|
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] |
Caponiidae
Caponiidae is a family of ecribellate haplogyne spiders that are unusual in a number of ways. They differ from other spiders in lacking book lungs and having the posterior median spinnerets anteriorly displaced to form a transverse row with the anterior lateral spinnerets. Most species have only two eyes, which is also unusual among spiders. A few species of Caponiidae variously have four, six or eight eyes. In some species the number of eyes will increase when the spiderling changes its skin as it grows towards adulthood. Description These spiders of about are rarely noticed, but generally look like somewhat faded woodlouse hunter spiders in the genus ''Dysdera''. The carapace (cephalothorax or prosoma) is orange and the abdomen (opisthosoma) light gray. The two-eyed species have their two eyes in the anterior middle of the carapace. Eye numbers Caponiidae are unusual in the degree to which the eye number varies. In this they surpass even the family Cybaeidae in which some s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Austrochiloidea
The Austrochiloidea or austrochiloids are a group of araneomorph spiders, treated as a superfamily. The taxon contains two families of eight-eyed spiders: * Austrochilidae Zapfe, 1955 * Gradungulidae Forster, 1955 Phylogeny The monophyly of the Austrochiloidea has been supported in both morphological and molecular phylogenetic studies. The position of the clade relative to two much larger groups, Haplogynae and 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; m ..., has varied. A summary in 2005 showed the Austrochiloidea to be basal to both groups: Two studies have placed representatives of the Austrochiloidea between the two, suggesting they have more derived characters than previously supposed: References {{Taxonbar, from=Q54482 Araneomorphae Arachnid super ... [...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] |
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] |
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 boo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 releas ... [...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 spinnerets of spiders, the cribellum consists of one or more plates covered in thousands of tiny 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 epicuticle of insect prey on contact. This creates a po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diguetidae
Coneweb spiders (Diguetidae) are six-eyed haplogyne spiders that live in tangled space webs, fashioning a cone-like central retreat where they hide and lay eggs. It is a small family, containing only two genera with fifteen species and is confined to the New World, preferring deserts. Members of the genus '' Diguetia'' usually build their webs in shrubs or between cactus pads. They have the same eye arrangement as the venomous recluse spiders (family ''Sicariidae''), but none are known to be harmful to humans. Taxonomy The group was first created by F. O. Pickard-Cambridge in 1899 as the subfamily Diguetiinae of the family Scytodidae. It was raised to the rank of family by Willis J. Gertsch using the spelling "Diguetidae". Pickard-Cambridge's use of double "i" is correct according to Article 29.3 of the International Code of Zoological Nomenclature, since the name is based on the genus ''Diguetia''. In 2004, Jörg Wonderlich suggested reducing it again to a subfamily, this time ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypochilidae
Lampshade spiders, family Hypochilidae, are among the most primitive of araneomorph spiders. There are two genera and twelve species currently recognized. Like mygalomorphs, most hypochilids have two pairs of book lungs, but like araneomorphs they have intersecting fangs, with the exception of some species which have chelicerae in an angle that is neither orthognathous or labidognathous. These long-legged spiders build typical "lampshade" style webs under overhangs and in caves. In the United States the fauna is primarily associated with the Appalachian, Rocky and California Mountains. Ten of the known species are found in these ranges, all in the genus ''Hypochilus''. The genus ''Ectatosticta'' is found in China. In one analysis, the Hypochilidae are a sister clade to the Neocribellatae, which contains all other spider species in the Araneomorphae (Coddington & Levi, 1991, p. 576). A more recent study groups them with the Haplogynae. , p. 1766. Species '' Ectatosticta' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spider
Spiders ( order Araneae) are air-breathing arthropods that have eight legs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species diversity among all orders of organisms. Spiders are found worldwide on every continent except for Antarctica, and have become established in nearly every land habitat. , 50,356 spider species in 132 families have been recorded by taxonomists. However, there has been debate among scientists about how families should be classified, with over 20 different classifications proposed since 1900. Anatomically, spiders (as with all arachnids) differ from other arthropods in that the usual body segments are fused into two tagmata, the cephalothorax or prosoma, and the opisthosoma, or abdomen, and joined by a small, cylindrical pedicel, however, as there is currently neither paleontological nor embryological evidence that spiders ever had ... [...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] |
Dysderidae
Dysderidae, also known as woodlouse hunters, sowbug-eating spiders, and cell spiders, is a family of araneomorph spiders first described by Carl Ludwig Koch in 1837. They are found primarily in Eurasia, extending into North Africa with very few species occurring in South America. ''Dysdera crocata'' is introduced into many regions of the world. Dysderids have six eyes, and are haplogyne, i.e. the females lack a sclerotized epigyne. There is a substantial number of genera, but two of them, ''Dysdera'' and ''Harpactea'', account for a very large number of the species and are widespread across the family's range. One species, ''Dysdera crocata'' (the woodlouse hunter), has been transported over much of the planet together with its preferred foods—woodlice. ''Dysdera'' also feeds on beetles. These spiders have very large chelicerae, which they use to pierce the armored bodies of woodlice and beetles. There are also some reports that they have a mildly toxic venom that can cause lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
_rotated.jpg "Click for more on -> Hypochilidae")
