生态因子对蚤状潘休眠卵萌发率的影响

蚤状(Daphniapulex)休眠卵在不同生态条件下累积萌发率的结果显示:萌发温度为20℃～25℃时萌发率较高,缺氧保存的休眠卵能够萌发,而有氧保存的不能萌发;曝气自来水作为萌发液萌发率较高,过滤池水较低,而曝气水和休眠卵形成时的原液居于二者之间;休眠卵缺光几乎不能够萌发,萌发率与光照时间长短无关(p>0 05);休眠卵保存大约1个月左右萌发率较高;带水低温萌发率较高,干燥低温次之,常温干燥保存最低.     

Discovery of the budding phosphatized globular fossils from the Neoproterozoic Doushantuo Formation at Weng’an, Guizhou Province, China

There is much debate on biological affinities of the phosphatized globular fossils from the Neoproterozoic Doushantuo phosphorites at Weng’an, Guizhou Province. Here we report for the first time the budding structures of some of these globular fossils, which have previously been interpreted as the resting eggs and early cleavage embryos of metazoans. The budding structures are similar to the germinating tubes of the spore and zygote of living algae, suggesting that some globular fossils from the Doushantuo phosphorites bear affinity with algae. The present new information indicated various biological affinity of the phosphatized globular fossils from the Doushantuo phosphorites.     

“变质蛋”带菌情况的研究

对安徽省阜阳市某蛋品加工厂“变质蛋”带菌情况进行分析,为阜阳市食品质量与安全管理提供理论依据.用微生物学方法,从247枚“变质蛋”中共分离出细菌401株,其中包括肠杆菌科191株(47.63%),葡萄球菌属90株(22.44%),假单胞菌属16株(3.99%),枯草杆菌31株(7.73%),巴氏杆菌属9株(2.24%),支气管败血波氏杆菌10株(2.49%),果胶杆菌1株(0.25%),未知菌53株(13.22%).结果显示,“变质蛋”以肠杆菌科细菌占优势,经感观检验,所测“变质蛋”中pH值均较正常蛋为低,在6.0~7.7之间,且pH值越低,蛋变质程度越严重.     

Antibacterial activity in the egg mass of a sea hare

Summary The eggs of a sea hare,Aplysia kurodai, contained antibacterial factors which probably play a role in the defense of eggs against bacterial infection. The active factors were composed of several heat-labile proteins, unrelated to lysozyme, and were produced in the albumen gland.     

青虾的人工育苗试验

选择产自天然水域的抱卵虾作为亲虾进行室外小水泥池人工育苗试验,两口水泥池共32平方米共获0.8～1.2厘米的虾苗30万尾,平均每平方米水面产虾苗9300尾。     

On the natural history of the South American pepper frog,Leptodactylus labyrinthicus (Spix, 1824) (Anura: Leptodactylidae)

Some species of Leptodactylus of the L. pentadactylus group lay their eggs outside water but the tadpoles need to reach water to complete the larval phase; other species complete development in terrestrial nests. Here we present details of the reproduction of L. labyrinthicus in south‐eastern Brazil. The proportion of tadpoles and trophic eggs in aged egg clutches was determined, as well as the growth of the tadpoles while in the nest. The gut contents of tadpoles that were in egg clutches of frogs were analysed. Adult males did not differ from females in size and had hypertrophied forearms and an enlarged spine on the thumb. Reproduction was initiated with the first rains of August/September and extended to mid‐January. Calling and spawning occurred at permanent or temporary water bodies. The foam nests were built in excavated basins outside of, but close to the water. The male determined the place of the basin construction; after amplexus, the female completed the excavation. The amplexus was axillary. One female spent the day after spawning in the foam. The eggs were pale grey, the yolk averaging 2.3?mm in diameter. The mean number of eggs was 2101 per egg clutch. The number of tadpoles in individual nests varied between 0.05% and 11.40% in relation to the total laid eggs. The tadpoles entered water when rains flooded the basin. The tadpoles grew to 12 times the weight of an individual egg while in the nest; no nesting tadpole was beyond stage 25. The longest time we followed tadpoles in a nest was 25 days. Tadpoles were found preying upon eggs of three other frog species and upon conspecific eggs. Males fought by grasping each other in a belly‐to‐belly position; the powerful arms and the thumb spines represent weapons. Even though males can reach maturity in the season following birth, small size would prevent them from establishing their own territory. All the species of the L. pentadactylus group may build their foam nests within excavated basins. The basins may protect the eggs and embryos from cannibalistic tadpoles and may have an anti‐desiccation effect. In order to produce trophic eggs, the female may delay laying additional unfertilized eggs until after the male has abandoned the foam nest. Anuran eggs represent an important food item for tadpoles after they leave the nest.     

鸡蛋浸泡贮存后的营养成分初报

营养价值是鸡蛋贮存保鲜技术研究和使用的基础。本文使用我们研制的ＡＡＮ 浸泡液对延安附近罗斯鸡产１ｄ、３ｄ 、７ｄ 蛋进行浸泡贮存５ 个月和１０ 个月，贮后营养成分除维生素与贮前相差十分显著（Ｐ＜ ０－０１） 外，其余均相差不大，Ｐ＞ ０－０５ 。且发现，相同蛋龄蛋贮存１０ 个月营养成分与贮前鲜蛋相差大于贮存５ 个月蛋，相同贮存期７ｄ 蛋龄蛋营养成分与贮前鲜蛋相差明显大于１ｄ 和３ｄ 蛋龄蛋。     

有效微注射和移植受精卵建立转基因鼠

试验研究了转基因小鼠建立中的受精卵显微注射和移植，对获得受精卵、有效注射及移植易出现的问题和解决方法进行了讨论，对注射后的受精卵的移植加以改进，建立了人Ｇ－ＣＳＦ转基因小鼠模型．     

蝗虫卵饲育虹鳟稚鱼初探

本文试验了用蝗卵饲育虹鳟稚鱼,结果表明,虹鳟稚鱼生长快,疾病少,管理方便,成活率高．并阐述了虹鳟稚鱼蝗卵饲育的有关技术资料．     

鸡蛋皮蛋微波杀菌工艺优化研究

研究鸡蛋皮蛋微波杀菌工艺特性和杀菌效果,包括杀菌功率、杀菌时间和装载质量对产品感官品质的影响,对这三个主要因素进行正交试验,筛选微波杀菌最佳工艺条件。所选出的最佳工艺条件为:微波功率700 W(此时杀菌温度为85℃)、杀菌时间18 min、装载质量0.9 kg。按此生产的产品菌落总数(cfu/g)≤100,大肠菌群(MPN/100g)≤30、致病菌为零,杀菌后蛋黄、蛋白均未出现变干和变硬现象,保质期180 d。