THE PSAMOPHYTE HABITAT SPIDERS (ARACHNIDA, ARANEI) OF THE ZMIINI OSTROVY TRACT OF THE KANIV NATURE RESERVE

Abstract

B a c k g r o u n d . A herpetobius spiders of psammophilic vegetation areas of the sandy coast of the Kaniv Reservoir on the territory of the Zmiyini ostrovy tract, which is part of the Kaniv Nature Reserve, were studied. The variety of natural conditions of the reserve contributed to the formation of a high species diversity of flora and the corresponding complexes of living organisms, inextricably linked to these conditions of existence. All this gives reason to expect that the potential species richness of the local spider fauna of the Kaniv Nature Reserve may be one of the highest among other nature conservation areas of Ukraine. M e t h o d s . As the main collection method pitfall soil traps were used, installed in two periods: 06.06–07.01.2011 and 03–07.07.2017. The experimental plot was located near the sandy coast of the Kaniv Reservoir. The site is sand dunes overgrown with psamophyllous herbaceous vegetation near a pine-oak forest. Geographic coordinates of the experimental hospital: 49°50'28"N; 31°32'26"E. About 160 trap-days were worked, and 25 species of spiders, which are part of 10 families, were discovered. R e s u l t s . The vast majority of species are typical xerophiles that prefer thermophytic, arid or dry, open habitats with high levels of insolation. An annotated list of species is provided, which includes faunal material, geographical distribution, ecological features, and places of finds in the left-bank part of the Forest-Steppe Zone of Ukraine and for the Kaniv Nature Reserve. Among adult specimens, males predominate, their share is 63.5 %, the share of females is 36.5 %. The share of juvenile individuals among the total number of specimens is 38.3 %. A significant percentage of juvenile individuals is determined by the time of field work (during June), when the of spring-summer phenological group species gradually reduces its quantitative and qualitative presence in groups after the reproduction period. C o n c l u s i o n s . Taking into account the results of our research and data from literary sources, the list of spiders of the Snake Islands tract includes at least 63 species from 20 families. For the first time, 15 species of spiders from 8 families are indicated for the fauna of the Kaniv Reserve: Atypus muralis (Atypidae), Berlandina cinerea, Callilepis nocturna, Drassyllus praeficus, Haplodrassus kulczynskii, Zelotes electus, Zelotes longipes, Zelotes petrensis (Gnaphosidae), Alopecosa aculeata, Mustellicosa dimidiata (Lycosidae), Pholcus opilionoides (Pholcidae), Phlegra fasciata (Salticidae), Euryopis quinqueguttata (Theridiidae), Psammitis ninnii (Thomisidae) and Titanoeca spominima (Titanoecidae). For the territory of the Zmiyini ostrovy tract, 5 species of spiders belonging to 3 families were found to be new: Pardosa lugubris, Pirata piraticus, Xerolycosa miniata (Lycosidae), Thanatus formicinus (Philodromidae) and Steatoda albomaculata (Theridiidae). The value of the Shannon index for the grouping of Herpetobium spiders in areas of psammophilous vegetation is given – 3.219 bits. This index for the spider communities of the oak forest litter (fresh silverwood) is 3.738 bits. The value of the Jacquard index for species complexes of spiders of the compared biotopes is only 0.063. The low level of fauna relatedness is explained by the significant difference in the structure of the plant composition and the corresponding microclimatic conditions. Common to herpetobium spiders of both biotopes are 4 species of spiders: Arctosa lutetiana, Crustulina guttata, Drassodes lapidosus and Titanoeca schineri.