Deinopidae

{{Short description|Family of spiders}}

{{Automatic taxobox

| fossil_range = {{Fossil range|Cretaceous|present}}

| image = Deinopis-and-web-taiwan.jpg

| image_caption = Deinopis sp. with web

| taxon = Deinopidae

| authority = C. L. Koch, 1850

| range_map = Distribution.deinopidae.1.png

| diversity = 3 genera, 67 species

| subdivision_ranks = Genera

| subdivision = {{linked genus list

|Asianopis|Lin & Li, 2020

|Deinopis|MacLeay, 1839

|Menneus|Simon, 1876}}

}}

Deinopidae, also known as net casting spiders, is a family of cribellate{{cite journal| last1=Coddington| first1=J.A.| last2=Levi| first2=H.W.| year=1991| title=Systematics and Evolution of Spiders (Araneae)| journal=Annu. Rev. Ecol. Syst.| volume=22| pages=565–592| doi=10.1146/annurev.es.22.110191.003025}} spiders first described by Carl Ludwig Koch in 1850.{{cite book| last=Koch| first=C. L.| year=1850| title=Übersicht des Arachnidensystems|doi=10.5962/bhl.title.39561| url=https://www.biodiversitylibrary.org/bibliography/39561}} It consists of stick-like elongated spiders that catch prey by stretching a web across their front legs before propelling themselves forward. These unusual webs will stretch two or three times their relaxed size, entangling any prey that touch them. The posterior median eyes have excellent night vision, allowing them to cast nets accurately in low-light conditions. These eyes are larger than the others, and sometimes makes these spiders appear to only have two eyes. Ogre-faced spiders (Deinopis) are the best known genus in this family. The name refers to the perceived physical similarity to the mythological creature of the same name. This family also includes the humped-back spiders (Menneus).

They are distributed through tropics worldwide from Australia to Africa and the Americas. In Florida, Deinopis often hangs upside down from a silk line under palmetto fronds during the day. At night, it emerges to practice its unusual prey capture method on invertebrate prey. Its eyes are able to gather available light more efficiently than the eyes of cats and owls, and are able to do this despite the lack of a reflective layer (tapetum lucidum); 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.{{cite web |url=https://australianmuseum.net.au/learn/animals/spiders/how-spiders-see-the-world/ |publisher=Australian Museum |title=How spiders see the world |date=2018-11-16 |access-date=2019-01-21}}{{Cite journal |last=Blest |first=A. D. |date=1978 |title=The rapid synthesis and destruction of photoreceptor membrane by a dinopid spider: a daily cycle |url=https://doi.org/10.1098/rspb.1978.0027 |journal=Proceedings of the Royal Society B |volume=200 |issue=1141 |pages=463–483|doi=10.1098/rspb.1978.0027 |bibcode=1978RSPSB.200..463B |s2cid=85388527 }}