The impact of shrimp farming effluent on bacterial communities in mangrove waters, Ceará, Brazil

The effects of shrimp farm effluents on bacterial communities in mangroves have been infrequently reported. Classic and molecular biology methods were used to survey bacterial communities from four mangroves systems. Water temperature, salinity, pH, total heterotrophic bacteria and maximum probable numbers of Vibrio spp. were investigated. Genetic profiles of bacterial communities were also characterized by polymerase chain reaction (PCR) amplification of eubacterial and Vibrio 16S rDNA using denaturing gradient gel electrophoresis (DGGE). Highest heterotrophic counts were registered in the mangrove not directly polluted by shrimp farming. The Enterobacteriaceae and Chryseomonas luteola dominated the heterotrophic isolates. Vibrio spp. pathogenic to humans and shrimps were identified. Eubacterial genetic profiles suggest a shared community structure independent of mangrove system. Vibrio genetic profiles were mangrove specific. Neither microbial counts nor genetic profiling revealed a significant decrease in species richness associated with shrimp farm effluent. The complex nature of mangrove ecosystems and their microbial communities is discussed.     

Juvenile albacore from New Zealand (note)

Juvenile albacore (Thunnus alalunga) caught in the New Zealand region between 1970 and 1972 are about 1 year old. There is some evidence of southward migration of these small fish along the west coast. Small albacore also occur in the North Pacific.     

厦门潘涂虾池及其附近内湾各态氮的季节性变化特征

1996年6月至1997年2月，对厦门市潘涂垦区两口虾池及附近内湾不同形态氮的含量与动态进行调查。结果显示虾池的可溶性有机氮（DON）含量明显高于邻近内湾，颗粒有机氮（PN）多数时间也高于内湾，而邻近内湾可溶性无机氮（DIN）含量则明显比池内的高。虾池中的氮主要以DON形态存在（59．76％），DIN，PN含量较少（9．37％和20．87％）；邻近内湾则是以DIN为主（59．97％），其次为DON（29．55％），PN所占比例最小（10．48％）。吓池与邻近内湾不同形态氮的季节变化也存在一定差异。     

Residues of selected antibiotics in water and mud from shrimp ponds in mangrove areas in Viet Nam

In recent years, antibiotics have been used widely in intensive shrimp culture and this may lead to their contamination of the environment. Surveys on residues of trimethoprim (TMP), sulfamethoxazole (SMX), norfloxacin (NFXC) and oxolinic acid (OXLA) in water and mud in shrimp ponds in mangrove areas were conducted in the north as well as in south of Viet Nam in July and August, 2002. The results show that these antibiotics are found in all samples in both shrimp ponds and surrounding canals. The highest concentrations of TMP, SMX, NFXC and OXLA are 1.04, 2.39, 6.06, and 2.50 ppm in water samples; and 734.61, 820.49, 2615.96, 426.31 ppm (based on wet mud weight), respectively. The comparison of antibiotics residues between study sites and types of shrimp ponds will be discussed in this paper. The results also suggest that antibiotics residues may cause harmful effect on ecosystems in the study sites.     

虾蟹壳提取物氨基葡萄糖美拉德反应及其产物的抗氧化性能研究

首次使用虾蟹壳提取物氨基葡萄糖单一物质制备美拉德反应产物(MRPs)。结果表明,MRPs清除DPPH·能力随反应物浓度、温度和时间的增加而增强;还原能力、清除·OH能力随反应物浓度增加而增强,还原能力随温度、时间增加先增后降,清除·OH能力随温度升高先增后降,随反应时间下降。115℃、0.5mg/ml、90min条件下制备的MRPs清除DPPH·的能力最强为88.73%;65℃、0.6mg/ml、40min的MRPs还原能力最强为A700nm=1.684;65℃、0.6mg/ml、10min的MRPs清除·OH的能力最强为98.72%。MRPs具有很强的抗氧化活性,比Vc和TBHQ抗氧化效果更好,但其抗氧化能力并不完全依赖于产物的褐变程度。氨基葡萄糖MRPs是优良的新型保鲜剂材料。     

卤虫繁殖机制的研究——Ⅰ.卵子发育过程中染色体的变化

本文以卤虫的生殖细胞卵子作为材料进行染色体标本制备,具体研究了卤虫卵子在发育过程中染色体的变化,探讨致使孤雌生殖卤虫染色体自然加倍的可能途径,以及两性生殖卤虫卵子发生受精的具体地点。     

紫外线和温度对虾快速自溶的影响──水产品快速自溶影响因素探讨之一

分别探讨了紫外线和温度对享氏仿对虾和斑节对虾快速自溶的影响。结果表明：紫外线和梯度温度都可提高蛋白质的水解率，紫外照射以３０ｍｉｎ效果最佳。梯度温度比非梯度温度水解速度快。     

A Baseline Study on Benthic Species Distribution in Two Neighbouring Gulfs, With and Without Access to Bottom Trawling

Abstract. An extensive survey of the benthic fauna was carried out at two neighbouring regions of the Aegean Sea, one normally trawled and the other closed to trawlers. Benthic samples were collected from seven areas located away from land-based sources. The faunistic analysis showed that species diversity and abundance was higher in the trawled area compared with the untrawled area, a fact which was attributed to the difference in sediment characteristics between the two areas. A degree of disturbance detected in the trawled area was evidenced by an increase in the number of polychaetes at the expense of other benthic groups and an abundance of some opportunistic species. This could possibly be related to trawling activities. as no other causes of disturbance were found in either area.     

养殖对虾投饵量的研究(Ⅱ)

通过多年生产性试验及测量对虾体长和对虾投饵量的记录,整理出不同体长每万尾对虾投饵量的计算式:Q=1/a+be~(-l)=1/0.6245+42.2379e~(-l)