|
Southern Black Widow
''Latrodectus mactans'', known as southern black widow or simply black widow, and the shoe-button spider, is a venomous species of spider in the genus ''Latrodectus''. The females are well known for their distinctive black and red coloring and for the fact that they will occasionally eat their mates after reproduction. The species is native to North America. The venom can cause pain and other symptoms, but is rarely fatal to healthy humans. Taxonomy ''Latrodectus mactans'' was first described by Johan Christian Fabricius in 1775, placing it in the genus '' Aranea''. It was transferred to the genus ''Latrodectus'' in 1837 by Charles Walckenaer and is currently placed in the family Theridiidae of the order Araneae. The species is closely related to ''Latrodectus hesperus'' (western black widow) and ''Latrodectus variolus'' (northern black widow). Members of the three species are often confused with the genus '' Steatoda'', the false widows. Prior to 1970, when the current taxonomi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johan Christian Fabricius
Johan Christian Fabricius (7 January 1745 – 3 March 1808) was a Danish zoologist, specialising in "Insecta", which at that time included all arthropods: insects, arachnids, crustaceans and others. He was a student of Carl Linnaeus, and is considered one of the most important entomologists of the 18th century, having named nearly 10,000 species of animals, and established the basis for the modern insect classification. Biography Johan Christian Fabricius was born on 7 January 1745 at Tønder in the Duchy of Schleswig, where his father was a doctor. He studied at the gymnasium at Altona and entered the University of Copenhagen in 1762. Later the same year he travelled together with his friend and relative Johan Zoëga to Uppsala, where he studied under Carl Linnaeus for two years. On his return, he started work on his , which was finally published in 1775. Throughout this time, he remained dependent on subsidies from his father, who worked as a consultant at Frederiks Hospita ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Northern Black Widow
''Latrodectus variolus'', the northern black widow spider or northern widow, is a venomous species of spider in the genus ''Latrodectus'' of the family Theridiidae. The population is closely related to the southern black widow, ''Latrodectus mactans'', and the western black widow, ''Latrodectus hesperus'', of the genus. In North America, the species is commonly found in Middle Atlantic states (New Jersey, Delaware, Maryland). During the April–May mating season, it can travel north along the coast as far as Massachusetts. It is also found in Connecticut in the late summer, and rarely, in southern Ontario and southern Quebec, Michigan, and at least as far northwest as parts of Wisconsin. A bite may cause latrodectism, and requires medical attention in the case of increasingly severe discomfort or spreading local redness accompanied by severe pain. The LD-50 has been measured in mice as ; each spider contains about of venom. Unlike for the related ''Latrodectus mactans'', no an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arachnids
Arachnida () is a Class (biology), class of joint-legged invertebrate animals (arthropods), in the subphylum Chelicerata. Arachnida includes, among others, spiders, scorpions, ticks, mites, pseudoscorpions, opiliones, harvestmen, Solifugae, camel spiders, Amblypygi, whip spiders and Thelyphonida, vinegaroons. Almost all adult arachnids have eight Arthropod leg, legs, although the front pair of legs in some species has converted to a sensory function, while in other species, different appendages can grow large enough to take on the appearance of extra pairs of legs. The term is derived from the Ancient Greek, Greek word (''aráchnē'', 'spider'), from the myth of the hubristic human weaver Arachne, who was turned into a spider. Almost all Extant taxon, extant arachnids are terrestrial animal, terrestrial, living mainly on land. However, some inhabit freshwater environments and, with the exception of the pelagic zone, marine environments as well. They comprise over 100,000 named ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chilopods
Centipedes (from New Latin , "hundred", and Latin , " foot") are predatory arthropods belonging to the class Chilopoda (Ancient Greek , ''kheilos'', lip, and New Latin suffix , "foot", describing the forcipules) of the subphylum Myriapoda, an arthropod group which includes millipedes and other multi-legged animals. Centipedes are elongated segmented (metameric) creatures with one pair of legs per body segment. All centipedes are venomous and can inflict painful bites, injecting their venom through pincer-like appendages known as forcipules. Despite the name, centipedes can have a varying number of legs, ranging from 30 to 382. Centipedes always have an odd number of pairs of legs; no centipede has exactly 100. Like spiders and scorpions, centipedes are predominantly carnivorous. Their size ranges from a few millimetres in the smaller lithobiomorphs and geophilomorphs to about in the largest scolopendromorphs. Centipedes can be found in a wide variety of environments. They ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diplopods
Millipedes are a group of arthropods that are characterised by having two pairs of jointed legs on most body segments; they are known scientifically as the class Diplopoda, the name derived from this feature. Each double-legged segment is a result of two single segments fused together. Most millipedes have very elongated cylindrical or flattened bodies with more than 20 segments, while pill millipedes are shorter and can roll into a tight ball. Although the name "millipede" derives from the Latin for "thousand feet", no species was known to have 1,000 or more until the discovery of ''Eumillipes persephone'', which can have over 1,300 legs. There are approximately 12,000 named species classified into 16 orders and around 140 families, making Diplopoda the largest class of myriapods, an arthropod group which also includes centipedes and other multi-legged creatures. Most millipedes are slow-moving detritivores, eating decaying leaves and other dead plant matter. Some eat fungi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Woodlice
A woodlouse (plural woodlice) is an isopod crustacean from the polyphyleticThe current consensus is that Oniscidea is actually triphyletic suborder Oniscidea within the order Isopoda. They get their name from often being found in old wood. The first woodlice were marine isopods which are presumed to have colonised land in the Carboniferous, though the oldest known fossils are from the Cretaceous period. They have many common names and although often referred to as terrestrial isopods, some species live semiterrestrially or have recolonised aquatic environments. Woodlice in the families Armadillidae, Armadillidiidae, Eubelidae, Tylidae and some other genera can roll up into a roughly spherical shape ( conglobate) as a defensive mechanism; others have partial rolling ability, but most cannot conglobate at all. Woodlice have a basic morphology of a segmented, dorso-ventrally flattened body with seven pairs of jointed legs, specialised appendages for respiration and like ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cannibalism (zoology)
Cannibalism is the act of consuming another individual of the same species as food. Cannibalism is a common ecological interaction in the animal kingdom and has been recorded in more than 1,500 species. Human cannibalism is well documented, both in ancient and in recent times. The rate of cannibalism increases in nutritionally poor environments as individuals turn to members of their own species as an additional food source.Elgar, M.A. & Crespi, B.J. (1992) ''Cannibalism: ecology and evolution among diverse taxa'', Oxford University Press, Oxford ngland New York. Cannibalism regulates population numbers, whereby resources such as food, shelter and territory become more readily available with the decrease of potential competition. Although it may benefit the individual, it has been shown that the presence of cannibalism decreases the expected survival rate of the whole population and increases the risk of consuming a relative. Other negative effects may include the increased ri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecdysis
Ecdysis is the moulting of the cuticle in many invertebrates of the clade Ecdysozoa. Since the cuticle of these animals typically forms a largely inelastic exoskeleton, it is shed during growth and a new, larger covering is formed. The remnants of the old, empty exoskeleton are called exuviae. After moulting, an arthropod is described as ''teneral'', a ''callow''; it is "fresh", pale and soft-bodied. Within one or two hours, the cuticle hardens and darkens following a tanning process analogous to the production of leather. During this short phase the animal expands, since growth is otherwise constrained by the rigidity of the exoskeleton. Growth of the limbs and other parts normally covered by the hard exoskeleton is achieved by transfer of body fluids from soft parts before the new skin hardens. A spider with a small abdomen may be undernourished but more probably has recently undergone ecdysis. Some arthropods, especially large insects with tracheal respiration, expand thei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palpal Bulb
The two palpal bulbs – also known as palpal organs and genital bulbs – are the copulatory organs of a male spider. They are borne on the last segment of the pedipalps (the front "limbs" of a spider), giving the spider an appearance often described as like wearing boxing gloves. The palpal bulb does not actually produce sperm, being used only to transfer it to the female. Palpal bulbs are only fully developed in adult male spiders and are not completely visible until after the final moult. In the majority of species of spider, the bulbs have complex shapes and are important in identification. Structure The palpal bulb of a mature male spider is borne on the last segment of the pedipalp. This segment usually has touch-sensitive hairs (setae) with nerves leading to them. The bulb itself is entirely without nerves, and hence without sensory organs and muscles, since these depend on nerves for their functioning, although some spiders have one or two muscles external to the bulb and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hawaii
Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only state geographically located within the tropics. Hawaii comprises nearly the entire Hawaiian archipelago, 137 volcanic islands spanning that are physiographically and ethnologically part of the Polynesian subregion of Oceania. The state's ocean coastline is consequently the fourth-longest in the U.S., at about . The eight main islands, from northwest to southeast, are Niihau, Kauai, Oahu, Molokai, Lānai, Kahoolawe, Maui, and Hawaii—the last of these, after which the state is named, is often called the "Big Island" or "Hawaii Island" to avoid confusion with the state or archipelago. The uninhabited Northwestern Hawaiian Islands make up most of the Papahānaumokuākea Marine National Monument, the United States' largest protected ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hawaiian Islands
The Hawaiian Islands ( haw, Nā Mokupuni o Hawai‘i) are an archipelago of eight major islands, several atolls, and numerous smaller islets in the North Pacific Ocean, extending some from the island of Hawaii in the south to northernmost Kure Atoll. Formerly the group was known to Europeans and Americans as the Sandwich Islands, a name that James Cook chose in honor of the 4th Earl of Sandwich, the then First Lord of the Admiralty. Cook came across the islands by chance when crossing the Pacific Ocean on his Third Voyage in 1778, on board HMS ''Resolution''; he was later killed on the islands on a return visit. The contemporary name of the islands, dating from the 1840s, is derived from the name of the largest island, Hawaii Island. Hawaii sits on the Pacific Plate and is the only U.S. state that is not geographically connected to North America. It is part of the Polynesia subregion of Oceania. The state of Hawaii occupies the archipelago almost in its entirety (includin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Latrodectus Geometricus
''Latrodectus geometricus'', commonly known as the brown widow, brown button spider, grey widow, brown black widow, house button spider or geometric button spider, is one of the widow spiders in the genus ''Latrodectus''. As such, it is a 'cousin' to the more infamous ''Latrodectus mactans'' (black widow). ''L. geometricus'' has black and white patterns on the sides of its abdomen as well as an orange-yellow colored hourglass shape. Their eggs are easily identified by points that project from all over the egg sacs. ''L. geometricus'' are found all over the world, but are believed to originate in South America. Their bites, though painful, are not considered to be dangerous. Taxonomy ''L. geometricus'' derives its name from the geometric patterning on its abdomen. However, the spider's coloring can and does darken over time and the pattern may become obscured. Similar widows include the ''L. rhodesiensis'', a brown-colored relative of ''L. geometricus'' which is native to Z ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
