ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Gemmules of sponges from a warm lake (1996)
    Oxford BSL : Blackwell Science Ltd
    Freshwater biology 35 (1996), S. 0 
    Details
    ISSN: 1365-2427
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: 1. Two types of gemmules were found, each in a different species of sponge, from the warm monomictic Lake Kinneret: (i) clustered gemmules, sharing the pneumatic layer of the gemmular capsule and resembling gemmules of Eunapius; (ii) gemmules that develop non-synchronously, containing amphidisc spicules within the gemmular capsule and resembling those of Ephydatia. Algal cells were not detected within either type of gemmule although they exist in the developed sponges.2. Sponges began producing gemmules in the lake with the onset of lake drawdown and ceased when lake level was minimal. The gemmules hatched when the lake level began to rise.3. Under experimental conditions gemmules hatched between 13 and 35 °C. Germination was optimal at 20–25 °C. Chilling of young gemmules prior to incubation at 25 °C improved germination rate.4. The percentage of germinating dry gemmules diminished 4–6 months after their collection from the lake. None germinated after 10 months. Submerged gemmules maintained high viability with ageing (up to 100% germination 18 months after collection). Desiccation influenced gemmule viability over time, by both decreasing the percentage of germinating gemmules and increasing the lag time before onset of germination.5. Gemmules kept in the dark germinated significantly less than those illuminated for 12 h day
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2427.1996.00486.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    STREAMS IN MEDITERRANEAN CLIMATE REGIONS: Abiotic Influences and Biotic Responses to Predictable Seasonal Events (1999)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Ecology, Evolution, and Systematics 30 (1999), S. 51-81 
    Details
    ISSN: 0066-4162
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology
    Notes: Abstract Streams in mediterranean-climate regions (areas surrounding the Mediterranean Sea, parts of western North America, parts of west and south Australia, southwestern South Africa and parts of central Chile) are physically, chemically, and biologically shaped by sequential, predictable, seasonal events of flooding and drying over an annual cycle. Correspondingly, aquatic communities undergo a yearly cycle whereby abiotic (environmental) controls that dominate during floods are reduced when the discharge declines, which is also a time when biotic controls (e.g. predation, competition) can become important. As the dry season progresses, habitat conditions become harsher; environmental pressures may again become the more important regulators of stream populations and community structure. In contrast to the synchronous input of autumn litterfall in forested temperate streams, riparian input to mediterranean-type streams is more protracted, with fall and possibly spring peaks occurring in streams in the Northern Hemisphere and a summer peak existing in their Southern Hemisphere counterparts. We present 25 testable hypotheses that relate to the influence of the stream hydrograph on faunal richness, abundance, and diversity; species coexistence; seasonal changes in the relative importance of abiotic and biotic controls on the biotic structure; riparian inputs and the relative importance of heterotrophy compared to autotrophy; and the impact of human activities on these seasonally water-stressed streams. Population increases in mediterranean-climate regions (particularly in fertile regions) result in an intensification of the competition for water among different users; consequently, water abstraction, flow regulation, increased salinity, and pollution severely limit the ability of the streams to survive as sustainable, self-regulated systems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1146/annurev.ecolsys.30.1.51
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Cadmium uptake and toxicity to water hyacinth: Effect of repeated exposures under controlled conditions (1990)
    Springer
    Bulletin of environmental contamination and toxicology 44 (1990), S. 149-157 
    Details
    ISSN: 1432-0800
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01702375
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Habitat condition and fish assemblage structure in a coastal mediterranean stream (Yarqon, Israel) receiving domestic effluent (2000)
    Springer
    Hydrobiologia 422-423 (2000), S. 319-330 
    Details
    ISSN: 1573-5117
    Keywords: urban stream ; Multi Dimensional Scaling ; stream pollution ; BOD
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The Yarqon stream is the largest urban stream in Israel. In the past 40 y it was severely impacted by human action. Fish kills occur along the polluted sections of the stream almost regularly following winter floods and when poor-quality effluent is discharged into the stream. These events attest to the serious ecological state of the Yarqon stream. We studied the interaction between habitat conditions and fish assemblage structure for four consecutive years. Comparison of certain water quality variables among selected sites along the upper and central stream sections of the Yarqon indicated that the two stream sections differ significantly in electric conductivity and organic load (BOD) but not in temperature and dissolved oxygen. The average species richness and fish abundance in the upper, relatively undisturbed section is significantly higher than in the downstream, upper reach of the central section where domestic effluents enter the stream. In contrast, fish biomass is usually higher in the central stream section. Organic load was the only factor among the four water quality variables measured that significantly correlates with variables of the fish assemblage. A curve fit analysis between organic load and fish species richness and abundance suggests a threshold at ca. 10 mg l-1 BOD, above which most fish species totally avoid polluted habitats. Separate Multi Dimensional Scaling (MDS) analyses of water quality variables and fish assemblages clearly separated between the sites in the upper and the central stream sections. When the result of the fish MDS analysis was graphically superimposed on the result of the water quality MDS analysis, we found a close overlap between the two, suggesting a strong association between water quality and the fish assemblage structure in the Yarqon stream.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1017040017238
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Comparative evaluation of the larvivorous fish Gambusia affinis and Aphanius dispar as mosquito control agents (1994)
    Springer
    Hydrobiologia 284 (1994), S. 137-146 
    Details
    ISSN: 1573-5117
    Keywords: biological control ; mosquito control ; Gambusia ; Aphanius
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Under laboratory conditions Aphanius was more successful than Gambusia in preying upon the 3rd, 4th and pupal stages of mosquitoes. The reverse was found for the first two instars. However. Aphanius consumed more 2nd instar larvae under the cover of vegetation when larger fish were able to penetrate shallow water and feed on the mosquito larvae. The two species showed a similar prey-size selection except for Aphanius of the medium size (31–35 mm) which ate larger larvae than Gambusia of the same size range. When provided access to the surface, neither fish species showed any adverse effect at oxygen levels as low as 0.5 mg l-1 (6% saturation). When denied access to the surface, both species behaved ‘normally’ at oxygen levels as low as 1.3 mg l-1 (15% saturation). This study suggests that Gambusia affinis and Aphanius dispar can complement each other as mosquito control agents in different habitat conditions. We suggest that in mosquito infested situation which are characterized by high organic matter and low oxygen levels biological control could best be achieved by introduction of a range of sizes of both fish species. Repeated introductions of the fish, in large enough numbers, may be required for ad-hoc alleviation of a mosquito problem. Best results are thus to be expected in relatively small water bodies such as oxidation ponds.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00006885
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Seston dynamics and tripton sedimentation in the pelagic zone of a shallow eutrophic lake (1976)
    Springer
    Hydrobiologia 51 (1976), S. 225-231 
    Details
    ISSN: 1573-5117
    Keywords: Tripton ; Seston ; Sedimentation ; Benthos
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The transport of organic matter from the water column to the sediment and the relationship between the dynamics of the settleable fraction and that of the total suspended particulate matter were studied in shallow eutrophic Lake Wingra, Wisconsin. Tripton sedimentation was closely related to the dynamics of seston with a lag of 2 to 4 weeks. Sedimentation rate of tripton ranged from 0 to 8 g m−2 day−1 (in May and August respectively). Relative t0 the standing crop 0f seston the maximum sedimentation rate was 8% seston per day (in September). The annual tripton sedimentation was estimated at 632 g dry weight or 215 g C per m2 which was equivalent t0 55% of the annual phytoplankton production and 42% of the phytoplankton and macrophytes annual production. It was estimated that 70% of the settling organic matter is decomposed annually, consequently only a small fraction 0f tripton is involved in the long term accumulation of bottom deposits. Factors influencing tripton sedimentation are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00005748
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    facet.materialart.
    Unknown
    Effect of an exotic prey on the feeding pattern of a predatory snail (2002)
    Elsevier
    Details
    Publication Date: 2002-07-01
    Print ISSN: 0141-1136
    Electronic ISSN: 1879-0291
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Geosciences
    Published by Elsevier
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 8
    facet.materialart.
    Unknown
    Comparative evaluation of the larvivorous fish Gambusia affinis and Aphanius dispar as mosquito control agents (1994)
    Springer
    Details
    Publication Date: 1994-05-01
    Print ISSN: 0018-8158
    Electronic ISSN: 1573-5117
    Topics: Biology
    Published by Springer
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 9
    facet.materialart.
    Unknown
    Prolonged Lag in Population Outbreak of an Invasive Mussel: A Shifting-Habitat Model (2004)
    Springer
    Details
    Publication Date: 2004-01-01
    Print ISSN: 1387-3547
    Electronic ISSN: 1573-1464
    Topics: Biology
    Published by Springer
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 10
    facet.materialart.
    Unknown
    Seston dynamics and tripton sedimentation in the pelagic zone of a shallow eutrophic lake (1976)
    Springer
    Details
    Publication Date: 1976-12-01
    Print ISSN: 0018-8158
    Electronic ISSN: 1573-5117
    Topics: Biology
    Published by Springer
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...