Search results for "Spider"
showing 7 items of 97 documents
Molecular phylogeny of the spider family Sparassidae with focus on the genus Eusparassus and notes on the RTA-clade and ‘Laterigradae’
2013
The phylogeny of the spider family Sparassidae is comprehensively investigated using four molecular markers (mitochondrial COI and 16S; nuclear H3 and 28S). Sparassidae was recovered as monophyletic and as most basal group within the RTA-clade. The higher-level clade Dionycha was not but monophyly of RTA-clade was supported. No affiliation of Sparassidae to other members of the 'Laterigradae' (Philodromidae, Selenopidae and Thomisidae) was observed, and the crab-like posture of this group assumed a result of convergent evolution. Only Philodromidae and Selenopidae were found members of a supported clade, but together with Salticidae and Corinnidae, while Thomisidae was nested within the hig…
Crab spiders of the families Thomisidae and Philodromidae (Arachnida: Araneae) from Iran
2004
Spiders of the families Thomisidae and Philodromidae (Arachnida, Araneae) mainly collected in the mountainous areas of Iran in 1978 are taxonomically studied and classified into 21 species of 10 genera. Most species are illustrated and described on the basis of the present specimens. Except for only two species, Xysticus kulczynskii Wierzbicki 1902 and Synaema globosum (Fabricius 1775), already known from this country, 19 species are new records to the Iranian fauna. Of these, 14 species, Tmarus stellio Simon 1875, Xysticus ninnii Thorell 1872 (subsp. fusciventris Crome 1965), X. cristatus (Clerck 1758), X. kochi Thorell 1872, X. gallicus Simon 1875, Oxyptila nigrita Thorell 1875, Heriaeus …
Supervaroņu kritiskā literatūra – žanra specifika un tematiskie izaicinājumi
2016
Zinātniskajā darbā tiek analizēta supervaroņu žanra specifika, īpašu vērību veltot supervaroņu īpašībām, kā arī komiksu specifikai. Teorētiskā daļa sastāv no literatūras pārskata par izvēlēto tēmu. Praktiskā daļa koncentrējas uz supervaroņu analīzi, kā arī izvēlēto komiksi no amerikāņu, japāņu un Eiropas valstīm salīdzinājumu analīzi. Pētījuma mērķis ir siegt salīdzinošu Supermena, Spidermena un Betmena analīzi, kā arī amerikāņu, japāņu un Eiropas komiksu analīzi. Iegūtie rezultāti iezīmē galvenās specifikas, kas raksturīgas supervaroņu žanrā, un ļauj iemācīties vairāk par supervaroņu žanra vērtībam un īpašībām. Lai sasniegtu mērķi, darbā sīkāk tika analizētas supervaroņu žanra specifika, s…
Automatic image‐based identification and biomass estimation of invertebrates
2020
Understanding how biological communities respond to environmental changes is a key challenge in ecology and ecosystem management. The apparent decline of insect populations necessitates more biomonitoring but the time-consuming sorting and expert-based identification of taxa pose strong limitations on how many insect samples can be processed. In turn, this affects the scale of efforts to map and monitor invertebrate diversity altogether. Given recent advances in computer vision, we propose to enhance the standard human expert-based identification approach involving manual sorting and identification with an automatic image-based technology. We describe a robot-enabled image-based identificat…
Kinetic properties of catecholoxidase activity of tarantula hemocyanin
2008
Phenoloxidases occur in almost all organisms, being essentially involved in various processes such as the immune response, wound healing, pigmentation and sclerotization in arthropods. Many hemocyanins are also capable of phenoloxidase activity after activation. Notably, in chelicerates, a phenoloxidase has not been identified in the hemolymph, and thus hemocyanin is assumed to be the physiological phenoloxidase in these animals. Although phenoloxidase activity has been shown for hemocyanin from several chelicerate species, a characterization of the enzymatic properties is still lacking. In this article, the enzymatic properties of activated hemocyanin from the tarantula Eurypelma californi…
Silk-Water: a dynamic duo
2010
Testing the effectiveness of pyrazine defences against spiders
2020
Insects live in a dangerous world and may fall prey to a wide variety of predators, encompassing multiple taxa. As a result, selection may favour defences that are effective against multiple predator types, or target-specific defences that can reduce predation risk from particular groups of predators. Given the variation in sensory systems and hunting tactics, in particular between vertebrate and invertebrate predators, it is not always clear whether defences, such as chemical defences, that are effective against one group will be so against another. Despite this, the majority of research to date has focused on the role of a single predator species when considering the evolution of defended…