Project description:Spiders represent one of the most studied arachnid orders. They are particularly intriguing from a cytogenetic point of view, due to their complex and dynamic sex chromosome determination systems. Despite intensive research on this group, cytogenetic data from African spiders are still mostly lacking. In this study, we describe the karyotypes of 38 species of spiders belonging to 16 entelegyne families from South Africa and Namibia. In the majority of analysed families, the observed chromosome numbers and morphology (mainly acrocentric) did not deviate from the family-level cytogenetic characteristics based on material from other continents: Tetragnathidae (2n? = 24), Ctenidae and Oxyopidae (2n? = 28), Sparassidae (2n? = 42), Gnaphosidae, Trachelidae and Trochanteriidae (2n? = 22), and Salticidae (2n? = 28). On the other hand, we identified interspecific variability within Hersiliidae (2n? = 33 and 35), Oecobiidae (2n? = 19 and 25), Selenopidae (2n? = 26 and 29) and Theridiidae (2n? = 21 and 22). We examined the karyotypes of Ammoxenidae and Gallieniellidae for the first time. Their diploid counts (2n? = 22) correspond to the superfamily Gnaphosoidea and support their placement in this lineage. On the other hand, the karyotypes of Prodidominae (2n? = 28 and 29) contrast with all other Gnaphosoidea. Similarly, the unusually high diploid number in Borboropactus sp. (2n? = 28) within the otherwise cytogenetically uniform family Thomisidae (mainly 2n? = 21-24) supports molecular data suggesting a basal position of the genus in the family. The implementation of FISH methods for visualisation of rDNA clusters facilitated the detection of complex dynamics of numbers of these loci. We identified up to five loci of the 18S rDNA clusters in our samples. Three different sex chromosome systems (X0, X1X20 and X1X2X30) were also detected among the studied taxa.
Project description:The family Eresidae C. L. Koch, 1850 is reviewed at the genus level. The family comprises nine genera including one new genus. They are: Adonea Simon, 1873, Dorceus C. L. Koch, 1846, Dresserus Simon, 1876, Eresus Walckenaer, 1805, Gandanameno Lehtinen, 1967, Loureediagen. n., ParadoneaLawrence, 1968, Seothyra Purcell, 1903, and Stegodyphus Simon, 1873. A key to all genera and major lineages is provided along with corresponding diagnoses, as well as descriptions of selected species. These are documented with collections of photographs, scanning electron micrographs, and illustrations. A new phylogeny of Eresidae based on molecular sequence data expands on a previously published analysis. A species of the genus Paradonea Lawrence, 1968 is sequenced and placed phylogenetically for the first time. New sequences from twenty Gandanameno Lehtinen, 1967 specimens were added to investigate species limits within the genus. The genus Loureediagen. n. is proposed to accommodate Eresus annulipes Lucas, 1857. Two species, Eresus semicanus Simon, 1908 and Eresus jerbae El-Hennawy, 2005, are synonymized with Loureedia annulipescomb. n. One new species, Paradonea presleyisp. n. is described. Eresus algericus El-Hennawy, 2004 is transferred to Adonea Simon, 1873. The female of Dorceus fastuosus C. L. Koch, 1846 is described for the first time. The first figures depicting Paradonea splendens (Lawrence, 1936) are presented.
Project description:Madeira island presents a unique spider diversity with a high number of endemic species, many of which are still poorly known. A recent biodiversity survey on the terrestrial arthropods of the native forest, Laurisilva, provided a large set of standardized samples from various patches throughout the island. Out of the fifty two species recorded, approximately 33.3% are Madeiran endemics, many of which had not been collected since their original description. Two new species to science are reported - Ceratinopsis n. sp. and Theridion n. sp. - and the first records of Poecilonetavariegata (Blackwall, 1841) and Tetragnathaintermedia Kulczynski, 1891 are reported for the first time for Madeira island. Considerations on species richness and abundance from different Laurisilva locations are presented, together with distribution maps for endemic species. These results contribute to a better understanding of spider diversity patterns and endemic species distribution in the native forest of Madeira island.
Project description:BackgroundSicariidae is a small family of cryptic and recluse spiders, with 178 species grouped into three genera: Hexophtalma, Loxosceles and Sicarius. Only the last two occur in Brazil, where 29 species are recorded, with a greater number of records in the Southeast and South regions. To date, there is no regionalized study of the distribution of these spiders in the Northeast of Brazil. We presented more than four decades of data on the distribution of sicariid spiders in the state of Bahia. Our research aimed to identify and evaluate the distribution of sicariid species in this region, characterizing them in their biomes and phytophysiognomies.MethodsData covers a period from 1983 to 2024, obtained from articles describing species recorded in Bahia and from three scientific collections from Brazilian institutions: Universidade Federal da Bahia (MHNBA); Instituto Butantan (IBSP); Universidade Federal de Minas Gerais (UFMG). Maps were produced using the QGIS 3.34.1 software, based on geographic coordinates obtained from the original literature, when provided. Species without information on geographic coordinates were georeferenced using the SpeciesLink (geoLoc tool) for the municipalities. Biomes were consulted on the georeference Brazilian institute website and the phytophysiognomies were ignored when not specified in the data of collections or original literature.ResultsWe confirmed 14 species of sicariid spiders in the state of Bahia, eight from the genus Loxosceles (i) and six from Sicarius. The species were recorded in 48 municipalities, located mainly in the Caatinga biome. We recorded a distribution expansion of seven species: Loxosceles amazonica, L. chapadensis, L. karstica, L. similis, Sicarius cariri, S. ornatus and S. tropicus. There is a difference in species composition in the two regions separated by the São Francisco River, an important geographic barrier especially for small invertebrates. More than 75% of the species were registered in the east side and about 20% exclusively in the west side: L. boqueirao, L. cardosoi, L. carinhanha. This suggests the need for future studies to evaluate additional variables that determine community structure, especially considering their low vagility and reclusive behavior. Although Sicarius are found almost exclusively in the Caatinga, there are isolated records from Restinga and dry forest enclaves in the Cerrado domain and Atlantic Forest areas. This reinforces the possibility of them being able to adapt to slightly wetter environments erase colonize and survive in seasonally dry rainforest areas. Unlike Sicarius (i), Loxosceles (i) occupy a wide variety of habitats in natural, urban and domiciliary situations. Many of the records here such as for Loxosceles boqueirao, L. cardosoi, L. carinhanha, L. chapadensis, L. karstica and L. troglobia were obtained at caves or nearby areas, which appear to be attractive habitats for these nocturnal spiders.
Project description:A new species of the genus Bannana Tong & Li, 2015 and a new species of the genus Trilacuna Tong & Li, 2007 are recorded from Xishuangbanna, Yunnan Province: Bannanazhengguoi Tong & Li, sp. nov. (♂♀) and Trilacunaaoxian Tong & Li, sp. nov. (♂♀). An identification key to species of the genus Bannana from Xishuangbanna is provided. Detailed diagnoses, descriptions, and photomicroscopy images of new species are provided.
Project description:Morphological study of 1,795 spiders from sites across Pakistan placed these specimens in 27 families and 202 putative species. COI sequences >400 bp recovered from 1,782 specimens were analyzed using neighbor-joining trees, Bayesian inference, barcode gap, and Barcode Index Numbers (BINs). Specimens of 109 morphological species were assigned to 123 BINs with ten species showing BIN splits, while 93 interim species included representatives of 98 BINs. Maximum conspecific divergences ranged from 0-5.3% while congeneric distances varied from 2.8-23.2%. Excepting one species pair (Oxyopes azhari-Oxyopes oryzae), the maximum intraspecific distance was always less than the nearest-neighbor (NN) distance. Intraspecific divergence values were not significantly correlated with geographic distance. Most (75%) BINs detected in this study were new to science, while those shared with other nations mainly derived from India. The discovery of many new, potentially endemic species and the low level of BIN overlap with other nations highlight the importance of constructing regional DNA barcode reference libraries.
Project description:This paper is the first in a series describing the previously unstudied cave spiders from Cyprus. Two new species, Dysderocrateskibrisensis sp. n. and Harpacteakalavachiana sp. n., are described. Detailed morphological descriptions and diagnostic characteristics are presented. This is the first report of the genus Dysderocrates Deeleman-Reinhold & Deeleman, 1988 from Cyprus.
Project description:Eight species of armored spiders belonging to two families, Pacullidae Simon, 1894 and Tetrablemmidae O. Pickard-Cambridge, 1873, are reported from Singapore. Five species are documented as new to science: Paculla bukittimahensis Lin & Li, sp. n. (male and female), Paculla globosa Lin & Li, sp. n. (male and female), Ablemma malacca Lin & Li, sp. n. (male and female), Singaporemma lenachanae Lin & Li, sp. n. (male and female), and Sulaimania brevis Lin & Li, sp. n. (male). The three known species are Brignoliella besutensis Lin, Li & Jäger, 2012, Brignoliella michaeli Lehtinen, 1981, and Singaporemma singulare Shear, 1978, of which the female of Brignoliella besutensis is described for the first time. For comparison, types of Singaporemma adjacens Lehtinen, 1981 from Vietnam, Singaporemma halongense Lehtinen, 1981 from Vietnam, Singaporemma singulare from Singapore and Sulaimania vigelandi Lehtinen, 1981 from Malaysia are studied and photographed.
Project description:A list of 34 thomisid species belonging to 21 genera collected in Jangxi Province of China is provided. Five new species are described: Angaeusxieluae Liu, sp. nov. (♂♀), Lysitelessubspirellus Liu, sp. nov. (♀), Oxytatemucunica Liu, sp. nov. (♀), Phartalingxiufengica Liu, sp. nov. (♀), Stephanopisxiangzhouica Liu, sp. nov. (♀). A new combination is proposed: Ebelingiaforcipata (Song & Zhu, 1993) comb. nov. (ex. Ebrechtella Dahl, 1907). Previously unknown females of E.forcipata (Song & Zhu, 1993), Oxytatebicornis Liu, Liu & Xu, 2017, and Xysticuslesserti Schenkel, 1963 are described for the first time. Stephanopis O Pickard-Cambridge, 1869, a genus previously known from Australasia and South America, is recorded from the Asian mainland for the first time.