|
Hexophthalma Hahni
''Hexophthalma hahni'' ( synonyms ''Sicarius hahni'' and ''Sicarius testaceus''), known along with other members of the genus as the six-eyed sand spider, is a member of the family Sicariidae, found in deserts and other sandy places in southern Africa. Due to their flattened stance and laterigrade legs, they are also sometimes known as six-eyed crab spiders. Its specific name honours Carl Wilhelm Hahn. Venom All species of ''Hexophthalma'' produce venom that can have necrotic (dermonecrotic) effects, capable of causing serious or even life-threatening wounds, particularly if the wound becomes infected or the venom spreads in the body. The necrotic effects are caused by a family of proteins related to sphingomyelinase D Sphingomyelin phosphodiesterase D (EC 3.1.4.41, sphingomyelinase D) is an enzyme of the sphingomyelin phosphodiesterase family with systematic name sphingomyelin ceramide-phosphohydrolase. These enzymes catalyse the hydrolysis of sphingomyelin, res ..., present i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Friedrich Karsch
Ferdinand Anton Franz Karsch or Karsch-Haack (2 September 1853, in Münster – 20 December 1936, in Berlin) was a German arachnologist, entomologist and anthropologist. The son of a doctor, Karsch was educated at the Friedrich Wilhelm University in Berlin and published a thesis on the gall wasp in 1877. From 1878 to 1921 he held the post of curator at the Museum für Naturkunde Berlin. Between 1873 and 1893, he published a catalogue of the spiders of Westphalia; he also published numerous articles on the specimens that the museum received from various explorers and naturalists working in Africa, in China, in Japan, in Australia, etc. This publication of others' work sometimes led to disputes over priority and nomenclature, for example with Pickard-Cambridge. Alongside his zoological activities, he published many works on sexuality and, in particular, homosexuality in both the animal kingdom and in so-called "primitive" peoples, including ''Das gleichgeschlechtliche Lebe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synonym (taxonomy)
The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently. * In botanical nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name. For example, Linnaeus was the first to give a scientific name (under the currently used system of scientific nomenclature) to the Norway spruce, which he called ''Pinus abies''. This name is no longer in use, so it is now a synonym of the current scientific name, ''Picea abies''. * In zoology, moving a species from one genus to another results in a different binomen, but the name is considered an alternative combination rather than a synonym. The concept of synonymy in zoology is reserved for two names at the same rank that refers to a taxon at that rank - for example, the name ''Papilio prorsa'' Linnaeus, 1758 is a junior synonym of ''Papilio levana'' Linnaeus, 1758, being names for different seasonal forms of the species now referred to as ''Araschnia le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sicariidae
Sicariidae is a family of six-eyed venomous spiders known for their potentially necrotic bites. The family consists of three genera and about 160 species. Well known spiders in this family include the brown recluse spider and the six-eyed sand spider. Description ''Loxosceles'', commonly known as "recluse spiders" or "violin spiders", is distributed nearly worldwide in warmer areas. ''Hexophthalma'' and '' Sicarius'', commonly known as "sand spiders" or "assassin spiders", live in the deserts of southern Africa and South to Central America, respectively. They are known for their self-burying behavior and the ability to go for long periods without food or water. All members have six eyes arranged in three groups of two (dyads). Violin spiders are usually brownish with a darker brown characteristic violin marking on the cephalothorax. They are also haplogyne, meaning the females possessing unsclerotised genitals. ''Hexophthalma'' and ''Sicarius'' resemble crab spiders and lack ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Southern Africa
Southern Africa is the southernmost subregion of the African continent, south of the Congo and Tanzania. The physical location is the large part of Africa to the south of the extensive Congo River basin. Southern Africa is home to a number of river systems; the Zambezi River being the most prominent. The Zambezi flows from the northwest corner of Zambia and western Angola to the Indian Ocean on the coast of Mozambique. Along the way, the Zambezi River flows over the mighty Victoria Falls on the border between Zambia and Zimbabwe. Victoria Falls is one of the largest waterfalls in the world and a major tourist attraction for the region. Southern Africa includes both subtropical and temperate climates, with the Tropic of Capricorn running through the middle of the region, dividing it into its subtropical and temperate halves. Countries commonly included in Southern Africa include Angola, Botswana, the Comoros, Eswatini, Lesotho, Madagascar, Malawi, Mauritius, Mozambique, Namib ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. However, only about 14% of these had been described by 2011. All species (except viruses) are given a two-part name, a "binomial". The first part of a binomial is the genus to which the species belongs. The second part is called the specific name or the specific epithet (in botanical nomenclature, also sometimes i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carl Wilhelm Hahn
Carl Wilhelm Hahn (Lat. ''Carolus Guilielmus Hahn'', 16 December 1786 – 7 November 1835) was a German zoologist and author of the first German monograph on spiders. C. W. Hahn was an all-round natural scientist – not at all unusual for his time. Surprisingly, he seems to have been almost forgotten. Even the few biographical dates that have been published in secondary literature are not always correct as clarified by P. Sacher in his "attempt at a Biography". Life and lifework Carl Wilhelm Christian Hahn was born in Weingartsgreuth, Upper Franconia, as the first son of Johann Michael Hahn (1734–1824), who was court and palace gardener on the estate of Friedrich Heinrich von Seckendorff, Baron von Seckendorff, later palace gardener for Count Friedrich von Pückler. He obeyed the general call to arms as early as 1813, and served as a quartermaster, and in 1816, received his honourable discharge. Afterwards, he lived with his parents in Fürth, and according to Hahn, made ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Necrosis
Necrosis () is a form of cell injury which results in the premature death of cells in living tissue by autolysis. Necrosis is caused by factors external to the cell or tissue, such as infection, or trauma which result in the unregulated digestion of cell components. In contrast, apoptosis is a naturally occurring programmed and targeted cause of cellular death. While apoptosis often provides beneficial effects to the organism, necrosis is almost always detrimental and can be fatal. Cellular death due to necrosis does not follow the apoptotic signal transduction pathway, but rather various receptors are activated and result in the loss of cell membrane integrity and an uncontrolled release of products of cell death into the extracellular space. This initiates in the surrounding tissue an inflammatory response, which attracts leukocytes and nearby phagocytes which eliminate the dead cells by phagocytosis. However, microbial damaging substances released by leukocytes would crea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphingomyelin Phosphodiesterase D
Sphingomyelin phosphodiesterase D (EC 3.1.4.41, sphingomyelinase D) is an enzyme of the sphingomyelin phosphodiesterase family with systematic name sphingomyelin ceramide-phosphohydrolase. These enzymes catalyse the hydrolysis of sphingomyelin, resulting in the formation of ceramide 1-phosphate and choline: : sphingomyelin + H2O \rightleftharpoons ceramide 1-phosphate + choline or the hydrolysis of 2-lysophosphatidylcholine to give choline and 2-lysophosphatidate. Sphingomyelin phosphodiesterase D activity is shared by enzymes with a wider substrate range, classified as phospholipases D or lipophosphodiesterase II . Sphingomyelinases D are produced by some spiders in their venoms, specifically the brown recluse (''Loxosceles reclusa''), by arthropods such as ticks, or pathogenic bacteria and fungi. Pathogenicity is expressed through different mechanisms, such as membrane destabilization, cell penetration, inflammation of the lungs and cutaneous lesions, common following brown rec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spiders Of Africa
Spiders ( order Araneae) are air-breathing arthropods that have eight legs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species diversity among all orders of organisms. Spiders are found worldwide on every continent except for Antarctica, and have become established in nearly every land habitat. , 50,356 spider species in 132 families have been recorded by taxonomists. However, there has been debate among scientists about how families should be classified, with over 20 different classifications proposed since 1900. Anatomically, spiders (as with all arachnids) differ from other arthropods in that the usual body segments are fused into two tagmata, the cephalothorax or prosoma, and the opisthosoma, or abdomen, and joined by a small, cylindrical pedicel, however, as there is currently neither paleontological nor embryological evidence that spiders ever had a separate t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
