1,721,005 research outputs found
Pseudosmittia fabioi sp. n., a new species from Sardinia (Diptera: Chironomidae, Orthocladiinae)
Full text linkA new species of Pseudosmittia Edwards 1932, P. fabioi, from Sardinia (Palearctic region), is described and figured as male and female. The generic diagnosis is emended based on characters found in the new species. The species is characterized by a triangular anal point with microtrichia at apex (not projecting beyond tergite IX), an inferior volsella characterized by a rounded lobe with a setose accessory lobe adpressed to the gonocoxite, a well developed tooth-like projection on the outer margin of the gonostylus, the lack of acrostichals and an antenna with 6 flagellomeres in female
Mercury Bioaccumulation: Laboratory-reared Chironomus riparius vs. Indigenous Chironomids
No full textA new benthic quality index for Italian lakes : how to approach with different lake types?
Full text linkPseudosmittia fabioi Boggero, Zaupa & Rossaro, 2014 (Diptera: Chironomidae: Orthocladiinae) a new junior synonym of Prosmittia verae Krasheninnikov & Makarchenko, 2008
Full text linkPseudosmittia fabioi Boggero, Zaupa & Rossaro, 2014 was found to be conspecific with Prosmittia verae Krasheninnikov & Makarchenko, 2008 after examination of original description and illustrations. Accordingly, Ps. fabioi is placed in junior synonymy with Pr. verae, new synonymy. The transfer of Ps. fabioi to the genus Prosmittia allows to state that the female of Ps. fabioi (Boggero et al., 2014) is the first description of the female of the genus Prosmittia
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Chironomids from Southern Alpine running waters : ecology, biogeography
Full text linkThe chironomid fauna living in running waters in the Southern Alps was investigated from an ecological and biogeographical point of view: 202 species were identified (not including terrestrial species). It must be emphasised that species identification is tentative within some genera, especially those awaiting revision (e.g., Boreoheptagyia, Chaetocladius). Although much taxonomic work was done in the past on the chironomid Alpine fauna, there are still many unsolved problems.
Most of the species found are widespread in the Palearctic Region, with no evidence of bio-geographical barriers separating different Alpine sectors. Really a relatively high number of species reported from the northern and western side (France, Switzerland, Austria) of the Alps was not captured on the southern side (Italy), whereas most species found on the southern side are also present on the northern one. Very few species are reported from southern side only. Lack of sampling, imperfect taxonomic knowledge and different environmental conditions between the northern and southern sides may be responsible of this result. A comparison of the fauna of the southern Alps with the fauna of the Apennines suggests that the differences are probably more related to ecological conditions (lack of glaciers in the Apennines) than to biogeographical barriers.
Different chironomid assemblages colonise manifold habitat types: strict cold-stenothermal species tolerating high current velocity (e.g., Diamesa latitarsis - steinboecki group) are almost the sole inhabitants of kryal biotopes, while other cold-stenothermal species are restricted to cold springs (Diamesa dampfi, D. incallida, Tokunagaia rectangularis, T. tonollii), there are also species characteristic of hygropetric habitats (Syndiamesa edwardsi, S. nigra) or restricted to lacustrine habitats (Corynoneura lacustris, Paratanytarsus austriacus). It must be emphasised that different responses to environmental factors can be observed between species belonging to the same genus (e.g., Diamesa, Eukiefferiella, Orthocladius, Paratrichocladius), so species identification is really needed for a good ecological work. Water temperature, current velocity, substrate type are the most critical factors, sometime chironomid species appear to be rather opportunistic and their presence or absence cannot be clearly related to a well defined range of values of environmental variables: be it a lack of knowledge or a real datum will be the task of future studies.
The waters of the Alps are still relatively unpolluted, but hydraulic stress due to river damming and canalization is a serious problem for macrofauna conservation, and as the glaciers retreat, the species confined to the glacial snouts are at risk of extinction, some of them possibly even before their existence be discovered
Benthic macroinvertebrates as indicators in lakes
Full text linkBenthic macroinvertebrates are considered to be good indicators of the trophic status
of lakes but in the Mediterranean area gaps in knowledge on taxonomical and
autoecological traits of species hinder their potential as indicators. Seventy-eight
Italian lakes were sampled, belonging to 10 types according to morphometrical,
geographical and geological parameters. An unsupervised neural network (SOM analysis)
was carried out using 65 Chironomid and Oligochaete species collected in 1865
samples. he accordance between lake types and species assemblages was tested.
Indicator weight of species was calculated considering their optima for trophic
variables (dissolved oxygen, TP, transparency). A Benthic Quality Index (BQI) and a
weighted diversity index were then calculated to test their potential as indicators of
trophic status of lakes. Alpine, volcanic and large profundal lakes were separated into
diferent clusters, characterized by diferent communities, chemical and morphometrical
parameters. On the contrary, other lake types with similar trophic status were
grouped together, showing similar taxa assemblages. BQI values were in agreement
with the trophic condition of lakes, while the weighted diversity index showed low
values for alpine lakes due to low species numbers
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