''Deinopis'', also known as net-casting spiders, gladiator spiders and ogre-faced spiders, is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of net-casting spiders that was first described by W. S. MacLeay in 1839. Its distribution is widely tropical and subtropical. They catch their prey using a specially spun "net". The name is derived from the

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(''deinos''), meaning "fearful", and ''opis'', meaning "appearance", referring to their ogre-like faces. The spelling "''Dinopis''" is also found, but is regarded as an "unjustified emendation".

Net-casting

Spiders in the genus ''Deinopis'' catch their prey in an unusual fashion. They first spin a small upright rectangular

cribellate 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 o ...

web. This is then detached from its supporting threads and held horizontally above the ground by the spider's long front two pairs of legs while the spider hangs almost vertically. Passing prey is then captured by dropping the "net" over it.

Eyes

The two posterior median eyes are enlarged and forward-facing. These eyes have a wide field of view and are able to gather available light more efficiently than the eyes of cats and owls, and are 2000 times more sensitive to light than human photoreceptors. This is despite the fact that they lack a reflective layer (

tapetum lucidum The ''tapetum lucidum'' ( ; ; ) is a layer of tissue in the eye of many vertebrates and some other animals. Lying immediately behind the retina, it is a retroreflector. It reflects visible light back through the retina, increasing the light a ...

); instead, each night, a large area of light-sensitive membrane is manufactured within the eyes, and since arachnid eyes do not have irises, it is rapidly destroyed again at dawn. To aid further in netting prey, the spider places white fecal spots on the surface below the net and uses them for aiming. The spiders also lack ears and use hairs and receptors on their legs to distinguish sounds at a distance of up to 2 meters.

Species

it contains twenty species: *'' D. amica'' Schiapelli & Gerschman, 1957 – Argentina, Uruguay *'' D. armaticeps'' Mello-Leitão, 1925 – Brazil *'' D. biaculeata''

Simon Simon may refer to: People * Simon (given name), including a list of people and fictional characters with the given name Simon * Simon (surname), including a list of people with the surname Simon * Eugène Simon, French naturalist and the genus ...

, 1906 – Brazil *'' D. bituberculata'' Franganillo, 1930 – Cuba *'' D. bucculenta'' Schenkel, 1953 – Venezuela *'' D. cylindracea'' C. L. Koch, 1846 – Colombia *'' D. diabolica'' Kraus, 1956 – El Salvador *'' D. fastigata'' Simon, 1906 – Brazil *'' D. granadensis'' Keyserling, 1879 – Colombia *'' D. guasca'' Mello-Leitão, 1943 – Brazil *'' D. guianensis'' Taczanowski, 1874 – French Guiana *'' D. lamia'' MacLeay, 1839 ( type) – Cuba, Puerto Rico *'' D. longipes'' F. O. Pickard-Cambridge, 1902 – Mexico to Panama *'' D. pallida'' Mello-Leitão, 1939 – Brazil *'' D. pardalis'' Simon, 1906 – Brazil *'' D. plurituberculata'' Mello-Leitão, 1925 – Brazil *'' D. rodophthalma'' Mello-Leitão, 1939 – Brazil *'' D. seriata'' Simon, 1906 – Brazil *'' D. spinosa''

Marx Karl Heinrich Marx (; 5 May 1818 – 14 March 1883) was a German philosopher, economist, historian, sociologist, political theorist, journalist, critic of political economy, and socialist revolutionary. His best-known titles are the 1848 ...

, 1889 – USA, St. Vincent, Venezuela *'' D. tuboculata'' Franganillo, 1926 – Cuba

References

External links

Deinopis
at

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Video of Gladiator spider constructing the net and catching its prey

{{Taxonbar, from=Q2704272 Araneomorphae genera Deinopidae