深圳湾沿岩池养黄鳍鲷的繁殖生物学

根据１９９４～１９９６年在深圳湾沿岸养殖场采集的黄鳍鲷的调查资料，就该鱼的繁殖生物学的一些问题作了探讨。     

深圳湾沿岸池养黄鳍鲷的繁殖生物学

根据1994～1996年在深圳湾沿岸养殖场采集的黄鳍鲷的调查资料,就该鱼的繁殖生物学的一些问题作了探讨.     

产胶蜂产胶量、产蜜量的测试

蜂胶是蜜蜂从胶源植物新生枝腋芽或花蕾处采集的树脂类物质,掺入其上颚腺及蜡腺分泌物,经蜜蜂反复加工而成的胶状物质,主要应用在医药、食品、化妆品等领域.在市场上越来越走俏,呈供不应求之势,价格也逐年上涨,而全国只有一部分养蜂户生产蜂胶,且产量不高,满足不了市场需求.本研究对产胶蜂种的产胶量、产蜜量、越冬性能等进行了研究.     

宜州市经济鱼类的调查及渔业现状分析

通过对宜州市经济鱼类种类的调查统计，分析宜州渔业的发展现状并提出相应的发展对策。     

豫东池塘混养罗非鱼的研究

本文就罗非鱼在豫东池塘混养的可能性、生长期、成活率等进行了探讨，并对混养方法及管理要点作了阐述，旨在推动罗非鱼在河南的养殖。     

龙须菜池塘养殖及其对氮磷去除效果的研究

【目的】研究龙须菜(Gracilaria lemaneiformis)在海参养殖池塘中的生长特性及其对水体中氨氮和活性磷的去除作用。【方法】2014年6~8月,在山东乳山海参养殖池塘试验养殖龙须菜,设置不同养殖深度和养殖方法,共养殖80d。【结果】龙须菜最大增重从0.7kg到6.1kg,增长8.5倍,其SGR可达5.5%;水体氨氮平均下降22.7%,活性磷下降21.4%。【结论】龙须菜可以在适合的池塘中养殖,并且能有效去除水体中的氨氮和活性磷,是有效的近海生境修复海藻。     

三疣梭子蟹养殖池塘水体中异养细菌菌群特征的研究

对三疣梭子蟹养殖池塘水体异养细菌的数量和菌群组成进行了调查分析.分离得到240株细菌,根据其菌落和菌体形态特征,分为15个类群和31个亚群.结果表明:自然水体进入养殖池塘后,其优势菌菌群和亚群都发生了显著改变,这些改变可能与池塘高有机质的分解和蟹病的发生有密切关系.     

中华秋沙鸭(Mergus squamatus)在江西省的越冬分布及种群数量调查

2006年12月,对江西省境内三龙镇西河段、浮梁县昌江段、婺源县乐安江段、弋阳县清湖乡信江段、修水县修水段、吉安县永和镇赣江段和万安县窑头镇赣江段等14个河段和地点进行了中华秋沙鸭越冬分布地和数量调查,共记录到中华秋沙鸭82只,31雄51雌或幼.其中弋阳和婺源为有记载分布地;浮梁县昌江和修水县修水段为首次发现,且数量较大,分别达到22和23只.本次调查发现,中华秋沙鸭越冬栖息地环境特征具有明显共性,多选择生活在水质好、深度较浅、水流较急、河中央有砾石兀立或砾石漫滩的宽阔河流中.此外,调查结果也显示,中华秋沙鸭在江西省适合栖息的江段和越冬种群数量均应远多于此次的调查,江西省是中华秋沙鸭在我国主要的越冬分布区之一.     

Obtaining the best possible predictions of habitat selection for wintering Great Bustards in Cangzhou,Hebei Province with rapid machine learning analysis

Great Bustards （Otis tarda dybowskii） are one of the world＇s heaviest flying birds, occupying grassland hab- itats in Eastern Asia. Our study is located at the most eastern Chinese wintering site in Cangzhou, Hebei Province, where approximately 100 individuals are concentrated in a small area （17.53 km2）. Solid information is still lacking about the wintering areas for this subspecies in its eastern range and specifically for China. The study area consists of intensely used farmland in proximity to humans and is lacking con- servation areas and wild, open fields. Here, we present our results from two years of field data collection on habitat selection. We choose a machine learning model approach based on a rapid assessment methodology for the winter habitat of the Great Bustard. It is based on a spatial analysis of the best available environmental data, which were col- lected relatively quickly. These relatively new methods in ecology are based on an ensemble of decision trees and include algorithms such as TreeNet, Random Forest and CART used in parallel. In this study, we collected bustard droppings （presence only） from 48 locations between December 2011 and January 2012 and used the sites as training data. Droppings from 23 locations were collected in November 2012, and those sites were used as test data. We used eight environmental variables as predictor layers for the response variable of bustard presence/availability. We employed a Geographic Information System （ArcGIS 10.1and Geospatial Modelling Environment） and Google Earth. Compared with the other three models, we found that pre- dictions from Random Forest obtained a significant differ- ence between presence and absence. According to this model, the three most important factors for wintering Great Bustards are distance to residential area, distance to water pools, and farmland area. Our model shows that wintering Great Bustards prefer locations that are over 400 m away from residential areas, within 900 m of water pools and on areas o     

枯草芽孢杆菌制剂对罗氏沼虾养殖池塘水质的影响

采用枯草芽孢杆菌制剂,对养殖中后期的罗氏沼虾池塘进行了改善水质的试验。通过测定水体的溶解氧、pH、化学需氧量、氨氮和亚硝酸态氮等水质指标,来评价池塘的水质变化。结果表明:枯草芽孢杆菌制剂对于水体中溶解氧含量和pH值的影响不明显(P>0.05),但能显著降低水体的化学需氧量(P<0.05);使用枯草芽孢杆菌制剂后,氨氮的最大降解率为59.61%,亚硝酸态氮的最大降解率为86.70%,说明它有明显降低水体氨氮和亚硝酸态氮含量的作用(P<0.05)。