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The paper presents data on 13 freshwater snail species: Theodoxus fluviatilis, Viviparus contectus, V. viviparus, Melanoides tuberculata, Bithynia tentaculata, B. leachii, Potamopyrgus antipodarum, Lithoglyphus naticoides, Marstoniopsis insubrica, Valvata cristata, V. pulchella, V. piscinalis and Borysthenia naticina, recorded over the last fifty years in the Wielkopolska district (W. Poland). Their distribution is shown on UTM/MGRS grid maps, and habitat information is provided. Among the discussed species, B. tentaculata (447 sites) and V. contectus (210 sites) are the most frequent in the region. Two alien species – M. tuberculata (two sites) and L. naticoides (seven sites) and the native B. naticina, recorded from five sites, are the least frequent.
The morphology of shell, penis, and female reproductive organs was studied in five populations of Pseudamnicola exilis (Frauenfeld) from southern Peloponnese and Kithira Island (Greece). No interpopulation differences were found in any of the characters. Thirty eight sequences of mitochondrial cytochrome oxidase subunit I (COI) and nuclear ribosomal 18S RNA genes were analysed. In COI 19 haplotypes, high haplotypy diversity, low nucleotide diversity in each population, and restricted gene flow between populations were found. NCA indicated allopatric fragmentation for all populations, and long-distance colonisation and/or past fragmentation for populations 4 and 5. Mismatch distribution in the most polymorphic population 4 reflected a bottleneck followed by population growth. The values of K2P interpopulation distances, though relatively low, pointed to congeneric distinct species within the Rissooidea. The monophyly of Pseudamnicola/Adrioinsulana clade was confirmed. Most probably the studied populations of Pseudamnicola were part of a flock of vicariant species little differentiated in morphology and ecology, many of which must have disappeared due to human impact.
A valvatiform hydrobiid gastropod, found in a spring at Dhiaselo, W of Sparta, N. Taigetos Mts., Peloponnese, Greece, was identified as Horatia hadei Gittenberger, 1982. Its protoconch sculpture, female reproductive organs and penis morphology are characteristic of Daphniola Radoman, 1973. Maximum likelihood phylogenetic analysis based on COI (cytochrome oxidase subunit I) fragments of mtDNA proved that the species is congeneric with D. exigua (A. Schmidt, 1856) and D. louisi Falniowski et Szarowska, 2000, and thus belongs to the genus Daphniola, and that D. hadei, D. exigua and D. louisi are species-level distinct taxa.
We studied the shell and penis morphology, and cytochrome oxidase subunit I (COI) gene sequences, in minute, valvatiform hydrobiid gastropods from Slovensky Kras, Slovakia. The morphology confirmed the assignment of the studied snails to the genus Hauffenia, while in the molecular tree they were placed within the Hydrobiidae, and not close to Hauffenia. The results indicate that the Slovak valvatiform hydrobiids are two taxa which presumably represent two genera: Hauffenia Pollonera, 1898 and Lobaumia Haase, 1993. More molecular data on the Austrian and Hungarian taxa are needed.
A population of Hydrobia sp. (Hydrobia ulvae Pennant and Hydrobia ventrosa Montagu) was studied in the Polish coastal zone (up to 3 nautical miles) of the Baltic Sea within the open coast of Polish Middle Pomerania. Abundance, wet biomass, and the frequency of Hydrobia were determined in the coastal waters, including estuaries of the Wieprza, Słupia, Łupawa, Łeba rivers and open coastal in the vicinity of Czołpino (Słowinski National Park) and Władysławowo. The frequency (F) of Hydrobia in the open coast of the Middle Pomerania amounted to 39%, while in the coastal zone of the open sea (Czołpino and Władysławowo) there were no snails. The abundance of Hydrobiidae, in the coastal zone surveyed, ranged from 0 to 398 specimens per m-2 of the bottom ( x = 33.7 spec. m–2). Wet biomass of this bivalve ranged from 0 to 12.0 gww m-2 ( x = 1.0 gww m-2). Apparently Hydrobia sp. has found better conditions for living and development in the estuary Middle Pomerania coast compared to open coastal. The abundance of this gastropods in the estuary zone was 27-fold higher than in the open coast and the wet weight was about 1.5-fold higher, respectively. Hydrobiidae plays an important role in the monitoring of benthos of the Baltic Sea, not constitutes a distinct food base of animals (fish and other hydrobionts).
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