Ⅰ、片状配合饲料Ⅱ均表现为在水中稳定性强,能满足现有3种不同鲍鱼养殖模式的需要,饵料系数低于膨化配合饲料Ⅲ和海带,鲍壳颜色为褐绿色。     

螺旋藻粉在鲍鱼配合饲料中的应用研究

试验结果表明，用螺旋藻粉作人工配合饲料的添加剂能明显促进鲍鱼的生长，改善鲍鱼的营养配方，当鲍鱼壳长2．1～3．5cm和壳长3．5～4．5cm时，在其饲料中分别添加5％和10％的螺旋藻粉，均能达到理想的配方效果。     

皱纹盘鲍和刺参与海带筏式混养技术研究

在福建莆田进行了不同密度皱纹盘鲍和刺参与海带筏式混合养殖的试验研究。结果表明:当皱纹盘鲍的放养密度为10个/箱时,其养殖平均产量和产值均最高;当刺参的放养密度为3头/箱时,其养殖平均产量和产值也最高。以皱纹盘鲍和刺参的养殖产量为指标,建立回归方程,分析结果显示:皱纹盘鲍和刺参的最适放养密度分别为11.3个/箱和3.4头/箱。     

莆田市鲍增养殖现状、问题与发展对策

莆田市1993年开展鲍工厂化育苗与养殖工作，养殖规模达到50万粒，年育苗种100万粒，由于工厂化养殖投资高，养殖周期长，生产单位出现亏损，鲍养殖生产随后滑坡。1998年在南日岛开展皱纹盘鲍海区筏式吊养技术，取得了83．53％高的成活率，从而又推动鲍养殖的发展。但从2000年至今，鲍养殖过程中出现大量死亡现象，有的成活率仅为25％，给养殖者带来严重的损失。作者对死亡的原因进行分析，并对今后的发展提出了一些设想。     

The effects of density on the behaviour and growth of juvenile blacklip abalone (Haliotis rubra)

The growth of juvenile abalone in aquaculture is known to be affected by density as a result of competition for food and decreases in water quality. Our results suggest that behaviour is also affected by density and this also has a significant impact on the growth of individual abalone. 1800 juveniles of Haliotis rubra were individually tagged and reared for 5 months in 12 gravity-fed tanks at two levels of density. The experimental design allowed the differentiation of the direct from the indirect effects of density. The abalone growth and distribution was monitored monthly along with the water quality. The distribution of abalone during daytime was closely related to the availability of preferred shelter space. The percentage of abalone stacked on the top of others increased with density. Preferred shelter space was characterized by low light intensity and a corner or edge for the abalone to rest against. Hides at the ends of the tanks were not occupied as much as others. Abalone were found crawling on the side of the tank during daytime when tanks were shaded. Abalone juveniles of 15–60 mm showed fidelity to their resting shelter during daytime but this fidelity was significantly reduced at the higher density. Shading of the tanks totally changed the distribution of the abalone and their daytime behaviour. Competition for shelter space reduced growth more than water quality. This revised version was published online in August 2006 with corrections to the Cover Date.     

Effect of light on oxygen consumption and ammonia excretion in Haliotis discus discus, H. gigantea, H. madaka and their hybrids

Oxygen consumption and ammonia excretion rates of three abalone species, Haliotis discus discus, H. gigantea, H. madaka and their hybrids were measured at 20 °C by incubating for 3 h under dark and light (N = 9–13 for each species and hybrid). Animals were fasted before and during the experiment and measurements were made first under dark followed by light on the next day. The rates increased with the increase in body weight and were higher under light than dark. On average, H. discus discus had higher oxygen consumption (DD; dark = 0.039, light = 0.04 ml/g/h) than H. gigantea (G; D = 0.033, L = 0.036) and H. madaka (M; D = 0.034, L = 0.035); the hybrids had varied patterns with respect to their parental species [DD × M (D = 0.032, L = 0.038); M × DD (D = 0.03, L = 0.038); G × DD (D = 0.035, L = 0.04) and DD × G (D = 0.03, L = 0.034), mother first]. M (0.261, 0.298 μmol/g/h) had the highest ammonia excretion rate while G (0.162; 0.264) and DD (0.229; 0.232) had the lowest under dark and light, respectively. The hybrids had varied patterns in comparison with their parents (DD × M = 0.247, 0.32;M × DD= 0.177, 0.28; DD × G = 0.249, 0.364 and G × DD = 0.116, 0.155). The O/N ratios under both conditions in all species and hybrids indicated that they had carbohydrate dominated metabolism. Results demonstrated physiological variability among the species and hybrids indicating necessity of different strategies for their management and aquaculture.     

Abalone ranching: a review on genetic considerations

Haliotis L. (abalone) is an economically important genus comprising approximately 14 species with commercial value. Unfortunately, due to habitat destruction, overfishing and illegal harvesting, this wild resource is being depleted to unrecoverable status worldwide. To supply the world demand, abalone are cultured in artificial hatchery environments. In the past few decades, attention has been paid to use these artificial environments to the benefit of the species by implementing abalone ranching or reseeding. This is done in an attempt to rebuild the collapsed populations and to prevent further declines in fished stocks. In various countries in which commercial production is in operation, this has been attempted with various levels of success. For ranching to be successful, various factors, however, need to be considered, one of the most important probably being the correct genetic management of such a ranching programme. Genetic management should include using broodstock that are representatives of natural populations, minimizing the effects of hatchery practices on the genetic make‐up of the animals to be released and investigating the genetic impacts of this practice on wild populations. In this review, the genetic management and the effects if management is not implemented are discussed as well as the potential of molecular markers to be used as genetic tags in identifying hatchery‐reared animals.