Study on regional differences in soil-water characteristics and their relevance to aquaculture productivity and fish disease

A total of 45 ponds used for fish polyculture were investigated in three zones of Bangladesh to identify the differences among the zones in respect to aqua-ecology, culture practices, fish productivity and health management. Four hundred and fifty fish from three zones were clinically examined by naked eye and histopathology. Out of total number of fish examined, 45 fish from Dhaka zones were examined for parasites and bacteria in addition to histopathology. Faded and haemorrhagic gill, skin, fin, scale loss and lesions were observed during fish examination. Aeromonas spp. Pseudomonas spp. and Streptococcus spp. were isolated respectively from 56%, 46% and 39% affected fish. Among the five water quality parameters analyzed, the highest average hardness and alkalinity respectively were recorded in Rajshahi (156 ppm and 142 ppm) followed by Dhaka (146 ppm and 132 ppm) and Chittagong (81 ppm and 90 ppm). The highest average pH was recorded in Mymensingh (7.52) followed by Rajshahi (7.13) and Chittagong (7.05). Water holding capacity of soil in Rajshahi zone was poor compared to other zones and farmers were found to be reluctant to fish farming.

灵长类和反刍动物生长激素受体的快速进化

在大部分哺乳动物的进化历程中, 垂体生长激素的进化非常缓慢, 各类群之间没有很大的差别, 但在灵长类和反刍动物的进化过程中却出现了明显的快速进化, 即所谓“插曲式”的进化模式. 我们获 得了4 种灵长类动物的生长激素受体的膜外区序列, 并结合已有的序列数据进行系统的进化分析, 结果 表明, 哺乳动物生长激素受体也经历了一种类似垂体生长激素的所谓“插曲式”的进化模式. 考虑到垂 体生长激素的生物学效应需要通过其受体的介导才能实现, 结合相关性分析的结果, 推测垂体生长激 素受体的这种进化模式可能是与垂体生长激素发生了协同进化的结果.垂体生长

GENETIC VARIATION AMONG SEA BASS POPULATIONS

采用水平淀粉凝胶电泳技术对花鲈群体的遗传结构进行了研究,共检测了中国沿海花鲈146 尾和40 尾日本 东京湾花鲈。其群体的多态位点比例为012667 —015333 ,观测杂合度和预期杂合度分别为010211 —010515 和 010398 —010797。中日花鲈在LDH 3 , GPI21 3 , GPI22 3 基因位点上的等位基因接近完全置换。中国花鲈各群体之 间的根井遗传距离为010004 —010011 ,平均值约为010080 ;而中日花鲈间的根井遗传距离为011870 —011954 ,平均值 为011926。以上结果表明中国花鲈群体间遗传变异很小,中日花鲈间遗传变异远大于中国花鲈群体间的遗传距 离。

Preparation of smoke cured fillets from oil sardine

A method of preparation of smoke cured fillets of oil sardine is described. Various procedural steps like brining, smoking, packaging etc. have been described and the shelf life assessed. Sodium propionate treatment is recommended to enhance storage life; BHA to control rancidity; and thermal treatment to overcome the insect infestation. The product has good consumer appeal.

Fish farm technology. 1 - Brackishwater fish culture based on "aquafeed"

A method has been evolved to enhance the production of natural feed in brackish water fish farms by providing substrates for bio-growth ('aquafeed' production) which is a biomass complex consisting of sedentary and associated organisms of plant and animal species. The seasonal fluctuations of the aquafeed production over different substrates ranged as: 787-1830g/coconut leaf (6m²)/45 days, 16.0-072.9g/glass panel (2x10x10cm²)/30 days, 52-230g/nylon mat (2x25x25cm²)/30 days and 18.6-123.1g/wooden block (6x10x10cm²)/30 days. The average dry weight composition of the major components of aquafeed obtained in the present study was sand-silt-clay 40%, protein 22%, carbohydrate (water soluble) 1.8% and fat 3.35% (water content 85%). Mugil cephalus of 1.85 cm reared in a 0.01ha pond and fed on aquafeed attained a size of 23 cm length and 146.73g weight during one year. Survival rate was 54% at a density of 1000/ha. Salinity and temperature of the pond during the culture period ranged between 1.4 and 32.8‰ and 28.1 and 36.5°C respectively.

Correlation of cell numbers with catalase activities of pure strains of bacteria

An attempt was made to correlate the catalase production with the actual number of aerobic bacterial cells generating the enzyme: bacteria were obtained from the surface of marine fish. A linear correlation was found between the log of catalase activity and log of bacterial count in single culture.

Molecular genetic basis for the rhino mouse from Chinese KM subcolony

Both the rhino mouse and hairless mouse resulted from hairless gene mutation, but they show different phenotypes of skin physiology. The rhino mouse has more similar histological characters to human papular alopecia. Therefore rhino mouse is a good experimental animal model for human papular alopecia. This study reports a hairless mouse named rhino KIZ, arose from KM colony in Kunming Institue of Zoology, by systematic studies on morphology, skin histopathology, gene sequence, pedigree and protein domain analysis. The results demonstrate that a C-to-T transition in exon 11 of hr gene (The mutant gene has been applied for a Chinese patent (patent No. 03135280)) results in the rhino KIZ. The rhino KIZ with clear genetic mechanism will be a useful animal model.

High temperature processing of fish sausage 1. - An improved technique

An improved technique for the preparation of fish sausage (Nemipterus japonicus) over the conventional method (90°degree C for 1 h) has been evolved by processing at a temperature of 115.6°degree C (4.5 kg) for 20 min. The overall quality characteristics of fish sausage, particularly its colour, texture and appearance remained unchanged and the product was in good condition up to 9 days at ambient temperature in contrast to the shelf life of 3 days by conventional method. The design of the equipment used for the processing of fish sausage and the method of operation are described. The keeping quality of the product from an organoleptic stand point was also studied

麂属动物陈旧皮张标本的DNA提取及PCR扩增

用改进的方法从保存于本单位标本中提取DNA, 所得DNA片段的分子量从100bp到1kb以上。利用线粒体DNA细胞色素b通用引物和PCR技术。从小麂、印度麂、贡山麂、费氏麂、黑麂DNA中扩增出307bp的 细胞色素b特异片段(加上两端引物后长度为364bp)。用28种限制性内切酶对 新鲜血样和从陈旧皮张标本中所得扩增片段进行酶切分析, 发现只有4个酶(DraⅠ、xbaⅠ、HaeⅢ、HpaⅡ)在这个片段上有切点, 其中HaeⅢ和HapⅡ的识别位点在各种麂中有所不同。 图3参10

Levels of cadmium in seafood products

The concentrations of total cadmium were determined in 448 samples of processed fishery products comprising crustaceans, molluscs, marine fish and brackish water fish. Shrimp product, the major export item, contained on average 0.122 ppm cadmium and 20% of crustaceans analysed did not contain cadmium on detectable level. Average content of cadmium in 68 marine fish of 9 species was 0.153 ppm and 35% of the samples did not contain the element. Of the total number of crustaceans analysed only 2% showed a level > 0.5 ppm. All the 174 samples of molluscan products, except 3 canned oysters, showed cadmium concentration far below the limit allowed. The average cadmium content in molluscan products was 0.552 ppm.

懒猴能量需求的研究

三组成年懒猴(Nycticebus coucang bengalensis)日均摄入量能值分别为210.19kJ/kG, 177.222kJ/kG和161.608kJ/kG; 日均消化能分别为191.89kJ/kG, 155.131kJ/kG 和146.783kJ/kG。据统计学方差及t测验分析表明:I—Ⅱ组之间和I—Ⅲ之间的日 均摄食量能值及日均消化能均有显著性差异。实验结果表 明: I组所饲喂的配 合饲料的组成优于Ⅱ、Ⅲ组并可做为懒猴 的长期用配方。表4参8

黑长臂猿的分布、现状与保护

黑长臂猿(H y lobates concolor) 是现生11 种长臂猿中其系统地位最低的灵长类。历史时期 长臂猿曾广泛分布在我国南部的大部省区。自公元4 世纪以来, 它们的分布发生了很大变化。分 布区从北到南, 从东到西急剧缩小, 现黑长臂猿缩小到只在海南岛、云南南部和越南北部, 已 分化为6 个亚种。分布于我国的5 亚种中, 海南亚种(H. c. hainanus) 现今仅20 余只, 是最 濒危的一个亚种; . 北部湾亚种(H. c. nasu tus) 50 年代曾在广西西南部发现, 60- 70 年代已绝 迹; 指名亚种(H. c. concolor) 主要分布于越南北部、滇南和滇中哀牢山。滇南约有100 余只, 滇中哀牢山可能有40- 60 群, 180- 240 只; 景东亚种(H. c. j ing d ong ensis) 为滇中无量山的 特有亚种, 现有100- 116 群, 430- 500 只; 滇西亚种(H. c. f u rvog aster) , 只分布在滇西南的 沧源、镇康、云县和耿马等地, 约有26- 42 群, 100- 150 只。现今, 黑长臂猿的分布区已不足 1 000Km 2, 总数量约1 000 只, 为高度濒危的灵长类动物。造成黑长臂猿濒危的主要原因是: 热 带和南亚热带原始森林的被破坏和缩小、人类活动的干扰使生境破碎和恶化、过度猎捕和长臂 猿自身的生物学弱点。目前, 中国的黑长臂猿已在9 个自然保护区中得到保护。

三黄果蝇(Drosophila trilutea)近黄果蝇(D. paralutea)的有丝分裂中期染色体

用产于日本的D. paralutea和产于昆明的D. trilutea三龄幼虫的脑神经节作染色体制片,进行C-带染色观察。其正常染色体与亚组种D. takahashil的染色体十分相似,染色体数均为2n=8。发现在所有的分裂细胞中几乎都包含1对微小染色体。图4参1