|
Seycellesa
''Seycellesa'' is a genus of spiders in the family Theridiidae. It consists of only its type species: ''Seycellesa braueri'', which is endangered and endemic to the Seychelles. Taxonomic history The type species was initially described in 1898 by the French naturalist Eugène Simon, who placed it in the genus '' Theridion''. He chose the specific epithet ''braueri'' to honor A. Brauer at the University of Marburg. His description was based on a male specimen. British arachnologist Michael Roberts described a junior synonym, ''T. purifum'', in 1978. The specific name was described as "an arbitrary combination of letters". His description was based on a female specimen. Michael Saaristo synonymized ''T. purifum'' with ''T. braueri'' in 1999. In 2006, Saaristo circumscribed a new genus for ''T. braueri''. He named it ''Robertia'' after Michael Roberts. However, that generic name was invalid due to a senior homonym: the synapsid genus '' Robertia''. In 2008, Ahmet Koçak and Muha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theridiidae
Theridiidae, also known as the tangle-web spiders, cobweb spiders and comb-footed spiders, is a large family of Araneomorphae, araneomorph spiders first described by Carl Jakob Sundevall in 1833. This diverse, globally distributed family includes over 3,000 species in 124 genus, genera, and is the most common arthropod found in human dwellings throughout the world. Theridiid spiders are both Entelegynae, entelegyne, meaning that the females have a genital plate, and Cribellum, ecribellate, meaning that they spin sticky capture silk instead of woolly silk. They have a comb of serrated bristles (setae) on the Arthropod leg, tarsus of the fourth leg. The family includes some model organisms for research, including the List of medically significant spider bites, medically important Latrodectus, widow spiders. They are important to studies characterizing their venom and its clinical manifestation, but widow spiders are also used in research on spider silk and sexual biology, including ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eugène Simon
Eugène Louis Simon (; 30 April 1848 – 17 November 1924) was a French naturalist who worked particularly on insects and spiders, but also on birds and plants. He is by far the most prolific spider taxonomist in history, describing over 4,000 species. Work on spiders His most significant work was ''Histoire Naturelle des Araignées'' (1892–1903), an encyclopedic treatment of the spider genera of the world. It was published in two volumes of more than 1000 pages each, and the same number of drawings by Simon. Working at the Muséum National d'Histoire Naturelle in Paris, it took Simon 11 years to complete, while working at the same time on devising a taxonomic scheme that embraced the known taxa. Simon described a total of 4,650 species, and as of 2013 about 3,790 species are still considered valid. The International Society of Arachnology offers a Simon Award recognising lifetime achievement. The Eocene fossil spider species '' Cenotextricella simoni'' was named in his ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cinnamomum Verum
''Cinnamomum verum'', called true cinnamon tree or Ceylon cinnamon tree, is a small evergreen tree belonging to the family Lauraceae, native to Sri Lanka. The inner bark of several other ''Cinnamomum'' species are also used to make cinnamon, but ''C. verum'' has a more subtle flavor. Description ''Cinnamomum verum'' trees are 10–15 metres (30–50 feet) tall. The leaves are ovate-oblong in shape and 7–18 cm (3–7 inches) long. The flowers, which are arranged in panicles, have a greenish color and a distinct odour. The fruit is a purple 1cm drupe containing a single seed. Cultivation The old botanical synonym for the tree, ''Cinnamomum zeylanicum'', is derived from Sri Lanka's former name, Ceylon. Sri Lanka still produces 80–90% of the world's supply of ''C. verum'', which is also cultivated on a commercial scale in the Seychelles, Madagascar and Tanzania. Cultivars There are several different cultivars of ''Cinnamomum verum'' based on the taste of bark: * Type 1 – si, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Invasive Species
An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species adversely affect habitats and bioregions, causing ecological, environmental, and/or economic damage. The term can also be used for native species that become harmful to their native environment after human alterations to its food webfor example the purple sea urchin (''Strongylocentrotus purpuratus'') which has decimated kelp forests along the northern California coast due to overharvesting of its natural predator, the California sea otter (''Enhydra lutris''). Since the 20th century, invasive species have become a serious economic, social, and environmental threat. Invasion of long-established ecosystems by organisms is a natural phenomenon, but human-facilitated introductions have greatly increased the rate, scale, and geographic range of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IUCN Red List
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biological species. It uses a set of precise criteria to evaluate the extinction risk of thousands of species and subspecies. These criteria are relevant to all species and all regions of the world. With its strong scientific base, the IUCN Red List is recognized as the most authoritative guide to the status of biological diversity. A series of Regional Red Lists are produced by countries or organizations, which assess the risk of extinction to species within a political management unit. The aim of the IUCN Red List is to convey the urgency of conservation issues to the public and policy makers, as well as help the international community to reduce species extinction. According to IUCN the formally stated goals of the Red List are to provi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Opisthosoma
The opisthosoma is the posterior part of the body in some arthropods, behind the prosoma (cephalothorax). It is a distinctive feature of the subphylum Chelicerata (arachnids, horseshoe crabs and others). Although it is similar in most respects to an abdomen (and is often referred to as such), the opisthosoma is differentiated by its inclusion of the respiratory organs (book lungs or book gills) and the heart. Segments The number of segments and appendages on the opisthosoma vary. Scorpions have 13, but the first is only seen during its embryological development. Other arachnids have fewer; harvestmen, for instance, have only ten. In general, appendages are absent or reduced, although in horseshoe crabs they persist as large plate-like limbs, called opercula or branchiophores, bearing the book gills, and that function in locomotion and gas exchange. In most chelicerates the opisthosomal limbs are greatly reduced and persist only as specialized structures, such as the silk-producing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sternum (arthropod Anatomy)
The sternum (pl. "sterna") is the ventral portion of a segment of an arthropod thorax or abdomen. In insects, the sterna are usually single, large sclerites, and external. However, they can sometimes be divided in two or more, in which case the subunits are called sternites, and may also be modified on the terminal abdominal segments so as to form part of the functional genitalia, in which case they are frequently reduced in size and development, and may become internalized and/or membranous. For a detailed explanation of the terminology, see Kinorhynchs have tergal and sternal plates too, though seemingly not homologous with those of arthropods.Sørensen, M. V. et al. Phylogeny of Kinorhyncha based on morphology and two molecular loci. PLoS One 10, 1–33 (2015). Ventrites are externally visible sternites. Usually the first sternite is covered up, so that vertrite numbers do not correspond to sternid numbers. The term is also used in other arthropod groups such as crustaceans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Labium (arthropod Mouthpart)
The mouthparts of arthropods have evolution, evolved into a number of forms, each adaptation, adapted to a different style or mode of feeding. Most mouthparts represent modified, paired appendages, which in ancestral forms would have appeared more like legs than mouthparts. In general, arthropods have mouthparts for cutting, chewing, piercing, sucking, shredding, siphoning, and filtering. This article outlines the basic elements of four arthropod groups: insects, myriapods, crustaceans and chelicerates. Insects are used as the model, with the novel mouthparts of the other groups introduced in turn. Insects are not, however, the Arthropod#Classification of arthropods, ancestral form of the other arthropods discussed here. Insects Insect mouthparts exhibit a range of forms. The earliest insects had chewing mouthparts. Specialisation includes mouthparts modified for siphoning, piercing, sucking and sponging. These modifications have evolved a number of times. For example, m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glossary Of Spider Terms
This glossary describes the terms used in formal descriptions of spiders; where applicable these terms are used in describing other arachnids. Links within the glossary are shown . Terms A Abdomen or opisthosoma: One of the two main body parts ( tagmata), located towards the posterior end; see also Abdomen § Other animals Accessory claw: Modified at the tip of the in web-building spiders; used with to grip strands of the web Anal tubercle: A small protuberance (tubercule) above the through which the anus opens Apodeme → Apophysis (plural apophyses): An outgrowth or process changing the general shape of a body part, particularly the appendages; often used in describing the male → Atrium (plural atria): An internal chamber at the entrance to the in female haplogyne spiders B Bidentate: Having two Book lungs: Respiratory organs on the ventral side (underside) of the , in front of the , opening through narrow slits; see also Book lungs Branchial operculum â ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chelicerae
The chelicerae () are the mouthparts of the subphylum Chelicerata, an arthropod group that includes arachnids, horseshoe crabs, and sea spiders. Commonly referred to as "jaws", chelicerae may be shaped as either articulated fangs, or similarly to pincers. Some chelicerae, such as those found on nearly all spiders, are hollow and contain (or are connected to) venom glands, and are used to inject venom into prey or a perceived threat. In ''Pisaurina mira'', also known as the nursery web spider, the chelicerae are utilized to snatch the prey once it becomes within reach, facilitating the "sit-and-wait ambush predator" behavior. Both pseudoscorpions and harvestmen have structures on their chelicerae that are used for grooming (papillae in pseudoscorpions, cheliceral teeth in Opiliones). Types Chelicerae can be divided into three kinds: jackknife chelicerae, scissor chelicerae, and 3-segmented chelate chelicerae. Jackknife chelicerae The jackknife chelicera is subchelate (with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carapace
A carapace is a Dorsum (biology), dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tortoises, the underside is called the plastron. Crustaceans In crustaceans, the carapace functions as a protective cover over the cephalothorax (i.e., the fused head and thorax, as distinct from the abdomen behind). Where it projects forward beyond the eyes, this projection is called a rostrum (anatomy), rostrum. The carapace is Calcification, calcified to varying degrees in different crustaceans. Zooplankton within the phylum Crustacea also have a carapace. These include Cladocera, ostracods, and Isopoda, isopods, but isopods only have a developed "cephalic shield" carapace covering the head. Arachnids In arachnids, the carapace is formed by the fusion of prosomal tergites into a single Plate (animal anatomy), plate which carries the e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Woodland
A woodland () is, in the broad sense, land covered with trees, or in a narrow sense, synonymous with wood (or in the U.S., the ''plurale tantum'' woods), a low-density forest forming open habitats with plenty of sunlight and limited shade (see differences between British, American, and Australian English explained below). Woodlands may support an understory of shrubs and herbaceous plants including grasses. Woodland may form a transition to shrubland under drier conditions or during early stages of primary or secondary succession. Higher-density areas of trees with a largely closed canopy that provides extensive and nearly continuous shade are often referred to as forests. Extensive efforts by conservationist groups have been made to preserve woodlands from urbanization and agriculture. For example, the woodlands of Northwest Indiana have been preserved as part of the Indiana Dunes. Definitions United Kingdom ''Woodland'' is used in British woodland management to mean tre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
