首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
    

Seasonal influx of suspended sediments to lakes is common in many aquatic systems, particularly during periods of high flow. Suspended particles not only affect visibility and net primary productivity, as light penetration is reduced, but may also affect the ability of herbivorous zooplankton to locate and ingest food. In Swan Lake, an oligotrophic lake in northwestern Montana, the dose association between zooplankton population development and seasonal maxima in turbidity levels suggests that the community present during peak turbidity is minimally impacted by suspended sediments. This report presents the results of laboratory investigations into the effect of suspended sediments on feeding by the copepod Diaptomus ashlandii, the dominant zoo‐plankter in Swan Lake. Ingestion rate for copepods feeding on 32P labeled algae was significantly reduced in the presence of suspended particles at all turbidity levels tested (5 to 200 NTU's) compared to ingestion rate in the absence of suspended particles (0 NTU's).  相似文献   

2.
H. C. Lai 《Hydrobiologia》1977,54(1):17-21
Seasonal changes in cephalothorax length of Diaptomus oregonensis have been suggested as a means to segregate its life cycle. Problems associated with this technique are also discussed.  相似文献   

3.
4.
  • 1 A series of field and laboratory experiments was performed to test the possible influence of food limitation on UVR tolerance in the calanoid copepod Diaptomusminutus.
  • 2 Food‐limited animals incubated at 0.5 m in a clear‐water lake for over three days showed no evidence for increased mortality compared to food‐replete animals when exposed to UVR.
  • 3 Animals exposed to artificial UVR in the laboratory showed high mortality. There was no evidence that feeding improved UVR tolerance.
  • 4 The results of these experiments show that UVR tolerance is not affected by a short‐term lack of energy or a lack of essential nutrients. However, effects of non‐nutritive dietary components such as carotenoids and mycosporine‐like amino acids cannot be excluded.
  相似文献   

5.
对秀丽洞庭鳜作了较详细的描述,在骨骼学特征和变异范围方面作了较多的补充。指出秀丽洞庭级和下湾铺洞庭鳜在背鳍前骨式、林的形状和尾鳍前短鳍条数目等特征存在差异。补充了洞庭鳜的属征,并认为始新世化石低等鲈形目鱼类中北半球的洞庭鳜、Amphiperca、Priscacara之间的关系比它们和南半球的Percichthys的关系更接近。  相似文献   

6.
本文根据产自四川的模式标本及产自湖北的标本,对绿角星天牛Anoplophora viriantennatus WangJiang,1998进行了重新描述,其雌性为首次报道,该种也是首次记载分布于湖北,并提供了雌、雄成虫及生殖器照片。  相似文献   

7.
对华北落叶松鞘蛾和兴安落叶松鞘蛾的形态特征进行了研究,与容易混淆的欧洲落叶松鞘蛾进行了比较。更正了兴安落叶松鞘蛾的学名,肯定了华北落叶松鞘蛾的分类学地位,并进行了重新描述。文中提供了以上3种落叶松鞘蛾的成虫、雌雄外生殖器等特征图,给出了它们的区别要点。  相似文献   

8.
9.
The achilid genus Rhotala is taxonomically revised based on specimens from China. Four species are recognized in this paper as valid: R. vittata Matsumura, 1914; R. dimidiata Jacobi, 1944; R. fanjingshana Chen et Yang, 2008; and one new species: R. jiangxiensis sp. nov. (southern China: Jiangxi). Male genitalia of these species are described and illustrated. In addition, hind tibia, forewings and hindwings are illustrated for the male of R. jiangxiensis sp. nov. A diagnosis of the genus is redefined. A key to the species of Rhotala in China is presented.  相似文献   

10.
    
  相似文献   

11.
    
A new species of the orchid genus Myoxanthus, M. oliviae, is described based on Peruvian material. The novelty resembles M. serripetalus from which it differs by the 7–8‐veined lateral sepals (versus 6‐ or 9‐veined), the petals contracted below the apex and expanded again into a sagittate apex (versus apex caudate) and entire lip middle lobe (versus fimbriate). The flowers of M. oliviae are pale brownish‐purple, internally intensively suffused with yellow, dark‐purple spotted. The new species grows among rocks at the elevation of 2700–3100 m a.s.l. A key to Peruvian Myoxanthus representatives is provided.  相似文献   

12.
    
Didymodon incurvus J. A. Jiménez & M. J. Cano, is described and illustrated as a new species based on specimens collected from the Puno department in southern Peru. The new taxon is distinguished from others species of the genus by its oblong-lanceolate and appressed leaves when dry, incurved margins above midleaf, and the presence of a bulging ventral costal pad of cells. A key to species of Didymodon in Peru is provided. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 156 , 221–226.  相似文献   

13.
Cryptamorpha sculptifrons Reitter, 1889 is redescribed and a lectotype and paralectotype are designated. The mature larva of C. sculptifrons is described. It is hypothesized that a variety described by Grouvelle (1908), C. sculptifrons var. punctifrons from India, might not be conspecific with Japanese C. sculptifrons. It is also suggested that larvae of Cryptamorpha can be distinguished from larvae of the tribe Brontini by the relatively thick antennae and the 3rd antennomere which is less than 3/4 of the length of the 2nd.  相似文献   

14.
对近来记述的古北区东部地区的毛地蜂属Panurginus Nylander全部14个种作了补充研究。中国对该属的研究较少,仅知2种:黑足毛地蜂Panurginus nigripes Morawitz 和黄跗毛地蜂Panurginus flavotarsus ? Wu。黑毛地蜂Panurginus niger Nylander为该属的模式种,分布于俄罗斯和蒙古,本文报道该种为中国新记录种。目前,中国已知该属3种,分属于2个组即niger-group和herzi-group。文中提供了中国已知种类检索表。  相似文献   

15.
    

The female of Austrosimulium (Austrosimulium) dumbletoni n.sp. is described and compared with other New Zealand species in the subgenus. Females were captured while they were biting caged Fiordland crested penguins, Eudyptes p. pachyrhynchus. They are vectors of the blood parasite Leucocytozoori tawaki.  相似文献   

16.
    
There are many species of Nematomorpha which are deficiently described and therefore pose doubts about their actual taxonomic position. This is the case with Spinochordodes tellinii (Camerano, 1888), which was transferred to four different genera and has been recently considered as species incertae sedis. A female of Spinochordodes tellinii is redescribed in this work under light microscopy and Scanning Electron Microscopy. Cuticle details, shapes and areolar distribution and the features as well as the location of spiniform structures are analysed. The systematic position is discussed.https://doi.org/10.1051/parasite/200209171  相似文献   

17.
    
Examination of type specimens has shown that Primula subansirica G.D. Pal is a Gesneriad and conspecific with Beccarinda cordifolia (Anthony) B.L. Burtt (Gesneriaceae), thus a reduction is made and a new synonymy is proposed.  相似文献   

18.
    
Three new species of Lonchaeidae are described from material reared from fig syconia in Japan: Silba inubiwa sp. nov., S. ishigaki sp. nov. and S. japonica sp. nov. Based on the taxonomy of these and similar species the boundaries of the genus Silba are re‐evaluated, and, as a result, it is considered that Setisquamalonchaea Morge is synonymous with Silba Macquart. A revised key and generic notes on the tribe Lonchaeini are provided.  相似文献   

19.
钝角宽刺甲Bioramix subaenescens(Schuster,1923)的原始描述过于简单,且缺少鉴别特征图。本文根据2009年在四川省马尔康市采集的钝角宽刺甲标本,对其作了形态重描述,并给出了详细的鉴别特征图和实物标本照片。此外,还编制了宽刺甲亚属Cardiobioramix中国已知种的检索表。检视标本保存于西华师范大学标本馆(MCWNU)和俄罗斯科学院动物研究所(ZIU)。  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号