Deinopis, also known as net-casting spiders, gladiator spiders and ogre-faced spiders, is a genus 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".
Etymology The name is derived from the Greek (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 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. To aid further in netting prey, the spider places white fecal spots on the surface below the net and uses them for aiming. Spiders also lack ears, but Deinopis species use hairs and receptors (slit sensillae) on their legs to distinguish sounds at a distance of up to 2 meters.
Auditory senses
Based on experiments investigating neural responses to sound, Deinopis spiders are able to detect acoustic signals over a broad range of frequencies, ranging from 100 – 10,000 Hz.
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); instead, each night, a large area of light-sensitive membrane is manufactured within the eyes, and destroyed at dawn, with the membrane being converted into vesicles which are then lysed in the inter-rhabdomeral cytoplasm.
Species , this genus included twenty species:
Deinopis amica Schiapelli & Gerschman, 1957 – Argentina, Uruguay Deinopis armaticeps Mello-Leitão, 1925 – Brazil Deinopis biaculeata Simon, 1906 – Brazil Deinopis bituberculata Franganillo, 1930 – Cuba Deinopis bucculenta Schenkel, 1953 – Venezuela Deinopis cylindracea C. L. Koch, 1846 – Colombia Deinopis diabolica Kraus, 1956 – El Salvador Deinopis fastigata Simon, 1906 – Brazil Deinopis granadensis Keyserling, 1879 – Colombia Deinopis guasca Mello-Leitão, 1943 – Brazil Deinopis guianensis Taczanowski, 1874 – French Guiana Deinopis lamia MacLeay, 1839 – Cuba, Turks & Caicos, Puerto Rico (type species) Deinopis longipes F.O. Pickard-Cambridge, 1902 – Mexico, Panama Deinopis pallida Mello-Leitão, 1939 – Brazil Deinopis pardalis Simon, 1906 – Brazil Deinopis plurituberculata Mello-Leitão, 1925 – Brazil Deinopis rodophthalma Mello-Leitão, 1939 – Brazil Deinopis seriata Simon, 1906 – Brazil Deinopis spinosa Marx, 1889 – United States, Jamaica, St. Vincent, Venezuela Deinopis tuboculata Franganillo, 1926 – Cuba
References
External links Deinopis at BugGuide Picture of Deinopis ravida