浙江安吉刚竹属2个新变型

2006年6月12日，由国家林业局科技司主持在南京组织有关专家对由南京林业大学主持完成的“袋泡竹炭净化和营养保健剂”成果进行了鉴定。该项研究了竹炭的制备工艺，以及竹炭表面的物理化学性质对有害物质的去除、矿物质和微量元素释放的影响。研制了由竹炭、活性炭和麦饭石优化复合的新型袋泡竹炭净化和营养保健剂。     

三种赤眼蜂对灰白蚕蛾的卵龄选择

灰白蚕蛾Ocinara varia.是近年来华南地区为害较严重的园林害虫,为筛选有效防治灰白蚕蛾的赤眼蜂种,在室内条件下比较了短管赤眼蜂Trichogramma pretiosum、松毛虫赤眼蜂T.dendroli-mi和暗黑赤眼蜂T.euproctidis对不同卵龄灰白蚕蛾卵的寄生能力和适应能力.结果显示,随寄主卵龄的增加松毛虫赤眼蜂和暗黑赤眼蜂寄生卵数均呈下降趋势,且都在灰白蚕蛾卵龄为6h的卵上寄生卵数最多,分别为15.90粒/雌和12.20粒/雌;而短管赤眼蜂的寄生卵数随寄主卵龄的增加呈先上升后下降趋势,在卵龄为24 h时达最高,为8.25粒/雌;在各卵龄段,松毛虫赤眼蜂的寄生卵数均比其它2种蜂多;当寄主卵龄超过72 h时,3种赤眼蜂的寄生卵数均显著下降.3种赤眼蜂在寄生卵龄为6h的寄生卵上羽化率最高,当卵龄超过72 h时,其羽化率均显著下降.松毛虫赤眼蜂和暗黑赤眼蜂对6h卵龄的灰白蚕蛾卵致死能力最强,而短管赤眼蜂对24 h卵龄的灰白蚕蛾卵致死能力最强.综合分析表明,松毛虫赤眼蜂在灰白蚕蛾卵上的寄生能力和适应能力最好,是灰白蚕蛾的有效天敌.     

水草密度对中华小长臂虾养殖池塘水质和生长的影响

为探索养殖池塘水草覆盖面积对养殖水质和对中华小长臂虾生长性能的影响,设伊乐藻密度为10％、30％、50％(A、B、C)3组试验,每666.7m2放养平均尾重0.01 g的虾苗50万尾.每5天测定一次水化指标,试验结束后测量虾的生长指标及饲料系数.结果 表明,水温在20天后A＞B＞C;溶氧在15天后B＞A,C组在25～4...     

Early weaning of cuttlefish (Sepia officinalis,L.) with frozen grass shrimp (Palaemonetes varians) from the first day after hatching

The suitability of early weaning cuttlefish using frozen grass shrimp, and its effects on growth and mortality was determined in a 50‐day experiment. Three food groups were used. One group (C) was fed with live prey until 25th DAH and weaned with frozen prey until the end of the experiment. In the other two groups, weaning started at the fifth DAH (W5) and first DAH (W1), also with frozen diet. Significant differences were found between C and the remaining treatments (P < 0.05) for mean wet weight (MWW), instantaneous growth rate (IGR), biomass (B) and mortality at the 25th and the 50th DAH. Despite the lower growth (~1/3 of the achieved with live food) and higher mortality (3% obtained by C versus 23% in the W1 and W5 groups), C cuttlefish presented a similar weight gain tendency to W1 and W5 groups after weaning. This is the first record of early acceptance (at the first DAH) of frozen food by cuttlefish hatchlings. These differences could be related with digestive enzymes of cuttlefish and prey, changes in nutritional composition and amount of captured prey, etc. Future research should also address the effects of this early weaning on cuttlefish life cycle.     

Effects of temperature, density and early weaning on the survival and growth of Atlantic ditch shrimp Palaemonetes varians larvae

This investigation examined the effects of temperature, density and early weaning on the survival and growth of Palaemonetes varians larvae. Survival of larvae raised at 17.5 °C was not significantly different (average + standard deviation) (94 ± 5%) from the survival of those raised at 19.5 °C (95 ± 5%) and at 21.5 °C (94 ± 4%). However, the duration of the larval stage was significantly longer for shrimp reared at 17.5 °C (17.3 ± 0.8 days) compared with shrimp reared at 19.5 °C (14.3 ± 0.7 days) and at 21.5 °C (11.3 ± 0.6 days). No significant differences ( P >0.05) were found in the survival rate, final weight and length of larvae reared at the densities of 5, 10, 20 and 50 larvae L⁻¹. The survival of P. varians larvae fed solely on Artemia was significantly higher ( P <0.05) than larvae weaned with an artificial practical diet from Zoea II stage (94 ± 4% and 82 ± 1%, respectively, for Artemia and artificial diet-fed larvae), but no significant differences ( P >0.05) were observed in the final larval weight or length between these two treatments. The survival and growth of the larvae fed with the practical diet tested is a promising step ahead in the development of the culture of this species as it eliminates both the need for Artemia throughout all larval stages, and the need for more expensive artificial diets.     

南安板鸭发酵工艺技术研究

利用植物乳杆菌、戊糖片球菌、木糖葡萄球菌和变异微球菌混合发酵生产发酵型南安板鸭。采用正交试验,得到最佳的发酵工艺条件为：植物乳杆菌、戊糖片球菌、木糖葡萄球菌与变异微球菌之间的比例为1∶1∶2∶2,发酵温度为30℃,发酵时间为18 h,接种量为3%。经混合发酵后,氨基酸态氮含量增加,板鸭风味增强,营养价值提高。     

Influence of temperature and size on menthol anaesthesia in Chinese grass shrimp Palaemonetes sinensis (Sollaud, 1911)

Chinese grass shrimp, Palaemonetes sinensis (Sollaud, 1911), is an economically important freshwater shrimp in China and adjacent areas. It is advisable to use anaesthesia in this species for certain handling and shipping operations; however, there have been no investigations into the recommended dosages. Here, the influence of five menthol concentrations (varying from 100 to 500 mg/L) on three different size classes of P. sinensis were examined at 8, 12, 16, 20, 24 and 28°C. Induction and recovery times for each shrimp were recorded, and effects of temperature, size and menthol dose on induction and recovery times were observed. Results showed that menthol dose, water temperature and shrimp size significantly influence anaesthesia in P. sinensis. Induction time decreased linearly with increasing water temperature and concentration of menthol, and increased with body weight. However, recovery times lengthened with concentration and temperature, and became shorter with body weight. Average body weight of the shrimps generally decreased after anaesthesia. Mortality of shrimps was correlated with temperature, dose and size. These results suggest that menthol is an effective rapid anaesthetic for P. sinensis, but there may be some disadvantages, including slow recovery and possible mortality for small shrimps and at higher temperatures and dosages.