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Palps
Pedipalps (commonly shortened to palps or palpi) are the second pair of appendages of chelicerates – a group of arthropods including spiders, scorpions, horseshoe crabs, and sea spiders. The pedipalps are lateral to the chelicerae ("jaws") and anterior to the first pair of walking legs. Overview Pedipalps are composed of six segments or articles: the coxa, the trochanter, the femur, the short patella, the tibia, and the tarsus. In spiders, the coxae frequently have extensions called maxillae or gnathobases, which function as mouth parts with or without some contribution from the coxae of the anterior legs. The limbs themselves may be simple tactile organs outwardly resembling the legs, as in spiders, or chelate weapons ( pincers) of great size, as in scorpions. The pedipalps of Solifugae are covered in setae, but have not been studied in detail. Comparative studies of pedipalpal morphology may suggest that leg-like pedipalps are primitive in arachnids. At present, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxyopes Salticus
''Oxyopes salticus'' is a species of lynx spider, commonly known as the striped lynx spider, first described by Hentz in 1845. Its habitat tends to be grasses and leafy vegetation; grassy, weedy fields, and row crops.Brady 1964 Description Adult specimens have some color variation between orange, cream and brown. Adult females typically have stripes on both the carapace and abdomen, though on many specimens, the stripes are more pronounced on the abdomen. There is a generally a diamond cardiac mark, and macrosetae covering legs I-IV. There is a broad clypeus. Adult females range in size from ~5-6mm, and adult males range in size ~4-5mm. Range Eastern United States from Massachusetts and Iowa south to Florida and Texas, along Mexican border, north along Pacific coast to Oregon. Also much of South and Central AmericaBrady 1964 Recently, ''O.salticus'' has been found in great numbers on the Big Island of Hawai'i as well as the island of Maui (see picture to the right).Insects of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seta
In biology, setae (singular seta ; from the Latin word for " bristle") are any of a number of different bristle- or hair-like structures on living organisms. Animal setae Protostomes Annelid setae are stiff bristles present on the body. They help, for example, earthworms to attach to the surface and prevent backsliding during peristaltic motion. These hairs make it difficult to pull a worm straight from the ground. Setae in oligochaetes (a group including earthworms) are largely composed of chitin. They are classified according to the limb to which they are attached; for instance, notosetae are attached to notopodia; neurosetae to neuropodia. Crustaceans have mechano- and chemosensory setae. Setae are especially present on the mouthparts of crustaceans and can also be found on grooming limbs. In some cases, setae are modified into scale like structures. Setae on the legs of krill and other small crustaceans help them to gather phytoplankton. It captures them and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schizomida
Schizomida (common name shorttailed whipscorpion) is an order of arachnids, generally less than in length. The order is not yet widely studied. About 300 species of schizomids have been described worldwide, most belonging to the Hubbardiidae family. A systematic review including a full catalogue may be found in Reddell & Cokendolpher (1995). The Schizomida is sister to the order Uropygi, the two clades together forming the Thelyphonida. Based on molecular clock dates, both orders likely originated in the late Carboniferous somewhere in the tropics of Pangea, and the Schizomida underwent substantial diversification starting in the Cretaceous. The oldest known fossils of the group are from the Mid-Cretaceous Burmese amber of Myanmar, which are assignable to the Hubbardiidae. E. O. Wilson has identified schizomids as among the "groups of organisms that desperately need experts to work on them." Taxonomy Schizomids are grouped into three families: * Calcitronidae † (fossil) ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amblypygi
Amblypygi is an ancient order of arachnid chelicerate arthropods also known as African cave-dwelling spiders, whip spiders and tailless whip scorpions (not to be confused with whip scorpions or vinegaroons that belong to the related order Thelyphonida). The name "amblypygid" means "blunt tail", a reference to a lack of the flagellum that is otherwise seen in whip scorpions. Amblypygids possess no silk glands or venomous fangs. They rarely bite if threatened, but can grab fingers with their pedipalps, resulting in thorn-like puncture injuries. As of 2016, 5 families, 17 genera and around 155 species had been discovered and described. They are found in tropical and subtropical regions worldwide; they are mainly found in warm and humid environments and like to stay protected and hidden within leaf litter, caves, or underneath bark. Some species are subterranean; all are nocturnal. Fossilized amblypygids have been found dating back to the Carboniferous period, such as ''Weygoldti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Raptorial
The term ''raptorial'' implies much the same as ''predatory'' but most often refers to modifications of an arthropod's foreleg that make it function for the grasping of prey while it is consumed, where the gripping surfaces are formed from the opposing faces of two successive leg segments (''see illustration''). This is distinctly different from the grasping mechanism of a structure such as a scorpion's claw (a " chela") in which one of the opposing surfaces is an articulated digit, and not a leg segment. While this is most widely known in mantises, similarly modified legs can be found in some crustaceans (e.g., mantis shrimp), and various insect families, such as Mantispidae, Belostomatidae, Nepidae, and Naucoridae (all members of these groups have raptorial forelegs). There are numerous other lineages within various insect families that have raptorial forelegs, most commonly seen in the family Reduviidae, but also including several different families of flies, and a few thri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudoscorpion
Pseudoscorpions, also known as false scorpions or book scorpions, are small, scorpion-like arachnids belonging to the order Pseudoscorpiones, also known as Pseudoscorpionida or Chelonethida. Pseudoscorpions are generally beneficial to humans since they prey on clothes moth larvae, carpet beetle larvae, booklice, ants, mites, and small flies. They are tiny, and are rarely noticed due to their small size, despite being common in many environments. When people do see pseudoscorpions, especially indoors, they are often mistaken for ticks or small spiders. Pseudoscorpions often carry out phoresis, a form of commensalism in which one organism uses another for the purpose of transport. Characteristics Pseudoscorpions belong to the class Arachnida. They are small arachnids with a flat, pear-shaped body, and pincer-like pedipalps that resemble those of scorpions. They usually range from in length. Pennsylvania State University, DepartmentEntomological Notes: Pseudoscorpion Fact Shee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ricinulei
Ricinulei is a small order of arachnids. Like most arachnids, they are predatory, eating small arthropods. They occur today in west-central Africa (''Ricinoides'') and the Neotropics (''Cryptocellus'' and ''Pseudocellus'') as far north as Texas. As of 2021, 91 extant species of ricinuleids have been described worldwide, all in the single family Ricinoididae. In older works they are sometimes referred to as Podogona. Due to their obscurity they do not have a proper common name, though in academic literature they are occasionally referred to as hooded tickspiders. In addition to the three living genera, there are fossil species from the upper Carboniferous of Euramerica and the Cretaceous Burmese amber. Description The most important general account of ricinuleid anatomy remains the 1904 monograph by Hans Jacob Hansen and William Sørensen. Useful further studies can be found in, e.g., the work of Pittard and Mitchell, Gerald Legg and L. van der Hammen. Body Ricinulei are typical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antennae (biology)
Antennae ( antenna), sometimes referred to as "feelers", are paired appendages used for sensing in arthropods. Antennae are connected to the first one or two segments of the arthropod head. They vary widely in form but are always made of one or more jointed segments. While they are typically sensory organs, the exact nature of what they sense and how they sense it is not the same in all groups. Functions may variously include sensing touch, air motion, heat, vibration (sound), and especially smell or taste. Antennae are sometimes modified for other purposes, such as mating, brooding, swimming, and even anchoring the arthropod to a substrate. Larval arthropods have antennae that differ from those of the adult. Many crustaceans, for example, have free-swimming larvae that use their antennae for swimming. Antennae can also locate other group members if the insect lives in a group, like the ant. The common ancestor of all arthropods likely had one pair of uniramous (unbranched) a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hox Genes
Hox genes, a subset of homeobox genes, are a group of related genes that specify regions of the body plan of an embryo along the head-tail axis of animals. Hox proteins encode and specify the characteristics of 'position', ensuring that the correct structures form in the correct places of the body. For example, Hox genes in insects specify which appendages form on a segment (for example, legs, antennae, and wings in fruit flies), and Hox genes in vertebrates specify the types and shape of vertebrae that will form. In segmented animals, Hox proteins thus confer segmental or positional identity, but do not form the actual segments themselves. Studies on Hox genes in ciliated larvae have shown they are only expressed in future adult tissues. In larvae with gradual metamorphosis the Hox genes are activated in tissues of the larval body, generally in the trunk region, that will be maintained through metamorphosis. In larvae with complete metamorphosis the Hox genes are mainly expres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insect
Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs of jointed legs, compound eyes and one pair of antennae. Their blood is not totally contained in vessels; some circulates in an open cavity known as the haemocoel. Insects are the most diverse group of animals; they include more than a million described species and represent more than half of all known living organisms. The total number of extant species is estimated at between six and ten million; In: potentially over 90% of the animal life forms on Earth are insects. Insects may be found in nearly all environments, although only a small number of species reside in the oceans, which are dominated by another arthropod group, crustaceans, which recent research has indicated insects are nested within. Nearly all insects hatch f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crustaceans
Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group can be treated as a subphylum under the clade Mandibulata. It is now well accepted that the hexapods emerged deep in the Crustacean group, with the completed group referred to as Pancrustacea. Some crustaceans (Remipedia, Cephalocarida, Branchiopoda) are more closely related to insects and the other hexapods than they are to certain other crustaceans. The 67,000 described species range in size from '' Stygotantulus stocki'' at , to the Japanese spider crab with a leg span of up to and a mass of . Like other arthropods, crustaceans have an exoskeleton, which they moult to grow. They are distinguished from other groups of arthropods, such as insects, myriapods and chelicerates, by the possession of biramous (two-parted) limbs, and by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mandible (arthropod)
250px, The mandibles of a bull ant The mandible (from la, mandibula or mandĭbŭ-lum, a jaw) of an arthropod is a pair of mouthparts used either for biting or cutting and holding food. Mandibles are often simply called jaws. Mandibles are present in the extant subphyla Myriapoda (millipedes and others), Crustacea and Hexapoda (insects etc.). These groups make up the clade Mandibulata, which is currently believed to be the sister group to the rest of arthropods, the clade Arachnomorpha (Chelicerata and Trilobita). Unlike the chelicerae of arachnids, mandibles can often be used to chew food. Mandibulates also differ by having antennae, and also by having three distinct body regions: head, thorax and abdomen. (The cephalothorax (or prosoma) of chelicerates is a fusion of head and thorax.) Insects Insect mandibles are as diverse in form as their food. For instance, grasshoppers and many other plant-eating insects have sharp-edged mandibles that move side to side. Mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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