In the present study, some ecological factors were studied for Amphipoda at different depths. The Shannon, Margalef, and Hill indices were used to determine the  species diversity, richness and evenness, respectively. In addition, the association and niche overlap values were estimated. Indices of species richness and diversity were highest at 50 and 100m depths, respectively.  The or...

Five new species in the long-jawed orb-weaving spider genus Tetragnatha Latreille, 1804 are described from South America: amazonica sp. nov. (Venezuela); T. cristata (Argentina and Brazil); didorata (Brazil); oncognatha pradoi Brazil). A key to 21 of Argentina Brazil is provided, completing revision for these countries. The female cladognatha Bertkau, 1880 redescribed a neotype proposed, its ma...

Studying on Agaricales fungi collected from different parts of Mashhad and its suburbs (Khorasan province), 23 species were identificed. Among these, 18 species, namely, Lepiota cristata, Tricholoma sulphureum, Flammulina velutipes, Armillaria mellea, Pleurotus ostratus, Conocybe lactea, Agrocybe cylindracea, Mycena galopus, Psilocybe crobulus, Hypholoma   fasciculare, Agaricus bitorquis, Pholi...

Facilitation or competition occurs among plant species when one alter ameliorates the environment for another needs same sources of species. The objective this study was to determine facilitative competitive effect on Bromus variegatus, Festuca ovina, Koeleria cristata growing with isolated, Medicago papillosa, Astragalus microcephalus, Thymus parviflorus, and Hypericum scabrum, arranged in com...