中国西北地区内陆盐湖卤虫卵径研究

本文研究了新疆维吾尔自治区（简称新疆），青海省和内蒙古自治区（简称内蒙古）20处盐湖卤虫品系的卵径。其结果如下：1．20个卤虫品系中属于两性生殖类型的有13个品系，7个品系为孤雌生殖类型；2．两性生殖类型的卤虫卵径小于孤雌生殖类型的卵径。两性生植类型的卤虫干燥卵径平均为218．2±9．8μm，水合4h后的平均卵径248．9±12．5μm，消亮后的卵径平均为230．4±12．7μm，卵壳厚度平均为9．3±2．4μm。孤雌生殖类型的卤虫干燥卵径平均为245．6±7．6μm．吸水4h后的卵径平均为277．8±7．2μm，消壳后的卵径平均为260.8±6．2μm，卵壳厚度平均为8.5μm。经t值检验．不同生殖类型间的卵径差异非常显著（a＝0．01）。而卵壳厚度，两者之间差异不显著；3．孵出2h内的卤虫无节幼体体长：两性生殖类型平均为440.2±31．0μm，孤雌生殖类型为491．4±20．6μm。经t值检验，差异非常显著。     

三个产地卤虫生长、生殖特征的初步研究

在盐度为20‰和50‰的海水中,分别培养三产地（河北大清河盐场、青海尕海盐湖和美国大盐湖）的卤虫,对其生长和生殖特性进行比较。（1）生长情况：在盐度为20‰的海水中,以河北卤虫生长最快,青海卤虫生长最慢;在盐度为50‰的海水中,以青海卤虫生长最快,河北卤虫生长最慢。（2）生殖情况：在盐度为20‰的海水中,两性生殖卤虫（河北及美国大盐湖卤虫）较孤雌生殖卤虫（青海卤虫）成熟早,且繁殖次数多;而平均每个雌体的繁殖量等参数,两性生殖卤虫与孤雌生殖卤虫均无显著差异。在盐度为50‰的海水中,河北卤虫和美国卤虫在繁殖参数上无显著差异。     

中国西北地区内陆盐湖卤虫染色体倍性 组成的研究

本文研究了新疆维吾尔自治区（简称新疆）、青海省和内蒙古自治区（简称内蒙古）19个卤虫品系的染色体倍性组成。其中属于两性生殖类型的卤虫有13个品系，孤雌生殖类型的卤虫有6个品系。13个行两性生殖品系的染色体为：二倍体，2n＝42，6个行孤雌生殖品系的染色体，既有二倍体2n＝42，又四倍体，4n＝84和五倍体，5n＝105。一部分细胞的染色体表现非整倍的特点。     

影响卤虫产卵量的几个因素

<正> 卤虫过去称盐水丰年虫,俗称丰年虫,是生活在高盐水域中一种小型的低等甲壳动物。卤虫雌雄异体,平常所见者多为雌体,雄性很少见到。雌体腹部有卵囊,用来储存发育成熟的卵子。卤虫的繁殖有两种方式,春夏季节水域环境条件优越稳定时行孤雌生殖,产生夏卵,夏卵壳薄,无需受精,就能够迅速发育成无节幼体,成为雌虫,这种繁殖方式有利于卤虫种群的扩大。夏末秋初雨季以后,气温下降环境改变,雄体出现,雌雄交尾产     

影响卤虫（丰年虫）卵孵化率的一些因子及其流水孵化工艺

卤虫即盐水丰年虫(Artemia saliva)，是目前国内外用于培育蟹、虾类幼体的良好饵料之一，有关其资源及提高孵化率的方法已有报道(1975年，陈清潮等)。本试验是为解决卤虫无节幼体的大量生产，进行盐度、密度、温度等因子对卤虫休眠卵孵化影响的试验，并在此基础上，于1978年提出了流水孵化卤虫休眠卵的新工艺，使单位水体卤虫卵孵化无节幼体的产量提高了数十倍。     

查干淖尔卤虫生物学特性的研究

查干淖尔卤虫属两性生殖种群,繁殖方式属卵生、卵胎生混合型;食物由有机碎屑、嗜盐菌及藻类组成;干燥卵径为213 4±9 3μm;壳厚为7 8μm;克卵量为25 31万粒/g。     

卤虫(Artemia salina)形态习性的初步观察

本文利用我国北方塘沽盐场产的卤虫(Artemia salina)休眠卵作为孵化培养的试验材料,对卤虫的形态进行解剖观察并作详细叙述。卤虫以单细胞藻及有机碎屑为饵。一生中经过无节幼虫期、后无节幼虫期、拟成虫期和成虫期的变态过程。在这一过程中要经过多次蜕皮,每蜕皮一次,身体就长大一次。雌雄虫的形态区别主要在于第二触角和生殖器官。雄虫一般极为少见。雌虫产两种类型卵子:休眠卵和非休眠卵。后者为孤雌生殖。卤虫的生长和性成熟与其水温等有关系。水温高,生长成熟都比较快。水温还和休眠卵的孵化速度有关。平均水温20.8℃时,经46小时开始孵化;25℃经24小时开始孵化;29.5℃经12小时开始孵化。孵化水的波美氏度(卤度)以4—5度最为合适。在缺乏光照时,孵化率大为下降。卤虫无节幼虫是世界海产鱼、虾幼体的著名活饵料。因此,对其孵化、培养条件的进一步探讨是很有必要的。     

孵化卤虫冬卵的技术要点

孵化卤虫冬卵的技术要点卤虫又名丰年虫，是虾蟹幼体十分理想的饵料。在人．育苗生产中，卤虫的孵化率对育苗效果的好坏和生产成本的高低有着直接的影响，因此采取正确有效的孵化方式是十分必要的。一、孵化容器的大小：卤虫卵孵化容器的形状有圆形、方形和圆锥形等，其大...     

卤虫去壳卵在河蟹育苗中应用的研究

本文比较了卤虫去壳卵、无节幼体和人工合成饵料在河蟹育苗中■Ⅲ～■Ⅴ期的饵料效果，探讨了卤虫去壳卵替代无节幼体在河蟹育苗中应用的可能性。     

两种卤虫休眠卵的终止滞育及休眠卵的诱导发生

诱导大盐湖卤虫（Artemia.francisana)和东营卤虫（Artemia.sinina)产休眠卵，作为研究对象探讨了最适终止滞育的方法，结果表明：用20℃冰冻20d，3%的H2O215min处理对大盐湖卤虫休眠卵最有效，而4℃下饱和卤水浸泡25d对东营卤虫休眠卵最有效，研究还发现在不同盐度和温度的组合培养条件下得到的休眠卵，用同一种终止滞育方法处理后，其孵化育不同。     

中国不同地理品系卤虫卵主要营养成分的数值分类

以主成份分析和聚类分析的方法，对中国２５个不同地理品系卤虫卵的营养成分（脂类、氨基酸、蛋白质、维生素）进行了分析和研究。实验结果显示：（１）通过对不同地理品系卤虫卵的４３个营养因子的主成分分析和聚类分析可把２５个不同地理品系卤虫卵分为二个大的类群：海水型和淡水型卤虫卵。（２）Ｃ２０：５ｎ－３、Ｃ１８：３ｎ－３、蛋白质含量、Ｃ１６：１、四种营养成分的含量是区别不同地理品系卤虫卵的主要营养特征。（３）生殖方式不影响各品系的营养成分的组成，而地理品系间营养成分存在差别。（４）淡水型卤早虫卵适合于投喂淡水养殖动物，而海水型卤虫卵适合于海水型养殖动物。     

Molecular systematics of bisexual Artemia populations

To help resolve phylogenetic relationships among bisexual Artemia populations, phylogenetic analysis was conducted using DNA sequences from the nuclear DNA internal transcribed spacer 1 (ITS‐1) and portions of the mitochondrial genome corresponding to the cytochrome oxidase I (COI). DNA sequences were generated for nine bisexual Artemia populations living in different regions of the world. Phylogenetic trees based on ITS‐1 and COI sequences indicated that bisexual Artemia populations consist of four groups. The bisexual Artemia populations from Tibet and Kazakstan always clustered with Artemia urmiana in the same group; there is small sequence divergence and genetic distance among them. Therefore, we deduced that bisexual Artemia populations from Tibet and Kazakstan may belong to the A. urmiana group. Our study did not support that bisexual Artemia populations from Tibet are a new, separate species A. tibetiana. We also found that A. sinica and A. urmiana have a small genetic distance. Based upon these findings, we conclude that A. urmiana may have played an important role in the evolution of A. sinica.     

The Use of Decapsulated Cysts of the Brine Shrimp Artemia as Direct Food for Carp Cyprinus carpio L. Larvae

Decapsulated Arremia cysts have been evaluated as a direct food source for larvae of the carp Cyprinus carpio L. All decapsulated cyst diets gave excellent survival of carp larvae during the first two weeks of culturing. Unlike traditionally brine-stored decapsulated cysts, dried Artemia embryos provided growth results comparable to those obtained with freshly hatched Artemia nauplii. Furthermore, except for Artemia embryos that lost their hatchability after long-term storage in air, several other inactivation treatments, simulating improper harvesting and processing of cysts, did not produce a significant decrease in the nutritional quality of the decapsulated cysts.
Using decapsulated cysts 89 a direct food source for carp larvae, instead of nauplii, the quantity of cysts needed can be reduced by about 25% to 35% after one and two weeks of culturing, respectively. Moreover, the use of decapsulated cysts advances the possible commercialition of poor-hatching and less expensive cyst products for culture of carp larvae.     

The potential of dried, low-hatch, decapsulated Artemia cysts for feeding prawn post-larvae

Low-hatch, decapsulated Artemia cysts were assessed as feed for Penaeus indicus post-larvae (PL) 1–15 days old and the problems resulting from the incorporation of decapsulated cysts into compounded feeds were evaluated. Growth and survival of PL fed on decapsulated cysts (AC) were comparable with Artemia nauplii fed PL (control) and significantly (p < 0.05) higher than observed amongst PL fed on two granulated commercial diets (G150 and G300) or a commercial flake feed (AC-F) incorporating decapsulated cysts (80%). PL fed on artificial diets showed poor growth and delay in metamorphosis. However, survival of PL fed on AC-F was significantly higher (p < 0.05) than that observed amongst granulated feeds. Decapsulated cysts processed into a granulated feed (AC-G) or dried at 90°C (AC-90) also resulted in slow growth and survival when fed to PL. Overall, artificial feeds showed poor water stability and significantly higher leaching of soluble protein and carbohydrates than decapsulated cysts. AC-90 cysts also showed a high level of bursting and leaching of material. This indicates that low-hatch Artemia cysts retain a living membrane after commercial decapsulation and drying prevents loss of highly digestible nutrients, which allows PL growth equal to that on PL fed live Artemia nauplii. Survival of PL was negatively correlated with leaching of soluble protein (p < 0.05), but no correlation was observed for leaching of carbohydrates or between growth and loss of both soluble nutrients. Hence, availability of digestible protein is critical and may influence survival of early stages of post-larval development. Water stability of artificial feeds is an essential factor in promoting efficient nutrition of PL, but other aspects related to heating during processing of feeds also appear to have a deleterious effect on nutritional quality of compounded feeds. Commercially dried, encapsulated Artemia cysts from low-hatch strains remain alive and are highly nutritious for feeding early stages of post-larval prawn but even after death may support acceptable survival when incorporated into a flake diet. © Rapid Science Ltd. 1998     

Evaluation of Protein Quality in Microbound Starter Diets Made with Decapsulated Cysts of Artemia and Fishmeal for Fish Larvae

Abstract.— The protein quality of carboxymethylcellulose microbound diets (MBDs) made with decapsulated cysts of Artemia andlor fishmeal as protein sources was used as an indicator of their suitability as starter feed for fish larvae. Studies on the proximate, fatty acid and amino acid composition. in vitro protein digestibility. diet solubility, and protein structure were combined with an in vivo feeding experiment with African catfish Clarias gariepinus larvae to evaluate the protein quality of the MBDs and a commercial diet. The growth of catfish larvae was higher when fed Artemia -based MBDs than with fishmeal-based MBDs, despite the higher protein and amino acid content of the latter. The in vitro protein digestibility was high for all the MBDs in comparison to a commercial diet. Differences were found in the protein molecular weight among the diets. Most of the proteins in the fishmeal-based diets had low molecular weight in the range between 7.4 and 49.2 kDa. The Artemia-based MBDs had larger protein fractions between 29.4 and 82 kDa. Decapsulated cysts improved the utilization of the MBDs when used in combination with fishmeal. Besides the effect of chemical attractants, the explanation for the positive effect of Artemia has yet to be elucidated. However, attention should be given to interactions between nutrients (e.g., protein-lipid) in live food, which might have an effect on the functional properties of food proteins.     

Chemical Decapsulation of Artemia franciscana Resting Cysts Does Not Necessarily Produce More Nauplii

Decapsulation of Artemia spp. cysts in strong hypochlorite solutions reportedly increases the number of nauplii that hatch. Commercial cysts of Artemia franciscano were subjected to four decapsulation methods prior to hatching them in aerated seawater. Samples were removed from the hatch vessels every 5 h from 15 through 45 h, and fully hatched nauplii were counted. The experiment was performed three times. No significant difference was seen between mean numbers of control nauplii and nauplii obtained using the decapsulation method that yielded the best hatch: oxidation for 15 min in equal parts Clorox® and seawater plus 6 mL of a 40% NaOH solution, followed by reduction with 100 mL of 0.7 M sodium thiosulfate. A third treatment was inferior to either of these, and two others produced very low yields. It was concluded that of the methods evaluated, none is superior to no treatment at all, and some are clearly detrimental to developing Artemia embryos.     

中华卤虫家系构建几个关键技术探讨

本文就中华卤虫(Artemia.sinica)家系构建的几个关键技术进行了具体的讨论。交配产卵阶段基本参数研究结果表明,多数家系在抱对后24~60小时便开始产卵,平均间隔时间为55.68小时,具有较好的产卵及时性,同时有效地排除了假性交配现象,保证了在第20日龄时测定各性状值后建立家系、统计交配、产卵数据的准确性。各家系产卵情况统计结果表明,以生产2批卵的家系最多,46个,以产卵总量在151~200粒之间的家系最多,26个,产卵总量大于150粒的家系为70个,完全满足家系构建的需要。半同胞家系方面,在全同胞家系获得足够数量休眠卵的基础上,对仍在抱对的家系采用人工分离抱对雌雄个体的方法进行半同胞家系的组建,以便实现半同胞家系构建的同步性。本试验各生产阶段基本参数的获得,对指导中华卤虫构建家系进行遗传选育提供了理论依据。     

Heat treatment affects protein quality and protease activity in decapsulated cysts of Artemia when used as starter food for larvae of African catfish Clarias gariepinus (Burchell)

Decapsulated cysts of Artemia subjected to different heat treatments (40, 60, 80 and 96 °C) were fed to African catfish Clarias gariepinus larvae. Heated cysts, untreated cysts and live Artemia nauplii as control constituted the experimental diets. Protein denaturation and solubility, total alkaline protease and specific trypsin activities in the cyst diets were evaluated. The growth of catfish larvae and the proteolytic activity of larval samples during development were also determined. Heat treatment of cysts increased protein denaturation and decreased protein solubility. The protease activity in the cyst diets decreased with higher heating temperatures. The growth of catfish larvae differed according to the diet; higher fish growth was achieved with nauplii and cysts heated at 40 °C. The digestive enzyme activity in larval samples remained similar in all dietary treatments during larval development. The quality of food protein and the way this protein is processed might be more important for successful larval growth than exogenous enzyme supply.     

First biogeographical survey of Artemia in Tanzania

ABSTRACT

In an Artemia survey conducted along the coast of Tanzania between March and July 2017, 32 salt pans in Tanga, Dar es salaam, Pwani, Lindi, and Mtwara were assessed. Of all visited salt pans, 16 (50%) had either Artemia biomass or cysts or both. Body length ranged from 4.0 mm to 9.5 mm, while the mean and modal lengths were 6.2 mm and 6.0 mm, respectively. Temperature ranged from 27.2°C to 48.7°C, salinity from 20 g L^?1 to >140 g L^?1, pH from 5.8 to 7.8, dissolved oxygen (DO) from 3.1 mg L^?1 to 4.9 mg L^?1, water depth from 10 cm to 75 cm and conductivity from 42.0 ms cm^?1 to 176.6 ms cm^?1. A bisexual population of Artemia franciscana is suggested. Observed cyst states included concave, biconcave, spherical and cracking cysts. This is the first to report on the occurrence of Artemia in Tanzania.