| Dwarf sheet spiders Temporal range: | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Subphylum: | Chelicerata |
| Class: | Arachnida |
| Order: | Araneae |
| Infraorder: | Araneomorphae |
| Family: | Hahniidae Bertkau, 1878 |
| Diversity | |
| 29 genera, 240 species | |
 | |
Dwarf sheet spiders (Hahniidae) is a family of araneomorph spiders, first described by Philipp Bertkau in 1878. [1]
Their bodies are about 2 millimetres (0.079 in) long, and they build extremely delicate webs in the form of a sheet that does not lead to a retreat. The silk used in these webs is so fine that they are difficult to spot unless they are coated with dew. They are characterized by the arrangement of their six spinnerets in a transverse row. The last segment of the outer spinnerets is quite long and stands out above all the others. [2] They greatly favor locations near water or near moss, and are often found in leaf litter and detritus or on the leaves of shrubs and trees. [2]
Hahniidae are a worldwide family. The genera of the Northern Hemisphere and Africa tend to differ in their genital structures from those of the Southern Hemisphere. Very few species have been described from southeast Asia, although quite a number seem to be yet undescribed. [2]
The family is named after the type genus Hahnia , which is dedicated to German zoologist Carl Wilhelm Hahn. [1]
As of November 2024 [update] , the World Spider Catalog accepts the following genera: [3]
Wolf spiders are members of the family Lycosidae, named for their robust and agile hunting skills and excellent eyesight. They live mostly in solitude, hunt alone, and usually do not spin webs. Some are opportunistic hunters, pouncing upon prey as they find it or chasing it over short distances; others wait for passing prey in or near the mouth of a burrow. Wolf spiders resemble nursery web spiders, but wolf spiders carry their egg sacs by attaching them to their spinnerets, while the Pisauridae carry their egg sacs with their chelicerae and pedipalps. Two of the wolf spider's eight eyes are large and prominent; this distinguishes them from nursery web spiders, whose eyes are all of roughly equal size. This can also help distinguish them from the similar-looking grass spiders.
Miturgidae is a family of araneomorph spiders that includes nearly 170 species in 29 genera worldwide. First described by Eugène Simon in 1886, it has been substantially revised, and includes the previous family Zoridae as a synonym, and excludes the family Xenoctenidae. Several genera have also been removed, such as the large genus Cheiracanthium, which was transferred to the Cheiracanthiidae.
Ground spiders comprise Gnaphosidae, the seventh largest spider family with over 2,000 described species in over 100 genera distributed worldwide. There are 105 species known to central Europe, and common genera include Gnaphosa, Drassodes, Micaria, Cesonia, Zelotes and many others. They are closely related to Clubionidae. At present, no ground spiders are known to be seriously venomous to humans.
Anyphaenidae is a family of araneomorph spiders, sometimes called anyphaenid sac spiders. They are distinguished from the sac spiders of the family Clubionidae and other spiders by having the abdominal spiracle placed one third to one half of the way anterior to the spinnerets toward the epigastric furrow on the underside of the abdomen. In most spiders the spiracle is just anterior to the spinnerets.
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.
Linyphiidae, spiders commonly known as sheet weavers, or money spiders is a family of very small spiders comprising 4706 described species in 620 genera worldwide. This makes Linyphiidae the second largest family of spiders after the Salticidae. The family is poorly understood due to their small body size and wide distribution; new genera and species are still being discovered throughout the world. The newest such genus is Himalafurca from Nepal, formally described in April 2021 by Tanasevitch. Since it is so difficult to identify such tiny spiders, there are regular changes in taxonomy as species are combined or divided.
Corinnidae is a family of araneomorph spiders, sometimes called corinnid sac spiders. The family, like other "clubionoid" families, has a confusing taxonomic history. Once it was a part of the large catch-all taxon Clubionidae, now very much smaller. The original members of the family are apparently similar only in that they have eight eyes arranged in two rows, conical anterior spinnerets that touch and are generally wandering predators that build silken retreats, or sacs, usually on plant terminals, between leaves, under bark or under rocks.
Wandering spiders (Ctenidae) are a family of spiders that includes the Brazilian wandering spiders. These spiders have a distinctive longitudinal groove on the top-rear of their oval carapace similar to those of the Amaurobiidae. They are highly defensive and venomous nocturnal hunters. Wandering spiders are known to hunt large prey, for example hylid species Dendropsophus branneri. Despite their notoriety for being dangerous, only a few members of Phoneutria have venom known to be hazardous to humans, but the venoms of this family are poorly known, so all larger ctenids should be treated with caution.
Amaurobiidae is a family of three-clawed cribellate or ecribellate spiders found in crevices and hollows or under stones where they build retreats, and are often collected in pitfall traps. Unlidded burrows are sometimes quite obvious in crusty, loamy soil. They are difficult to distinguish from related spiders in other families, especially Agelenidae, Desidae and Amphinectidae. Their intra- and interfamilial relationships are contentious. According to the World Spider Catalog, 2023, the family Amaurobiidae includes 286 species in 50 genera.
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.
Dictynidae is a family of cribellate, hackled band-producing spiders first described by Octavius Pickard-Cambridge in 1871. Most build irregular webs on or near the ground, creating a tangle of silken fibers among several branches or stems of one plant.
Telemidae, also known as long-legged cave spiders, is a family of small haplogyne spiders. Most are cave dwelling spiders with six eyes, though some do not have any eyes at all. There are about 104 described species in sixteen genera.
Linothele is a genus of curtain web spiders that was first described by Ferdinand Karsch in 1879. All but one of the described species are from South America. The exception is L. septentrionalis from the far-away Bahamas, although it has certain features that suggest it may belong in another genus. Additionally, an undescribed species of Linothele is known from Panama.
