ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • Articles  (98)
  • Hindawi  (98)
  • American Meteorological Society
  • Blackwell Publishing Ltd
  • Copernicus
  • De Gruyter
  • Institute of Electrical and Electronics Engineers
  • Springer Science + Business Media
  • 2020-2022
  • 2010-2014  (98)
  • 1985-1989
  • 1980-1984
  • 1960-1964
  • 2014  (48)
  • 2012  (50)
  • 1982
  • Journal of Marine Biology  (44)
  • 129000
  • Biology  (98)
  • Mathematics
Collection
  • Articles  (98)
Publisher
  • Hindawi  (98)
  • American Meteorological Society
  • Blackwell Publishing Ltd
  • Copernicus
  • De Gruyter
  • +
Years
  • 2020-2022
  • 2010-2014  (98)
  • 1985-1989
  • 1980-1984
  • 1960-1964
Year
Topic
  • Biology  (98)
  • Mathematics
  • 1
    Publication Date: 2012-10-05
    Description: While gradual allometric changes of shells are intrinsically driven by genotype, morphometrical shifts can also be modulated by local environmental conditions. Consequently the common use of a unique dimension (usually length) to assess bivalves’ growth may mask phenotypic differences in valve shape among populations. A morphometric exhaustive study was conducted on Manila clam, Ruditapes philippinarum, by acquiring data in the French Arcachon Bay (intrasite phenotypic variability) and by comparing with other sites in the literature (intersite phenotypic variability). 2070 shells were subsampled, weighted, and automatically measured using TNPC software. Some ratios’ values indicate a relatively round and globular shape shell in comparison with other sites confirming poor conditions for some individuals. Among adult clams, three main morphological groups were identified and discussed according to spatial considerations. Allometric relations for pairs of shell descriptors were determined by testing classical linear and piecewise regression models on log-transformed relation of Huxley. A significant shape change correlated to size was observed; it corresponds to the second year of life of the clam. Relationships between density, disease, and shell shape are demonstrated and discussed related to other potential factors affecting shell shape. Finally, consequences on population regulation are addressed.
    Print ISSN: 1687-9481
    Electronic ISSN: 1687-949X
    Topics: Biology
    Published by Hindawi
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2012-09-04
    Description: Shallow water zooxanthellate zoanthids are a common component of the coral reef ecosystems of the Caribbean. Despite this, their species diversity remains poorly understood. In this study, collected Palythoa, Zoanthus, Isaurus, and Terrazoanthus specimens from the waters of Florida were phylogenetically examined to obtain a better understanding of zoanthid species diversity in the Caribbean. Surprisingly, the results from analyses utilizing three DNA markers (mitochondrial 16S ribosomal DNA, cytochrome oxidase subunit I, and the internal transcribed spacer of ribosomal DNA) showed the presence of at least eleven species, of which up to four appear undescribed. Additionally, the presence of the genus Terrazoanthus in the Caribbean was confirmed for the first time. Attempts to match phylogenetic species or clades with original literature were hampered by vague and short original descriptions, and it is clear that for Atlantic Palythoa and Zoanthus species an in-depth and multidisciplinary investigation is needed to reconcile recent phylogenetic results such as in this study with traditional taxonomy. Furthermore, most shallow water zoanthid species from Florida were observed to have close, sister-species relationships with previously investigated species in the Pacific Ocean. These results indicate that many brachycnemic zoanthid species likely had a Caribbean-Pacific distribution until the formation of the Isthmus of Panama. However, due to inadvertent redescriptions, overall species diversity in these two common genera is likely much lower than literature indicates.
    Print ISSN: 1687-9481
    Electronic ISSN: 1687-949X
    Topics: Biology
    Published by Hindawi
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2012-08-16
    Description: Vertical patterns of early summer chlorophyll a (Chl a) concentration from the Indian Ocean are presented, as well as the variations of depth and size-fractioned Chl a in the deep chlorophyll maximum (DCM). A total of 38 stations were investigated from 12 April to 5 May 2011, with 8 discrete-depth samples (7 fixed and 1 variable at real DCM) measured at each station. Depth-integrated Chl a concentration (∑Chl
    Print ISSN: 1687-9481
    Electronic ISSN: 1687-949X
    Topics: Biology
    Published by Hindawi
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2012-09-12
    Description: Documenting larval behavior is critical for building an understanding of larval dispersal dynamics and resultant population connectivity. Nocturnal diel vertical migration (DVM), a daily migration towards the surface of the water column at night and downward during the day, can profoundly influence dispersal outcomes. Via laboratory experiments we investigated whether marine gastropod Kelletia kelletii larvae undergo nocturnal DVM and whether the behavior was influenced by the presence of light, ontogeny, and laboratory culturing column height. Larvae exhibited a daily migration pattern consistent with nocturnal diel vertical migration with lower average vertical positioning (ZCM) during day-time hours and higher vertical positioning at night-time hours. ZCM patterns varied throughout ontogeny; larvae became more demersal as they approached competency. There was no effect of column height on larval ZCM. DVM behavior persisted in the absence of light, indicating a possible endogenous rhythm. Findings from field plankton tows corroborated laboratory nocturnal DVM findings; significantly more K. kelletii were found in surface waters at midnight compared to at noon. Unraveling the timing of and the cues initiating DVM behavior in K. kelletii larvae can help build predictive models of dispersal outcomes for this emerging fishery species.
    Print ISSN: 1687-9481
    Electronic ISSN: 1687-949X
    Topics: Biology
    Published by Hindawi
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2012-09-15
    Description: In this paper we examined the histology of three commercially valuable species of precious corals (Paracorallium japonicum, Corallium elatius, and C. konojoi) from the Ryukyu Archipelago. In order to observe their inner structure, samples were thin sectioned and examined with a digital light microscope. Colonies of C. konojoi had thicker coenenchyme and larger autozooids than those of C. elatius and P. japonicum. The sclerites of the three species tended to be concentrated in the outer layers of coenenchyme. The gastric cavities of autozooids of all three species were found to be relatively empty. Some symbiotic polychates were observed in the axis of P. japonicum. As well, a zoanthid (Corallizoanthus tsukaharai) was often observed living on the coenenchyme surface of P. japonicum. It is hoped our observations will provide a good foundation of future study of Japanese Coralliidae corals.
    Print ISSN: 1687-9481
    Electronic ISSN: 1687-949X
    Topics: Biology
    Published by Hindawi
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2012-08-17
    Description: This study constitutes the first report of the gametogenic cycle of the scleractinian corals Solenastrea bournoni and Stephanocoenia intersepta. Tissue samples were collected near Ft. Lauderdale, Florida, USA between July 2008 and November 2009 and processed for histological examination in an effort to determine reproductive mode and potential spawning times. Both S. bournoni and S. intersepta are gonochoric, broadcast spawning species. Gametogenesis of S. bournoni began in April or May while S. intersepta had a much longer oogenic cycle that began in December with spermatogenesis beginning in July. Though spawning was not observed in situ, spawning was inferred from the decrease of late stage gametes in histological samples. In addition, histological observations of oocyte resorption and released spermatozoa were used to corroborate spawning times. Data indicate that S. bournoni spawns in September while S. intersepta spawns after the full moon in late August or early September.
    Print ISSN: 1687-9481
    Electronic ISSN: 1687-949X
    Topics: Biology
    Published by Hindawi
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 2012-06-29
    Description: The vacuole of utricles, the outermost cell layer of the siphonous green seaweed, Codium minus, had numerous single needles and needle bundles. The crystals composing each needle appeared arranged in a twisted configuration, both ends were pointed, and each needle was contained in a matrix or membrane; bundles of needles appeared enclosed by a matrix. Chemical and electron diffraction analysis indicated that the needles consisted of calcium oxalate. This is the first paper on terrestrial plant-like raphides in an alga.
    Print ISSN: 1687-9481
    Electronic ISSN: 1687-949X
    Topics: Biology
    Published by Hindawi
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 2012-05-09
    Description: The relationships between the abundance of demersal resources, environmental variables, and fishing pressure in the north-western Ionian Sea in the last two decades were evaluated. Data on the density collected during seventeen trawl surveys carried out from 1985 to 2005 were used. The following species were considered: Aristaeomorpha foliacea, Nephrops norvegicus, and Parapenaeus longirostris for crustaceans; Merluccius merluccius, Phycis blennoides, and Mullus barbatus for teleost fish. The recruitment index was also considered for N. norvegicus, P. longirostris, M. merluccius and Mullus barbatus. Six candidate models were evaluated for each density and recruitment data set either combining fishing effort with global (NAO) and regional (SST and precipitation) climatic indices, or models separately involving fishing effort, NAO, or regional climatic indices as the only predictive variable. Model selection was carried out using an information-theoretical approach that applies Akaike’s Information Criterion (AIC). High changes over time were observed for the density data and recruitment indices in each species. Apart from hake abundance and recruitment data, for which a clear positive relationship with the NAO index alone was detected, the changes observed in the other species seem to be the consequence of the interaction between bottom-up effects linked to changes in physical environment and top-down ones due to the fishing pressure.
    Print ISSN: 1687-9481
    Electronic ISSN: 1687-949X
    Topics: Biology
    Published by Hindawi
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Publication Date: 2012-02-29
    Description: Macroalgal and urchin barren communities are alternately stable and persist in the Aleutians due to sea otter presence and absence. In the early 1990s a rapid otter population decline released urchins from predation and caused a shift to the urchin-dominated state. Despite increases in urchin abundance, otter numbers continued to decline. Although debated, prey quality changes have been implicated in current otter population status. This study examined otter prey abundance, size, biomass, and potential energy density in remnant kelp forest and urchin-dominated communities to determine if alternate stable states affect prey quality. Findings suggest that although urchin barrens provide more abundant urchin prey, individual urchins are smaller and provide lower biomass and potential energy density compared to kelp forests. Shifts to urchin barrens do affect prey quality but changes are likely compensated by increased prey densities and are insufficient in explaining current otter population status in the Aleutians.
    Print ISSN: 1687-9481
    Electronic ISSN: 1687-949X
    Topics: Biology
    Published by Hindawi
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Publication Date: 2012-02-23
    Description: We present evidence that a clade of bacteria in the Oceanospirillaceae is widely distributed in Porites spp. and other hermatypic corals. Bacteria 16S rDNA clone libraries were prepared from community genomic DNA extracted from Porites compressa and Porites lobata surface mucus and adjacent seawater collected along a line transect off Maui. Phylogenetic affiliations of operational taxonomic units (OTUs) defined at the 97% level of nucleotide identity varied within and between the respective Porites spp. along the transect and differed from those in the seawater. One OTU (C7-A01), however, occurred in all mucus samples from both Porites species. C7-A01c affiliates with a clade of uncultivated Oceanospirillum-like bacteria; the nearest neighbors of this OTU have been reported only in the surface mucus layer of Porites spp. and other stony corals, in reef-dwelling invertebrates, and the corallivorous six-banded angelfish, Pomacanthus sexstriatus.
    Print ISSN: 1687-9481
    Electronic ISSN: 1687-949X
    Topics: Biology
    Published by Hindawi
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...