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11.
以淡水鱼加工副产物为原料,经过不同条件的储藏后得到不同新鲜度的副产物,分别接种米曲霉后置35℃发酵30d制备鱼露。对副产物和鱼露的理化特性进行评价,结果表明,副产物经储藏后品质发生不同程度的变化:常温储藏4h后,副产物的pH值、挥发性盐基氮(TVB-N)、硫代巴比妥酸及菌落总数均比冰藏和冻藏副产物的相关指标高,而冰藏8h副产物的相关指标则高于冰藏4h副产物的指标;以常温储藏4h的副产物为原料发酵所得的鱼露,其氨基酸态氮、总可溶性氮含量最高,然而其TVB-N和三甲胺含量也最高;以冰藏4h的副产物为原料发酵所得鱼露的生物胺总量和组胺含量最高。副产物经常温4h储藏后其理化特性发生了一定改变,但并未对鱼露的整体品质产生显著的不良影响,因此,淡水鱼加工副产物在常温储藏4h以下可以用于速酿鱼露的发酵。 相似文献
12.
4种淡水藻对硝基苯的抗性机制 总被引:1,自引:0,他引:1
选择了4种淡水藻——纤细裸藻、莱因衣藻、舟形藻和聚球藻,通过分析硝基苯对其生长和叶绿素含量的影响,以及藻细胞对硝基苯的降解、积累和抗氧化酶系统的响应,以期了解藻类对硝基苯的抗性机制.结果表明:4种藻的生长和叶绿素a含量对硝基苯的抗性,按抗性大小排列:纤细裸藻〉莱因衣藻〉舟形藻〉聚球藻,4种藻对硝基苯无显著的降解和积累能力,藻细胞对硝基苯的抗性主要依赖抗氧化酶系的防御作用,其中藻细胞的SOD起主要作用,POD起次要作用. 相似文献
13.
《Journal of Natural History》2012,46(1-2):21-33
Habitat modification, pollution, overfishing, poaching, competition from non‐indigenous species, and diseases have led to the extinction in Europe of many populations of indigenous crayfish. Under the rationale that any programme of reintroduction should be preceded by a thorough understanding of habitat requirements of the species of concern, we studied the microhabitat use of an Austropotamobius pallipes population in Tuscany, central Italy. Microhabitat use was assessed for water depth, current velocity, substrate, percentages of boulders, underwater tree roots, and in‐stream vegetation cover. Results show that A. pallipes' habitat use is size‐partitioned. Smaller individuals mostly occupy stream edges in shallow waters with submerged roots, whereas larger individuals use deeper waters, often associated with boulders. Crayfish spatial distribution is restricted mostly to the microhabitats characterised by extensive cover and slow current velocity. The study highlights the importance of habitat heterogeneity and cover elements for the protection of this indigenous species. 相似文献
14.
《Journal of Natural History》2012,46(21-22):1351-1368
ABSTRACTIn Mexico, there are currently two known species of Racekiela: R. ryderii and R. montemflumina. Here we describe a new species from high-altitude streams in central and southern Mexico. Racekiela cresciscrystae sp. nov. presents two morphotypes: thick encrusting with raised ridges or lobose outgrowths at the surface and dark green in colour, or lime-green encrustations. The new species as megascleres presents microspined oxeas from 200 to 300 µm long, some centrotylote, or with malformations. Gemmules are spherical with a tri-layered theca, constituted by radially embedded birotules and pseudobirotules. The birotules have longer shaft than the rotule diameter, which is flat, and some slightly umbonate. Pseudobirotules of typical morphology have strongly or somewhat spined shaft. Spines can be straight or hooked. The species also presents other type of pseudobirotules, which are umbonate and with only small warts, instead of spines. DNA sequences from the nuclear ITS1-5.8-ITS2 region were sequenced from the holotype and a paratype of the new species to determine their phylogenetic relationships with other members of the family Spongillidae. Tree topologies (Bayesian Inference and Maximum Likelihood) were consistent in showing Racekiela creciscrystae sp. nov. as a sister clade of R. montemflumina confirming its allocation in a monophyletic genus Racekiela. A comparison with all the Racekiela species described so far is also included. This paper increases the number of species of freshwater sponges in Mexico, and confirmed that Racekiela is a monophyletic genus with morphological characters very well defined.http://www.zoobank.org/urn:lsid:zoobank.org:pub:3769C54F-23C4-409A-AF02-81F3AA084F7Ahttp://www.zoobank.org/urn:lsid:zoobank.org:act:A512359D-E428-4D04-B08A-E189E3F6F962 相似文献
15.
《Journal of Natural History》2012,46(47-48):2993-3004
ABSTRACTWe describe a new species of freshwater crab, Himalayapotamon robertsianum sp. nov. from Punjab province of Pakistan, based on morphological characters of the carapace and the first gonopod. The new species demarcates the westernmost distribution limit of the genus. Additionally, we analysed partial sequences of the 16S rRNA locus for some species of the genus Himalayapotamon (p-distances, Bayesian phylogenetical inference), indicating that Himalayapotamon separates into an eastern and a western clade. Based on these results, we propose a biogeographical scenario that can explain the occurrence of the genera Himalayapotamon and Potamon within the same river system: we assume an ancestral widespread distribution of Himalayapotamon in the palaeo-Ganges. When drainage rearrangement diverted the western tributaries of the Ganges into the Indus since the latest Miocene, Himalayapotamon diverged into two clades. Consequently, the western clade is now sharing the Indus drainage with Potamon.urn:lsid:zoobank.org:pub:80B52E6C-0120-4669-A6B0-9F0DA5918EE3 相似文献
16.
用ATPase活性测试盒测定了尼罗罗非鱼鳃和肾中Na+-K+-ATPase活性在海、淡中的变化.从淡水到海水中,尼罗罗非鱼鳃和肾Na+-K+-ATPase活性分别增强了1.61倍和1.41倍;把尼罗罗非鱼由淡水直接放入海水,鳃中的Na+-K+-ATPase活性升高较剧烈,在前期(0.5 h)最高,在鱼即将死亡的后期(8 h)次之,在中期(3 h)较低;肾中Na+-K+-ATPase活性升高较缓慢,在前期较小,中期较高,后期最高.除了在淡水中,肾的Na+-K+-ATPase活性高于鳃外,在海水中以及海水的前期、中期和后期中,鳃的Na+-K+-ATPase活性都高于肾,与肾相比,鳃对肾盐协迫更为敏感. 相似文献
17.
6种淡水腹足类足肌蛋白质的比较研究 总被引:2,自引:0,他引:2
以隶属于软体动物门、腹足纲、中腹足目、Jiao蚴科的大沼螺、纹沼螺、长度涵螺、光滑狭口蚴为研究对象,以田螺科的梨形环棱螺、黑螺科方格短沟蜷作为对照,用凝胶电泳方法对上述动物进行了足肌蛋白质的比较研究。结果显示腹足类的足肌蛋白质不但具有种内稳定、种间差异显著的特性,而且电泳谱带的差异程度能够反映出物种的遗传特性和相互的亲缘关系。其中以主要区带的数量、Rm值含量最为明显。通过数值聚类分析后显示,大沼螺、纹沼螺、长角涵螺之间的亲缘关系较近,而光滑狭口螺与上述3个种的亲缘关系较远,其分类地位与梨形环棱螺和方格短沟蜷类似。实验结果与修订后的中腹足目科级分类方案相当吻合。 相似文献
18.
广西森林溪流淡水鱼类区系研究 总被引:1,自引:0,他引:1
李红敬 《信阳师范学院学报(自然科学版)》2002,15(2):199-203
通过调查发现,分布于广西森林溪流中淡水鱼类有92种,分别隶属于5目、16科、63属。鲤形目占64.1%,鲇形目占11.96%,鲈形目占20.65%,合鳃目占1.01%,Jiang形目占2.72%。其中鲤科鱼类占总种数的46.7%。可划分为热带平原、江河平原、中印山区、上第三纪、北方平原5个区系复合体。在不同的海拔高度鱼类分布不同,具有明显的山区特征,广西森林溪流淡水鱼类区系形成与广西自然环境的历史演变有密切关系。 相似文献
19.
A. Viarengo L. Canesi M. Pertica D. R. Livingstone M. Orunesu 《Cellular and molecular life sciences : CMLS》1991,47(5):454-457
Summary The main cellular defence systems against free radical-mediated oxidative stress are significantly reduced in the dige+ive gland of aged (>10 years old) compared to younger (2–4 years old) mussels (Mytilus edulis L.). Moreover, the concentration of lipid peroxidation products (malondialdehyde) is increased in the same age group with respect to younger animals. The obtained data indicate that an impairment of the antioxidant defence systems would render the older animals more susceptible to peroxidative stress, thus supporting the general significance of the free radical theory of aging. 相似文献
20.
Persistent organic pollutants PCNs and PBDEs in sediments from coastal waters of Qingdao,Shandong Peninsula 总被引:4,自引:0,他引:4
YANGYongliang PANJing LIYue YINXiaocai SHILei 《科学通报(英文版)》2004,49(1):98-106
Thirty-one congeners of polychlorinated naphthalenes (PCNs) and 21 congeners of polybrominated diphenylethers(PBDEs)in surface sediments at 5 stations and one mussel sample from Qingdao coastal waters were analyzed. The maximum contents occur at the station near the Haibo River mouth. The total PCNs contents are in the range of 212-1209 pg/g dw, dominated by tri-Cl CN. The total PBDEs contents are in the range of 117-5510 pg/g dw,dominated by tri- to hexa-BrBDEs. The local sources of PCNs are likely from combustion processes such as incinerations and coal burnings. The sources of PBDEs are molecular diffusion from the materials containing them. Except for the area near the river mouth where is affected by the sewage sludges, an important source of PCNs and PBDEs in this area is believed to be the atmospheric deposition. Mussels enrich PCNs and PBDEs relative to the sediments. The total TEQs of PCNs in mussels are lower than the total TEQs of PCBs. 相似文献