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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 activation ... [...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 relationships of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Araneomorphae
The Araneomorphae (also called the Labidognatha) 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 of living spiders. Distinguishing characteristics Most spider species are Araneomorphae, which have fangs that face towards each other, increasing the orientations they can employ during prey capture. They have fewer book lungs (when present), and the females typically live one year. The Mygalomorphae have 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 four pairs of book lungs, and the females often live many years. Image:Atrax robustus.jpg, This ''Atrax robustus'' shows the orientation of Myglamorphae fangs. Image:Che ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pacullidae
Pacullidae is a family of araneomorph spiders first described by Eugène Simon in 1894. It was merged into Tetrablemmidae in 1958, then raised back to family status after a large phylogenetic study in 2017. Description The family Pacullidae contains three-clawed spiders with six eyes, lacking a cribellum. They resemble spiders from the family Tetrablemmidae in some respects but are much larger, always exceeding 5 mm long, have a very wrinkled (rugose) cuticle, and females do not have large membranous receptacles. Phylogeny Pacullidae falls within the Synspermiata clade, a clade of former haplogyne spiders with "synsperm" – encapsulated groups of 2–4 fused sperm cells. Within this clade, it groups with four other families, including Tetrablemmidae, but is distinct from the latter, being most closely related to Diguetidae. Together with Pholcidae, these four families are placed in the "lost trachea clade", a group of families that have lost their posterior respiratory syst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pholcus Phalangioides
''Pholcus phalangioides'', commonly known as daddy long-legs spider or long-bodied cellar spider, is a spider of the family Pholcidae. It is also known as the skull spider, since its cephalothorax resembles a human skull. This is the only spider species described by the Swiss entomologist Johann Kaspar Füssli, who first recorded it in 1775. Its common name of "daddy long-legs" should not be confused with a different arachnid group with the same common name, the harvestman (Opiliones). Females have a body length of about 8 mm while males tend to be slightly smaller. The length of the spider's legs are on average 5 or 6 times the length of its body. ''Pholcus phalangioides'' has a habit of living on the ceilings of rooms, caves, garages or cellars. This spider species is considered beneficial in parts of the world because it preys on other spiders, including species considered dangerous such as redback spiders. ''Pholcus phalangioides'' is known to be harmless to humans a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drymusidae
Drymusidae is a family of araneomorph spiders first described by Eugène Simon in 1893, and elevated to family status by Pekka T. Lehtinen in 1986. Genera , the World Spider Catalog accepts the following genera: *''Drymusa ''Drymusa'' is a genus of false violin spiders that was first described by Eugène Simon in 1892. They physically resemble violin spiders (''Loxosceles''), but their bites are not believed to be medically significant. Originally placed with t ...'' Simon, 1892 — Caribbean, Costa Rica, South America *'' Izithunzi'' Labarque, Pérez-González & Griswold, 2018 — South Africa References Araneomorphae families {{araneomorphae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trogloraptoridae
''Trogloraptor'' is a genus of large spiders found in the caves of southwestern Oregon. It is the sole genus in the family Trogloraptoridae, and includes only one species, ''Trogloraptor marchingtoni''. These spiders are predominantly yellow-brown in color with a maximum leg span of . They are remarkable for having hook-like claws on the raptorial last segments of their legs. ''Trogloraptor'' belongs to one of only three new spider families described since 1990. The specific name is in honor of the amateur cave biologist and deputy sheriff Neil Marchington. Discovery The spiders were first collected in 2010 by Geo Graening, Neil Marchington, Ron Davis and Daniel Snyder, cave conservationists from the Western Cave Conservancy. They were described in 2012 by a research team consisting of arachnologists Charles Griswold, Tracy Audisio and Joel Ledford of the California Academy of Sciences. The male holotype was recovered from the M2 cave near Grants Pass, Oregon, on July 29, 201 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrablemmidae
Tetrablemmidae, sometimes called armored spiders, is a family of tropical araneomorph spiders first described by Octavius Pickard-Cambridge in 1873. It contains 126 described species in 29 genera from southeast Asia, with a few that occur in Africa and Central and South America. Pacullidae was incorporated into this family in 1981, but was later restored as a separate family in a 2016 phylogenetic study. Most species have been collected from litter and soil, including that of epiphytes. Some live in caves and show typical adaptations of cave spiders, such as loss of eyes and weak sclerotization. Members of '' Tetrablemma'' only have four eyes, a trait in spiders only found in these and certain members of Caponiidae. Genera , the World Spider Catalog accepts the following genera: *'' Ablemma'' Roewer, 1963 — Papua New Guinea, Asia *'' Afroblemma'' Lehtinen, 1981 — Angola, Tanzania, Congo *'' Anansia'' Lehtinen, 1981 — Angola *'' Bacillemma'' Deeleman-Reinhold, 1993 — Tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sicariidae
Sicariidae is a family of six-eyed venomous spiders known for their potentially necrotic bites. The family consists of three genera and about 160 species. Well known spiders in this family include the brown recluse spider and the six-eyed sand spider. Description ''Loxosceles'', commonly known as "recluse spiders" or "violin spiders", is distributed nearly worldwide in warmer areas. ''Hexophthalma'' and '' Sicarius'', commonly known as "sand spiders" or "assassin spiders", live in the deserts of southern Africa and South to Central America, respectively. They are known for their self-burying behavior and the ability to go for long periods without food or water. All members have six eyes arranged in three groups of two (dyads). Violin spiders are usually brownish with a darker brown characteristic violin marking on the cephalothorax. They are also haplogyne, meaning the females possessing unsclerotised genitals. ''Hexophthalma'' and ''Sicarius'' resemble crab spiders and lack ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Segestriidae
Tube-dwelling spiders (Segestriidae) are a family of araneomorph spiders first described by Eugène Simon in 1893. It consists of five genera, two large and widespread, '' Segestria'' and ''Ariadna'', and three smaller genera, '' Citharoceps'', '' Gippsicola'' and '' Indoseges''. They are haplogyne spiders, related to the Dysderidae and placed in clade or superfamily Dysderoidea. Members of this family are easily recognized because their first three pairs of legs are arranged forward instead of two and they have six eyes instead of eight, arranged in a semicircle. The leg structure appears to be an adaptation for living in silken tubes. Unlike those of the atypical tarantulas, these tubes may branch and are often built in tree bark fissures, as well as under stones. Both ''Segestria'' and ''Ariadna'' live in North America, South America, Eurasia, Africa and New Zealand, though ''Ariadna'' also lives in Australia. Genera , the World Spider Catalog accepts the following gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scytodidae
Spitting spiders (Scytodidae) is a family of araneomorph spiders first described by John Blackwall in 1864. It contains over 250 species in five genera, of which ''Scytodes'' is the best-known. Description Like recluse spiders and coneweb spiders, they have six eyes arranged in three pairs and are haplogyne, meaning they have less complex female genitalia. They differ from these families in having a dome-shaped carapace and in their characteristic flecked pattern of spots. Hunting technique Scytodidae catch their prey by spitting a fluid that congeals on contact into a venomous and sticky mass. The fluid contains both venom and spider silk in liquid form, though it is produced in venom glands in the chelicerae. The venom-laced silk both immobilizes and envenoms prey such as silverfish. In high-speed footage the spiders can be observed swaying from side to side as they "spit", catching the prey in a criss-crossed "Z" pattern; it is criss-crossed because each of the chelicerae e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plectreuridae
Plectreuridae, also called plectreurid spiders, is a small spider family confined to the Southwestern United States, Mexico, and the Caribbean. Only two living genera are known—the nominate genus '' Plectreurys'' and '' Kibramoa''. In the past, the family was more widespread, with the Jurassic genus '' Eoplectreurys'' known from China, the Eocene '' Palaeoplectreurys baltica'' from Baltic amber and the Miocene '' Plectreurys pittfieldi'' from Dominican amber. These ecribellate, haplogyne spiders build haphazard webs under rocks and dead cacti. Adult males can be found wandering at night. Relatively little is known of their biology. Unlike the sicariids, scytodids, and diguetids, to which they are most closely related, they have eight eyes. In appearance females of ''Plectreurys'' resemble those of the larger species of the cribellate Filistatidae. They differ in their eye arrangement and in having the femurs on the first pair of legs bowed. Genera , the World Spider Ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Periegopidae
''Periegops'' is a genus of spiders with six eyes instead of the usual eight. It is the only genus in its family (Periegopidae) and has three described species. It was long considered to be members of Sicariidae or Segestriidae until Raymond Forster elevated them to the family level in 1995. Taxonomy ''Periegops'' was first described in 1893 by Eugene Simon from a specimen of ''P. hirsutus'' (A synonym of ''P. suterii'').Simon, E. (1893a). ''Histoire naturelle das araignées''. Paris 1, 257-488. doi:10.5962/bhl.title.51973 Description This genus of spider has only six eyes, as opposed to eight, which is typical for spiders. Body length varies from 5.9mm to 10mm depending on species and sex. Carapace is an orange colour and is darker on the anterior side. Abdomen is brown or creamy brown and usually have a chevron pattern. The family can be distinguished by the pattern of eye positions, which are in three clusters of two eyes. Species , the World Spider Catalog The World S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
