Velvet spiders Temporal range: | |
---|---|
Eresus kollari , male | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Subphylum: | Chelicerata |
Class: | Arachnida |
Order: | Araneae |
Infraorder: | Araneomorphae |
Family: | Eresidae C. L. Koch, 1845 |
Diversity | |
9 genera, 128 species | |
Velvet spiders (family Eresidae) are a small group (about 100 species in 9 genera [1] ) of spiders almost entirely limited to the Old World, with the exception of one species known from Brazil. In Europe, some are commonly called the ladybird spiders.
This family can sometimes be confused with the jumping spiders, or those in the Palpimanidae family. These spiders are usually black or brown in colour, though they can also have brighter colours as pictured. As their common name implies they can look quite smooth and velvety. [2] They usually live in silken tubes under objects, or underground, but the genus Stegodyphus, builds silken nests.
They can be distinguished from most species except the Penestomidae by their semi-rectangular carapace and clypeal hood. They can be distinguished from Penestomidae by the eye arrangement, straight anterior eye row and strongly recurved posterior eye row, with the median eyes close together. [3]
Some species are nearly eusocial, [4] lacking only a specialized caste system and a queen. They cooperate in brood rearing, unlike most other spiders except for some spitting spiders, African agelenid spiders in the genus Agelena, Monocentropus balfouri and a few others.[ citation needed ] Female velvet spiders exhibit a remarkable type of maternal care unique among arachnids. Upon the birth of her brood, the mother spider liquefies her internal organs and regurgitates this material as food. Once her capability to liquefy her insides is exhausted, the young sense this and consume the mother. [5]
Spiders of the genus Stegodyphus genus, such as Stegodyphus sarasinorum in India, are known for their elaborate and robust nests and their colony integrity.[ citation needed ]
The genus Penestomus was previously placed in Eresidae as the subfamily Penestominae, but was elevated to its own family, Penestomidae, in 2010.[ citation needed ]As of April 2019 [update] , the World Spider Catalog accepts the following genera: [1]
The Thomisidae are a family of spiders, including about 170 genera and over 2,100 species. The common name crab spider is often linked to species in this family, but is also applied loosely to many other families of spiders. Many members of this family are also known as flower spiders or flower crab spiders.
Oonopidae, also known as goblin spiders, is a family of spiders consisting of over 1,600 described species in about 113 genera worldwide, with total species diversity estimated at 2000 to 2500 species. The type genus of the family is OonopsKeyserling, 1835.
Zoropsidae, also known as false wolf spiders for their physical similarity to wolf spiders, is a family of cribellate araneomorph spiders first described by Philipp Bertkau in 1882. They can be distinguished from wolf spiders by their two rows of eyes that are more equal in size than those of Lycosidae.
Cybaeidae is a family of spiders first described by Nathan Banks in 1892. The diving bell spider or water spider Argyroneta aquatica was previously included in this family, but is now in the family Dictynidae.
Eresus, also called ladybird spiders, is a genus of velvet spiders that was first described by Charles Athanase Walckenaer in 1805. Members of the genus formerly called Eresus cinnaberinus or Eresus niger are now placed in one of three species: Eresus kollari, Eresus sandaliatus and Eresus moravicus.
Tomocyrba is a genus of Malagasy jumping spiders that was first described by Eugène Louis Simon in 1900.
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.
Orsolobidae is a six-eyed spider family with about 180 described species in thirty genera. It was first described by J. A. L. Cooke in 1965, and was raised to family status from "Dysderidae" in 1985.
Phyxelididae is a family of araneomorph spiders first described by Pekka T. Lehtinen in 1967 as a subfamily of Amaurobiidae, and later elevated to family status as a sister group of Titanoecidae.
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. As of September 2018, the following five families were included:
The Eresoidea or eresoids are a group of araneomorph spiders that have been treated as a superfamily. As usually circumscribed, the group contains three families: Eresidae, Hersiliidae and Oecobiidae. Studies and reviews based on morphology suggested the monophyly of the group; more recent gene-based studies have found the Eresidae and Oecobiidae to fall into different clades, placing doubt on the acceptability of the taxon. Some researchers have grouped Hersiliidae and Oecobiidae into the separate superfamily Oecobioidea, a conclusion supported in a 2017 study, which does not support Eresoidea.
Stegodyphus is a genus of velvet spiders that was first described by Eugène Simon in 1873. They are distributed from Africa to Europe and Asia, with one species found in Brazil. The name is derived from Ancient Greek στέγω, meaning "covered".
Loureedia is a genus of velvet spiders that was first described by J. A. Miller in 2012. As of July 2020, it contained four species: L. annulipes, L. colleni, L. lucasi and L. phoenixi. This genus of velvet spiders that live underground are named after Lou Reed, guitarist and singer for the Velvet Underground. In 2020, researchers discovered the fourth species, L. phoenixi, in Iran.
Penestomus is a genus of African araneomorph spiders in the family Penestomidae, and was first described by Eugène Louis Simon in 1902. The genus was formerly included in the family Eresidae, but was elevated to its own family in 2010. It is now considered closer to Zodariidae.
Seothyra, commonly known as the buckspoor spiders, buck spoor spiders or just spoor spiders, belong to a sand-dwelling, burrowing genus of araneomorph spiders in the family Eresidae. The 13 species are endemic to the arid, sandy flats and semistabilized red dunes of southern Africa. They are sexually dimorphic. The tiny males, which are seldom seen, imitate sugar ants or velvet ants in their appearance and habits, while the females hide in and hunt from their characteristic burrows. They are thermophilous, with males as well as females being most active on hot days.
Paradonea is a genus of African velvet spiders that was first described by R. F. Lawrence in 1968.
Nephilingis is a genus of spiders in the family Nephilidae. It was split off from the genus Nephilengys in 2006. Both genera have been called hermit spiders from the habit of staying in their retreats during the day; alternatively the name "hermit spider" may be reserved for Nephilingis, with Nephilengys species called "eunuch spiders".
Paradonea presleyi is a species of araneomorph spiders in the family Eresidae.
Stegodyphus dumicola, commonly known as the African social spider, is a species of spider of the family Eresidae, or the velvet spider family. It is native to Central and southern Africa. This spider is one of three Stegodyphus spiders that lives a social lifestyle. This spider has been studied living in large natal colonies in large, unkempt webs. Each colony is composed mainly of females, where a minority act as reproducers, and a majority remain childless and take care of the young. Males live a shorter lifespan, during which they will largely remain in the natal nest. Females are known for extreme allomaternal care, since all females – even unmated virgin ones – will take care of the young until they are eventually consumed by the brood.