Wyniki wyszukiwania - Biblioteka Nauki

Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl

Ograniczanie wyników

2 2011

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: isolated population

Sortuj według:

Ogranicz wyniki do:

Phenotypic response of Doronicum austriacum Jacq. (Asteraceae) to diverse mountain and lowland conditions

100%

Stachurska-Swakoń A. , Kuź K.

tom Vol. 59, nr 2

249-262

The knowledge of phenotypic response of rare and protected species provide useful information for the conservation and management strategies. Doronicum austriacum, a subalpine Central-European species has several lowland localities, which in Poland are regarded as glacial relicts. Diverse edaphic, climatic and coenotic conditions in particular localities give evidence to the broad ecological amplitude of the species. Based on data pertaining to three various populations occurring in different geographical regions (from South and Central Poland), different elevations a.s.l. (275-1350 m a.s.l.) and growing within different plant communities (subalpine tall-herb communities, mountain meadow, carr) an attempt has been made to characterise selected morphological, developmental and ecological features (like number of capitula and their diameter, effectiveness of reproduction, spatial distribution) and to test a hypothesis as to whether a lowland form of this species exists. The results indicate certain statistically significant differences (as number and diameter of capitula) between the study populations pertinent to plants at the generative stage. The distribution of the examined traits, however, falls within the range of species variability. The differences between averages are conditioned by the quality of the environment in terms of the soil moisture level, availability of mineral compounds and lighting, as well as by the degree of competition from other plants. The result of the experiment, involving transplantation of specimens into gardens, allow for the presumption that morphological features undergo environment-related modifications. At this stage of the studies, the idea of a morphologically different lowland form of the species cannot be supported.

The morphology of an unique population of Corynosoma strumosum (Acanthocephala, Polymorphidae) from the Caspian seal, Pusa caspica, in the land-locked Caspian Sea using SEM, with special notes on histopathology

100%

Amin O. M. , Heckmann R. A. , Halajian A. , El-Naggar A. M.

tom 56

nr 4

Over 700 specimens of Corynosoma strumosum (Rudolphi, 1802) Lühe, 1904 were collected from one young male Caspian seal, Pusa caspica (Gmelin) in the southern land-locked Caspian Sea in April, 2009. Collected worms showed consistent variations from those reported by other observers using light microscopy especially in proboscis hook and trunk spine patterns. SEM images revealed many features that have not been previously reported including the shape and distribution of trunk spines, dorsoventral differences in proboscis hooks and their organization, the baldness of anterior proboscis, the rough egg topography, epidermal micropores, and variations in the female gonopore. This isolated population of C. strumosum from the land-locked Caspian Sea is distinguished from others reported from open waters elsewhere by the distribution of trunk spines, consistently smaller size of trunk and testes, larger eggs, and fewer proboscis hooks. Histopathological sections reveal the invasive path of worms in host tissue with damage to intestinal villi and worm encapsulation. Information obtained from SEM studies and histopathological sections is reported for the first time.