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Entelegyne
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 ... [...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 ( tagmata), located towards the posterior end; see also 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 → Apophysis (plural apophyses): An outgrowth or process changing the general shape of a body part, particularly the appendages; often used in describing the male → Atrium (plural atria): An internal chamber at the entrance to the in female haplogyne spiders B Bidentate: Having two Book lungs: Respiratory organs on the ventral side (underside) of the , in front of the , opening through narrow slits; see also Book lungs Branchial operculum â ... [...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] |
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, wit ... [...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] |
Araneidae
Orb-weaver spiders are members of the spider family Araneidae. They are the most common group of builders of spiral wheel-shaped webs often found in gardens, fields, and forests. The English word "orb" can mean "circular", hence the English name of the group. Araneids have eight similar eyes, hairy or spiny legs, and no stridulating organs. The family has a cosmopolitan distribution, including many well-known large or brightly colored garden spiders. With 3,108 species in 186 genera worldwide, the Araneidae comprise the third-largest family of spiders (behind the Salticidae and Linyphiidae). Araneid webs are constructed in a stereotypical fashion, where a framework of nonsticky silk is built up before the spider adds a final spiral of silk covered in sticky droplets. Orb webs are also produced by members of other spider families. The long-jawed orb weavers (Tetragnathidae) were formerly included in the Araneidae; they are closely related, being part of the superfamily Araneo ... [...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] |
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] |
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. ''Progradungula'', a large spider with long legs like '' Hickmania'', and ''Macrogradungula'' are the only cribellate genera of the family. Species '' Gradungula'' Forster, 1955 * ''Gradungula sorenseni'' Forster, 1955 — New Zealand '' 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 species) — New South Wales ''Macrogradungula'' Gray, 1987 * ''Macrogradungula moonya'' Gray, 1987 — Queensland '' Pian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Austrochilidae
Austrochilidae is a small spider family with nine species in two genera. ''Austrochilus'' and ''Thaida'' are endemic to the Andean forest of central and southern Chile and adjacent Argentina. Taxonomy , two genera are placed in the family Austrochilidae: ''Austrochilus'' and ''Thaida'', found in Chile and Argentina. The taxonomic placement of these genera has varied. In 1968, Lehtinen synonymized ''Austrochilus'' and ''Thaida'' under the latter name, placing the genus in a family he called "Thaididae". However, the family name "Thaididae" is preoccupied, being first used for a family of gastropods in 1887. A single family was accepted by Forster ''et al''. in 1987, under the name "Austrochilidae". Molecular phylogenetic studies agree in placing the two genera as basal members of the Araneomorphae, although the precise details and the family placement are not yet agreed. Phylogeny One hypothesis for the phylogeny of the genera placed in the family is shown below (Austrochilidae g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plesiomorphy
In phylogenetics, a plesiomorphy ("near form") and symplesiomorphy are synonyms for an ancestral character shared by all members of a clade, which does not distinguish the clade from other clades. Plesiomorphy, symplesiomorphy, apomorphy, and synapomorphy, all mean a trait shared between species because they share an ancestral species. Apomorphic and synapomorphic characteristics convey much information about evolutionary clades and can be used to define taxa. However, plesiomorphic and symplesiomorphic characteristics cannot. The term ''symplesiomorphy'' was introduced in 1950 by German entomologist Willi Hennig. Examples A backbone is a plesiomorphic trait shared by birds and mammals, and does not help in placing an animal in one or the other of these two clades. Birds and mammals share this trait because both clades are descended from the same far distant ancestor. Other clades, e.g. snakes, lizards, turtles, fish, frogs, all have backbones and none are either birds n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leptonetidae
Leptonetidae is a relatively primitive family of spiders first described by Eugène Simon in 1890. It is made up of tiny haplogyne spiders, meaning they lack the hardened external female genitalia. Their six eyes are arranged in a semicircle of four in front and two behind. Many live in caves or in leaf litter around the Mediterranean, and in Eurasia, Japan and southern North America. Genera , the World Spider Catalog accepted the following genera: *'' Appaleptoneta'' Platnick, 1986 — United States *'' Barusia'' KratochvÃl, 1978 — Montenegro, Croatia, Greece *'' Calileptoneta'' Platnick, 1986 — United States *'' Cataleptoneta'' Denis, 1955 — Asia, Europe *'' Chisoneta'' Ledford & Griswold, 2011 — United States, Mexico *'' Falcileptoneta'' Komatsu, 1970 — Japan, Korea *'' Jingneta'' Wang & Li, 2020 *'' Leptoneta'' Simon, 1872 — Europe, Asia, Algeria *'' Leptonetela'' KratochvÃl, 1978 — Greece, Asia *'' Longileptoneta'' Seo, 2015 — Korea *'' Masirana'' Kishida, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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