Velvet spiders (family Eresidae) are a small group (about 130

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

in 9

genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...

) of spiders almost entirely limited to the

Old World The "Old World" is a term for Afro-Eurasia that originated in Europe , after Europeans became aware of the existence of the Americas. It is used to contrast the continents of Africa, Europe, and Asia, which were previously thought of by the ...

, with exception of a few species known from Brazil. In Europe some are commonly called the ladybird spiders

Description

This family can sometimes be confused with the

jumping spiders Jumping spiders are a group of spiders that constitute the family Salticidae. As of 2019, this family contained over 600 described genera and over 6,000 described species, making it the largest family of spiders at 13% of all species. Jumping spi ...

, or those in the

Palpimanidae Palpimanidae, also known as palp-footed spiders, is a family of araneomorph spiders first described by Tamerlan Thorell in 1890. They are widely distributed throughout the tropical and subtropical regions of the world, the Mediterranean and one in ...

family. These spiders are usually black or brown in color, thought they can also have brighter colors as pictured. As their common name implies they can look quite smooth and velvety. They usually live in silken tubes under objects, or underground, but the genus ''

Stegodyphus ''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 (''S. manaus'') found in Brazil. The name is derived from Ancient Greek ('' st ...

,'' builds silken nests.

Identification

They can be distinguished from most species except the

Penestomidae ''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 i ...

by their semi rectangular

carapace A carapace is a Dorsum (biology), dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tor ...

and clypeal hood. Thought the can be distinguished from

by the eye arrangement, straight anterior eye row and strongly recurved posterior eye row, with the median eyes close together. Adonea eye group

Social Behavior

Some species are nearly

eusocial Eusociality (from Greek εὖ ''eu'' "good" and social), the highest level of organization of sociality, is defined by the following characteristics: cooperative brood care (including care of offspring from other individuals), overlapping generat ...

, lacking only a specialized caste system and a queen. They cooperate in brood rearing, unlike most other spiders except for some African agelenid spiders in the genus ''

Agelena Agelena is a genus of agelenid spiders first described by Charles Athanase Walckenaer in 1805. Sometimes referred to as Eurasian grass spiders, they trap their prey by weaving entangling non-sticky funnel webs. They are limited to the Old world, ...

Monocentropus balfouri ''Monocentropus balfouri'' is a tarantula in the ''Monocentropus'' genus, it was first described by Reginald Innes Pocock in 1897. This tarantula is also called Socotra Island Blue Baboon Tarantula, usually shortened to Blue Baboon Tarantula. Thi ...

'' and a few others. 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.Rachel Nuwer, Scientific American, October 2015. Spiders of the genus ''Stegodyphus'' genus, such as ''

Stegodyphus sarasinorum ''Stegodyphus sarasinorum,'' also known as the Indian cooperative spider, is a species of velvet spider of the family Eresidae. It is native to India, Sri Lanka, Nepal, and Myanmar. This spider is a social spider that exhibits communal predation ...

'' in India, are known for their elaborate and robust nests and their colony integrity.

Genera

The genus ''Penestomus'' was previously placed in Eresidae as the subfamily Penestominae, but was elevated to its own family,

, in 2010. , the

World Spider Catalog The World Spider Catalog (WSC) is an online searchable database concerned with spider taxonomy. It aims to list all accepted families, genera and species, as well as provide access to the related taxonomic literature. The WSC began as a series of ...

accepts the following genera: *''

Adonea ''Adonea'' is a genus of velvet spiders that was first described by Eugène Simon Eugène Louis Simon (; 30 April 1848 – 17 November 1924) was a French naturalist who worked particularly on insects and spiders, but also on birds and p ...

'' Simon, 1873 — Portugal, Algeria, Israel *''

Dorceus ''Dorceus'' is a genus of velvet spiders that was first described by C. L. Koch in 1846. Species it contains five species: *'' Dorceus albolunulatus'' (Simon Simon may refer to: People * Simon (given name), including a list of people and ...

'' C. L. Koch, 1846 — Africa, Asia *''

Dresserus ''Dresserus'' is a genus of African velvet spiders that was first described by Eugène Simon in 1876. Species it contains twenty-four species: *'' Dresserus aethiopicus'' Simon, 1909 – Ethiopia *'' Dresserus angusticeps'' Purcell, 1904 – S ...

'' Simon, 1876 — Africa *''

Eresus ''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 ...

'' Walckenaer, 1805 — Africa, Asia, Europe *''

Gandanameno ''Gandanameno'' is a genus of African velvet spiders that was first described by Pekka T. Lehtinen in 1967. Species it contains five species: *'' Gandanameno echinata'' (Purcell Henry Purcell (, rare: September 1659 – 21 November 169 ...

'' Lehtinen, 1967 — Namibia, South Africa, Malawi *''

Loureedia ''Loureedia'' is a genus of velvet spiders that was first described by J. A. Miller in 2012. , it contained four species: '' L. annulipes'', ''L. colleni'', ''L. lucasi'' and ''L. phoenixi''. This genus of velvet spiders that ...

'' Miller, Griswold, Scharff, Řezáč, Szűts & Marhabaie, 2012 — Africa, Asia *''

Paradonea ''Paradonea'' is a genus of African velvet spiders that was first described by R. F. Lawrence in 1968. Species it contains five species: *'' Paradonea parva'' (Tucker, 1920) – Namibia, Botswana, South Africa *'' Paradonea presleyi'' Miller, ...

'' Lawrence, 1968 — Namibia, Botswana, South Africa *''

Seothyra ''Seothyra'', commonly known as the buckspoor spiders, buck spoor spiders or just spoor spiders, belong to a sand-dwelling, burrowing genus of Araneomorphae, araneomorph spiders in the family Eresidae. The 13 species are endemic to the arid, sa ...

'' Purcell, 1903 — Africa *''

'' Simon, 1873 — Africa, Asia, Brazil

References

* Lehtinen, P.T. (1967): Classification of the cribellate spiders and some allied families, with notes on the evolution of the suborder Araneomorpha. ''Ann. Zool. Fenn.'' 4: 199-468. * Dippenaar-Schoeman, A.S. (1989): The African species of the subfamily Penestominae (Araneae: Eresidae): with description of two new species. ''Phytophylactica'' 21: 131-134.

External links