1,721,167 research outputs found
Macrobiotus dariae sp. n., a new species of eutardigrade (Eutardigrada, Macrobiotidae) from Cyprus
No full textPilato, Giovanni, Bertolani, Roberto (2004): Macrobiotus dariae sp. n., a new species of eutardigrade (Eutardigrada, Macrobiotidae) from Cyprus. Zootaxa 638: 1-7, DOI: 10.5281/zenodo.15838
Thulinius, new generic name substituting for Thulinia Bertolani, 1981 (Tardigrada, Eutardigrada)
Full text linkDue to a homonymy with a genus of Trematoda described two years before, the name Thulinia Bertolani, 1981 cannot be used for a genus of tardigrades. Therefore, Thulinius nomen novum is proposed for a genus of tardigrades (Eutardigrada, Hypsibiidae), in substitution of Thulinia, junior homonym. The complicated taxonomic history of the genus Thulinius and especially of one of its species is discussed. The characteristics of the genus and the main distinctive characters of the species are also repoted
Presenza di un biotipo partenogenetico e suo effetto sul rapporto-sessi in Macrobiotus hufelansi (Tardigrada).
No full textIn samples of M. hufelandi found near Andalo (Trento) the sex ratio changes in different places of the same rock (from 1:1 to 1:4). The karyological analysis evidences that two populations attributable to the same species can be present in the same site, one being bisexual and diploid and the other thelytocous and triploid
Contributo alla cariologia dei Tardigradi. Osservazioni su Macrobiotus hufelandii.
No full textThe chromosome number in Macrobiotus hufelandi is 2n = 12 and n = 6 as in two other species of Macrobiotus (M. richtersi from Pisa and M. harmsworthi). The results differ from previous data which have stated 2n = 14 in M. hufelandi females. It is supposed that at least two sibling species are included in M. hufelandi
Partenogenesi geografica triploide in un Tardigrado.
No full textIn a bisexual population of Macrobiotus richtersi from Pisa the chromosome set is 2n = 12 and n = 6. It is also shown that in the same species, but in a different geographical territory (Modena), is present a prthenogenetic triploid (3n = 18) biotype. This kind of parthenogenesis is ameiotic. In the organs of the triploid individuals the number of cells is similar to that of the diploid population
Osservazioni cariologiche su biotipi bisessuati e partenogenetici di Hypsibius oberhaeuseri (Tardigrada).
No full textBisexual and unisexual (without males) biotypes are found in the tardigrade Hypsibius oberhaeuseri. The karyological analysis shows a chromosome number 2 = 12 and n = 6 in the bisexual biotype, while in the biotype without males there are 18 chromosomes in the mitosis and 18 univalents in the maturative division. Therefore a biotype of H. oberhaeuseri is triploid with an ameiotic parthenogenesia
La partenogenesi nei Tardigradi.
No full textSono analizzati diversi casi di partenogenesi nei tardigradi, tutti relativi a specie delle quali sono state trovate popolazioni anfimittiche
Osservazioni cariologiche su Isohypsibius augusti (Murray, 1907) e I. megalonyx Thulin, 1928 (Tardigrada) e ridescrizione delle due specie.
No full textOrganismi attribuiti dal punto di vista morfologico alla stessa specie sono stati esaminati sia dal punto di vista cariologico, sia da quello morfologico. E' emerso che due specie poste in passato in sinonimia avevano in realà numeri cromosomici diversi ed anche differenze tassonomiche rilevabili. Una delle due, inoltre, era caratterizzata sia da indivudui diploidi con maschi e femmine, che da femmine triploidi
Cytology and Systematics in Tardigrada.
No full textVengono riportati i primi risultati sullo studio della cariologia dei tardigradi e sugli aspetti della maturazione delle uova partenogenetiche in questo phylum
Variabilità numerica cellulare in alcuni tessuti di tardigradi.
No full textIn tardigrades the number of the storage cells, of the cells of the Malpighian tubules and of the 3rd ventral ganglion, varies. In the last case the swinging of the cell number, being not related to the growth, is due to a renewal of cells. Therefore tardigrades do not have a constant cell number in spite of a trend towards a secondary numerical constancy of some tissues, e. g. of the nervous tissue
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