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Palpal
Pedipalps (commonly shortened to palps or palpi) are the secondary pair of forward appendages among 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. From the proximal end (where they are attached to the body) to the distal, they are: 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 pedipalpa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
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 (tagma (biology), tagmata), located towards the Posterior (anatomy), posterior end; see also Abdomen#Other animals, 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: see * Apophysis (plural apophyses): An outgrowth or process changing the general shape of a body part, particularly the appendages; often used in describing the male : see * Atrium (plural atria): An internal chamber at the entrance to the in female Haplogynae, haplogyne spiders B * Bidentate: Having two * Book lungs: Respiratory organs on the ventral side (underside) of the , in f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Pedipalp In Green
Pedipalps (commonly shortened to palps or palpi) are the secondary pair of forward appendages among Chelicerata, 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. From the proximal end (where they are attached to the body) to the distal, they are: the coxa, the Arthropod leg#Trochanter, trochanter, the Arthropod leg#Femur, femur, the short Glossary_of_spider_terms#patella, patella, the Glossary_of_spider_terms#tibia, tibia, and the Arthropod_leg#Tarsus, tarsus. In spiders, the coxae frequently have extensions called Glossary_of_spider_terms#maxilla , maxillae or gnathobases, which function as mouth parts with or without some contribution from the coxae of the anterior arthropod leg, legs. The limbs themselves may be simple tactile organs outwardly resembling the legs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Spider
Spiders (order (biology), order Araneae) are air-breathing arthropods that have eight limbs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude spider silk, silk. They are the largest order of arachnids and rank seventh in total species diversity among all Order (biology), orders of organisms. Spiders are found worldwide on every continent except Antarctica, and have become established in nearly every land habitat. , 53,034 spider species in 136 Family (biology), families have been recorded by Taxonomy (biology), taxonomists. However, there has been debate among scientists about how families should be classified, with over 20 different classifications proposed since 1900. Anatomy, Anatomically, spiders (as with all arachnids) differ from other arthropods in that the usual body segmentation (biology), segments are fused into two Tagma (biology), tagmata, the cephalothorax or prosoma, and the opisthosoma, or abdomen, and joined by a small, cylindr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Uropygi
Uropygi is an arachnid order comprising invertebrates commonly known as whip scorpions or vinegaroons (also spelled vinegarroons and vinegarones). They are often called uropygids. The name "whip scorpion" refers to their resemblance to scorpion, true scorpions and possession of a whiplike tail, and "vinegaroon" refers to their ability when attacked to discharge an offensive, vinegar-smelling liquid, which contains acetic acid. The order may also be called Thelyphonida. Both names, Uropygi and Thelyphonida, may be used either in a narrow sense for the order of whip scorpions, or in a broad sense which includes the order Schizomida. Taxonomy Carl Linnaeus first described a whip scorpion in 1758, although he did not distinguish it from what are now regarded as different kinds of arachnid, calling it ''Phalangium caudatum''. ''Phalangium'' is now used as a name for a genus of harvestmen (Opiliones). In 1802, Pierre André Latreille was the first to use a genus name solely for whip s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Sea Spider
Sea spiders are marine arthropods of the class (biology), class Pycnogonida, hence they are also called pycnogonids (; named after ''Pycnogonum'', the type genus; with the suffix '). The class includes the only now-living order (biology), order Pantopoda ( ‘all feet’), alongside a few fossil species which could trace back to the early or mid Paleozoic. They are cosmopolitan distribution, cosmopolitan, found in oceans around the world. The over 1,300 known species have leg spans ranging from to over . Most are toward the smaller end of this range in relatively shallow depths; however, they can grow to be quite large in Antarctic and deep-sea gigantism, deep waters. Despite their name and brief resemblance, "sea spiders" are not spiders, nor even arachnids. While some literature around the 2000s suggests they may be a sister group to all other living arthropods, their traditional classification as a member of chelicerates alongside Xiphosura, horseshoe crabs and arachnids has r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
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 Americas ('' Cryptocellus'' and '' Pseudocellus'') from Brazil to southern Texas, where they inhabit either leaf-litter or caves. As of 2022, 103 extant species of ricinuleids have been described worldwide, all in the single family Ricinoididae. 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, Ricinulei has a fossil-record spanning over 300 million years, including fossils from the Late Carboniferous of Euramerica and the Cretaceous Burmese amber. Anatomy and physiology 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 Mitche ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
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 because they prey on Tineola bisselliella, clothes moth larvae, Dermestidae, carpet beetle larvae, Psocoptera, booklice, ants, mites, and small Diptera, flies. They are common in many environments, but they are rarely noticed due to their small size. When people see pseudoscorpions, especially indoors, they often mistake them 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, DepartmentEntomol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Xiphosura
Xiphosura (; , in reference to its sword-like telson) is an order of arthropods related to arachnids. They are more commonly known as horseshoe crabs (a name applied more specifically to the only extant family, Horseshoe crab, Limulidae). They first appeared in the Hirnantian (Late Ordovician). Currently, there are only four living species. Xiphosura contains one suborder, Xiphosurida, and several stem-genera. The group has hardly changed in appearance in hundreds of millions of years; the modern horseshoe crabs look almost identical to prehistoric genera and are considered to be living fossils. The most notable difference between ancient and modern forms is that the abdominal segments in present species are fused into a single unit in adults. Xiphosura were historically placed in the class Merostomata, although this term was intended to encompass also the Eurypterida, eurypterids, whence it denoted what is now thought to be an unnatural (paraphyletic) group (although this is a gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Primitive (biology)
In phylogenetics, a primitive (or ancestral) character, trait, or feature of a lineage or taxon is one that is inherited from the common ancestor of a clade (or clade group) and has undergone little change since. Conversely, a trait that appears ''within'' the clade group (that is, is present in any subgroup within the clade but not all) is called advanced or derived. A clade is a group of organisms that consists of a common ancestor and all its lineal descendants. A primitive trait is the original condition of that trait in the common ancestor; advanced indicates a notable change from the original condition. These terms in biology contain no judgement about the sophistication, superiority, value or adaptiveness of the named trait. "Primitive" in biology means only that the character appeared first in the common ancestor of a clade group and has been passed on largely intact to more recent members of the clade. "Advanced" means the character has evolved within a later subgroup ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Antennae (biology)
An antenna (plural: antennae) is one of a pair of appendages used for Sensory system, sensing in arthropods. Antennae are sometimes referred to as ''feelers''. Antennae are connected to the first one or two Segmentation (biology), 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 tactition, touch, air motion, heat, vibration (sound), and especially insect olfaction, smell or gustation, taste. Antennae are sometimes modified for other purposes, such as mating, brooding, swimming, and even anchoring the arthropod to a substrate (biology), 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 i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
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 expre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Raptorial
In biology (specifically the anatomy of arthropods), the term ''raptorial'' implies much the same as ''predatory'' but most often refers to modifications of an arthropod leg, 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 Segmentation (biology), segments (''see illustration''). This is distinctly different from the grasping mechanism of a structure such as a scorpion's claw (a "Chela (organ), chela") in which one of the opposing surfaces is an articulated digit, and not a leg segment. While this is most widely known in Mantodea, 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, mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
