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Entelegynae
The Entelegynae or entelegynes are a subgroup of araneomorph spiders, the largest of the two main groups into which the araneomorphs were traditionally divided. Females have a genital plate ( epigynum) and a "flow through" fertilization system; males have complex palpal bulbs. Molecular phylogenetic studies have supported the monophyly of Entelegynae (whereas the other traditional subgroup, the Haplogynae, has been shown not to be monophyletic). The clade contains both cribellate and ecribellate spiders. Characterization The Entelegynae are characterized primarily by the nature of the female genital system. The ancestral ( plesiomorphic) system is found in non-entelegyne spiders, where there is a single external genital opening in the female's abdomen. One or more males inject sperm from their palpal bulbs via this opening; the sperm is usually stored in special spermathecae (absent in some spiders, e.g. '' Pholcus''). When eggs are released from the ovaries, sperm is also r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haplogynae
The Haplogynae or haplogynes are one of the two main groups into which araneomorph spiders have traditionally been divided, the other being the Entelegynae. Morphological phylogenetic studies suggested that the Haplogynae formed a clade; more recent molecular phylogenetic studies refute this, although many of the ecribellate haplogynes do appear to form a clade, Synspermiata. Unlike the Entelegynae, haplogynes lack hardened (sclerotized) female genitalia ( epigynes). Most of the species within this group have six eyes, as opposed to most other spiders. Spiders in the genus '' Tetrablemma'' ( Tetrablemmidae) have only four eyes, as do some members of the family Caponiidae; caponiids may even have only two eyes. However, spiders in the family Plectreuridae have the normal eight eyes. Phylogeny The Haplogynae are one of the two major groups into which araneomorph spiders were traditionally divided, the other being the Entelegynae. In 2005, Coddington summarized the relatio ... [...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] |
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] |
Araneomorphae
The Araneomorphae (also called the Labidognatha or "true spiders") are an infraorder of spiders. They are distinguishable by chelicerae (fangs) that point diagonally forward and cross in a pinching action, in contrast to the Mygalomorphae (tarantulas and their close kin), where they point straight down. Araneomorphs comprise the vast majority (about 93%) of living spiders. Distinguishing characteristics Most spider species are Araneomorphae, which have chelicerae, fangs that face towards each other, increasing the orientations that they can employ during prey-capture. They have fewer book lungs (when present) – usually one pair – and the females typically live one year. The Mygalomorphae have chelicerae, fangs that face towards the ground, and which are parallel to the long axis of the spider's body, thus they have only one orientation they can employ during prey capture. They have two pairs of book lungs, and the females often live many years. Image:Cheiracanthium pun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cribellum
Cribellum literally means "little sieve", and in biology the term generally applies to anatomical structures in the form of tiny perforated plates. In certain groups of diatoms it refers to microscopically punctured regions of the frustule, or outer layer. In certain groups of spider species, so-called cribellate spiders, the cribellum is a silk spinning organ. Unlike the usual Spinneret (spider), spinnerets of spiders, the cribellum consists of one or more plates covered in thousands of tiny Spinneret, spigots, tiny holes that hardly project from the surface, in contrast to the elongated spigots that project from spinnerets. These minute spigots produce extremely fine fibers, merely tens of nanometres thick, which are combed out by the spider's calamistrum, producing silk with a woolly texture. The fibers are so small in diameter that they are strongly subject to Van der Waals forces. In addition, the fibres have a surface that absorbs waxes from the Arthropod_cuticle#Morph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palpimanoidea
The Palpimanoidea or palpimanoids, also known as assassin spiders, are a group of araneomorph spiders, originally treated as a superfamily. As with many such groups, its circumscription has varied. , the following five families were included: * Archaeidae * Huttoniidae * Mecysmaucheniidae * Palpimanidae * Stenochilidae Many palpimanoids specialize in preying on other spiders, hence the name "assassin spiders". They have various adaptations for catching prey, including enlarged spade-like front legs, and heads raised up on a "neck" with long chelicerae ("jaws"). Fossils suggest that the group was once widespread, but most species are now found in the Southern Hemisphere. Morphological studies support the monophyly of the group, although molecular studies have produced different results. Description Many palpimanoids, particularly members of the families Archaeidae, Huttoniidae and Stenochilidae, specialize in preying on other spiders, hence the description "assassin spider ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hersiliidae
Hersiliidae is a tropical and subtropical family of spiders first described by Tamerlan Thorell in 1869, which are commonly known as tree trunk spiders. They have two prominent spinnerets that are almost as long as their abdomen, earning them another nickname, the "two-tailed spiders". They range in size from long. Rather than using a web that captures prey directly, they lay a light coating of threads over an area of tree bark and wait for an insect to stray onto the patch. When this happens, they encircle their spinnerets around their prey while casting silk on it. When the insect is immobilized, they can bite it through the shroud. Diversity Hersiliidae is an entelegyne family (characterized primarily by the nature of the female genital system), and together with the family Oecobiidae traditionally formed the superfamily Oecobioidea. The family consists of about 206 species divided into sixteen genera. It has a global distribution in tropical and subtropical regions, with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Filistatidae
Crevice weaver spiders (Filistatidae) comprise cribellate spiders with features that have been regarded as " primitive" for araneomorph spiders. They are weavers of funnel or tube webs. The family contains 18 genera and more than 120 described species worldwide. One of the most abundant members of this family in the Americas is the southern house spider (''Kukulcania hibernalis''). Named after the fierce Meso-American god Kukulkan, the females are large (up to nearly 20 mm) dark-colored spiders and males are light brown, smaller (about 10 mm), but more long-legged and with palps that are held together in front of their carapaces like the horn of a unicorn. The males also have a darker streak on the center of the dorsal carapace that causes them to be often mistaken for brown recluse spiders. The tiny members of the genus ''Filistatinella'' are like miniature versions of ''Kukulcania''. The nominate genus ''Filistata'' is Afro-Eurasian in distribution. In many older b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leptonetidae
Leptonetidae is a family of small spiders adapted to live in dark and moist places such as caves. The family is relatively primitive having diverged around the Middle Jurassic period. They were first described by Eugène Simon in 1890. Distinguishing characteristics Leptonetids are small, with most falling between 2 and 5mm in total length. They are generally pale in color and feature a greenish or bluish shine due to microscopic texture on the cuticle of their exoskeleton. Those species which have retained their eyes, have 6 eyes set in a distinctive pattern, with posterior pair set back from the others. If a spider from this family looses a leg, it usually separates between the patella and tibia rather than at the coxa/trochanter joint. Habitat Many live in caves or in leaf litter around the Mediterranean, and in Eurasia, Japan and southern North America. Genera , the World Spider Catalog The World Spider Catalog (WSC) is an online searchable database concerned with s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gradungulidae
Gradungulidae, also known as large-clawed spiders, is a spider family endemic to Australia and New Zealand. They are medium to large-sized haplogyne spiders with three claws and two pairs of book-lungs similar to Mygalomorphae. Some species build extensive webs with an upper retreat tangle and connecting threads to scaffolding. This supports the ladder-like catching platform that is glued to the ground. '' Hickmania'', ''Progradungula'' (a large spider with long legs like ''Hickmania'',), and ''Macrogradungula'' are the only cribellate genera of the family. Species '' Gradungula'' Gertsch, 1958 * '' Gradungula sorenseni'' Forster, 1955 — New Zealand '' Hickmania'' Forster, 1955 * '' Hickmania troglodytes'' (Higgins & Petterd, 1883) — Tasmania '' Kaiya'' Gray, 1987 * '' Kaiya bemboka'' Gray, 1987 — New South Wales * '' Kaiya brindabella'' (Moran, 1985) — Australian Capital Territory * '' Kaiya parnabyi'' Gray, 1987 — Victoria * '' Kaiya terama'' Gray, 1987 (type spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pholcus
''Pholcus'' is a genus of spiders of long-bodied cellar spider and allies in the family Pholcidae, with 375 described species as of January 2023. It includes the cellar spider '' P. phalangioides'', often called the "daddy longlegs". This may cause confusion because the name "daddy longlegs" is also applied to two other unrelated arthropods: the harvestman and the crane fly. Description ''Pholcus'', like Pholcidae in general, have extremely long and thin legs. The genus can be distinguished from other pholcid genera by its large size (body length >4 mm), eight eyes, evenly domed prosoma (lacking a median furrow or pit) and cylindrical opisthosoma (longer than it is high). Habitat In the wild, ''Pholcus'' live in environments such as caves, under rocks, forest shrubs and deep limestone cracks. Synanthropic species such as ''P. phalangioides'' live in and around buildings and other disturbed habitats. Species * '' Pholcus abstrusus'' Yao & Li, 2012 — China * '' Pholcu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synspermiata
Synspermiata is a clade of araneomorph spiders, comprising most of the former " haplogynes". They are united by having simpler genitalia than other araneomorph spiders, lacking a cribellum, and sharing an evolutionary history of synspermia – a particular way in which spermatozoa are grouped together when transferred to the female. Synspermia Spermatozoa are produced in a multi-step process. A primary spermatocyte with the full diploid number of chromosomes divides to form two secondary spermatocytes which are haploid, i.e., each has half the diploid number of chromosomes. Each secondary spermatocyte then divides to produce two spermatids which undergo further development to form spermatozoa. In synspermia, two or more spermatids from the same spermatocyte fuse together and are enclosed in an envelope, forming a "capsule". This contrasts with cleistospermia, where the capsules enclose individual spermatozoa. After transfer to the female in either form, decapsulation and activa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
