不同开口饵料对克氏原螯虾幼虾发育及消化酶活性的影响

实验采用丰年虫无节幼体、草鱼鱼糜、水蚯蚓、1号人工配合饲料和2号人工配合饲料为克氏原螯虾的开口饵料,观察幼虾存活率和生长情况。经过40d的培育,对幼虾的胃蛋白酶、胰蛋白酶、淀粉酶和脂肪酶的活力进行测定。结果表明：投喂丰年虫无节幼体的实验组幼虾存活率最高,为75,增重率和增长率也最大,分别为4746.00和171.00。幼虾的胃蛋白酶活性与投喂的饵料密切相关,投喂丰年虫无节幼体组幼虾的胃蛋白酶和胰蛋白酶活性分别为2.18U/mgprot和0.96U/mgprot,极显著高于投喂草鱼鱼糜实验组。实验的5种开口饵料中,丰年虫无节幼体是克氏原螯虾幼虾的最佳开口饵料。摄食丰年虫无节幼体可能提高了主要消化酶的活性,从而促进了克氏原螯虾幼体的生长。     

水位变化对蛤蟆通水库浮游植物种群动态影响的研究

1991－1993年蛤蟆通水库水位变化对浮游植物种群的动态影响研究结果表明：1）浮游植种属数随水位下降而减少；2）浮游植物生物量随水位下降而升高，其关系式为y＝299．46－3．37x,r=-0.998;3)浮游植物多样性指数随水位降低而变小，并且与水位呈明显的相关性（r＝0．999，r＝0．983）。     

Effect of l‐ascorbyl‐2‐polyphosphate supplementation on growth performance,body composition,antioxidative capacity and salinity stress tolerance of juvenile Pacific white shrimp,Litopenaeus vannamei

An 8‐week feeding trial was conducted to evaluate the effects of ascorbic acid (AsA), in the form of l ‐ascorbyl‐2‐polyphosphate (LAPP) on growth performance, body composition, antioxidative capacity and salinity stress tolerance of juvenile Pacific white shrimp, Litopenaeus vannamei. Five practical diets (46% crude protein and 7.6% lipid) supplemented with graded levels of AsA (14.64, 48.55, 84.98, 308.36 and 639.27 mg kg^?1 diet) were fed to five replicate groups of L. vannamei (mean initial wet weight 0.57 g). No significant differences were found on growth performance among all treatments. However, whole body lipid content significantly decreased with dietary AsA levels increasing. Activities of total antioxidant capacity, glutathione reductase and glutathione peroxidase were significantly affected by dietary AsA levels. Shrimp fed LAPP‐free diet had higher malondialdehyde content than those fed the diets supplemented with LAPP. Dietary AsA levels higher than 308.36 mg kg^?1 diet increased the survival of shrimps after 1, 2 and 3 h of acute salinity change. Broken‐line regression analysis on survival after 3 h of salinity stress and second‐degree polynomial regression analysis on glutathione reductase data indicated that the optimal dietary AsA requirement of L. vannamei was estimated to be 306.39, 319.75 mg kg^?1 diet respectively.     

白斑综合证病毒胶体金免疫层析试剂板的研制

将胶体金免疫层析技术应用于对虾白斑综合征的诊断,研制了一种检测对虾中白斑综合征病毒的胶体金免疫层析试剂板.将胶体金标记的抗白斑综合征病毒单克隆抗体包被在金标垫上,将抗白斑综合征病毒多克隆抗体和羊抗鼠IgG分别包被在硝酸纤维素膜的检测线和质控线上.通过双抗体夹心法检测样品中自斑综合征病毒含量.结果表明,该试剂板对白斑综合征病毒的最低检出限为1.0 mg/kg,特异性好,稳定性高,整个检测所需时间为8～10 min,适合现场快速检测.     

青藏高原景观多样性和生物遗传多样性

青藏高原独特的景观和生物资源遗传多样性是藏民族物质文明的戢体和精神文明的传承者。本文综述了青藏高原的成因、生物资源遗传多样性和景观多样性。     

鱼类耗氧率测试装置的设计

本文论述了鱼类耗氧率测试装置的结构设计,讨论了平均体质量（156±3.36）g匙吻鲟（Polyodon spathula）幼鱼耗氧率与窒息点的测试方法。在结构设计中,尺寸参数的选择确保了鱼类耗氧率、窒息点测试过程中流入呼吸室的水流均匀,水样采样准确;方便了测试过程中对鱼类行为生物学的观察,呼吸室中没有空气气泡干涉,提高了测试数据的准确性。实测结果表明,匙吻鲟幼鱼耗氧率的最高值为（0.528±0.035）mg.g-1.h-1,最低值为（0.197±0.028）mg.g-1.h-1,窒息点为3.468 mg.L-1。     

象山港桐照滩涂小型底栖动物丰度和生物量的研究

调查结果表明,象山港桐照滩涂小型底栖动物有11个类群,线虫在丰度上占绝对优势(93%),其次是涡虫、桡足类等.按生物量统计,线虫占53%,其次是多毛类(18%).小型底栖动物的年平均丰度为4168.66个/10 cm2,年平均生物量1828.39 μg /10 cm2.小型底栖动物在丰度和生物量上出现了明显的季节变化,其最高值分别出现在秋季和冬季.并且还出现了明显的垂直分布,超过60%的小型底栖动物分布在(0～2)cm层段,随着深度的增加数量逐渐减少.     

Effects of dietary live or heat‐inactivated autochthonous Bacillus pumilus SE5 on growth performance,immune responses and immune gene expression in grouper Epinephelus coioides

To evaluate the possible dietary application of live and heat‐inactivated probiotic Bacillus pumilus SE5 in grouper Epinephelus coioides, juveniles (14.6 ± 0.2 g) were fed either a basal control diet (without probiotic) or the basal diet supplemented with 1.0 × 10⁸ CFU g^?1 live (T1) and heat‐inactivated B. pumilus SE5 (T2). The heat‐inactivated probiotic significantly improved the final weight, weight gain (WG) and specific growth rate (SGR) at day 60 and significantly decreased the feed conversion ratio (FCR) at day 30 and 60, while the viable probiotic significantly decreased the FCR at day 60 (P < 0.05). Phagocytic activity, serum complement C3 and IgM levels as well as SOD activity elevated significantly in fish fed the heat‐inactivated probiotic for 60 days (P < 0.05). Furthermore, the heat‐inactivated probiotic remarkably up‐regulated expression of TLR2 and pro‐inflammatory cytokines (IL‐8 and IL‐1β) in head kidney (P < 0.05), but the viable probiotic failed to do so. These results indicated that heat‐inactivated B. pumilus SE5 can effectively improve the growth performance and immune responses of E. coioides.     

鳜鱼和奥利亚罗非血乳酸脱氢酶酶谱的比较

哺乳类动物各种组织和器官的乳酸脱氢酶(LDH)同工酶较稳定,酶带分布非常有规律,同源组织的LDH同工酶酶谱通常相似和稳定。鱼类LDH同工酶复杂得多,有三分之二品种中,其LDH同工酶类似哺乳类动物的酶谱;但在其余三分之一种类中,两个亚基随机结合受到限制,出现了不规则酶谱,有的只有2—3条酶带,有的超过5条酶带。即使具有5条酶带的鱼中,其骨骼肌和心肌LDH在电泳酶谱上迁移快慢正好与哺乳类动物相反。此外鱼类C基因产物并不特定在某一组织或器官中,一些鱼的     

芦笋全雄新品种'WF-8'

芦笋‘WF28’是利用芦笋雄性系两性株选育出的全雄一代杂种, 生育期为245 d, 平均茎高220 cm左右。白笋色泽洁白, 笋条直, 粗细均匀, 质地细嫩, 包头紧密, 无空心, 单支笋质量51 g左右,一级笋率92.2%。平均产量为15 000 kg·hm^-2。白笋铁含量为0.043 mg·g^-1。适宜白笋、绿笋栽培。