Uloboridae is a family of non-venomous , known as cribellate orb weavers or hackled orb weavers. Their lack of venom glands is a secondarily evolved trait. Instead, they wrap their prey thoroughly in silk, cover it in regurgitated digestive enzymes, and then ingest the liquified body.
Description
They are medium to large spiders, with three claws, which lack venomous glands. They build a spiral web using
cribellate silk, which is quite fuzzy. They are usually dull in color and are able to camouflage well into their surroundings. They typically have a humped
opisthosoma, which is notoriously more humped than the
carapace. Their rear
Spider vision tend to curve, more so in some species than others.
Most uloborid spiders have eight eyes, but the genus
Miagrammopes has only four.
Hunting
The hunting method of these
Spider is quite unique among all
Animal in the kingdom. These spiders do not use an adhesive on their orb
spider web, but rather the very fine
cribellate fibers on each strand of
Spider silk tend to ensnare prey.
Since newly hatched uloborids lack the cribellum needed to produce cribellate sticky silk, their webs have a fundamentally different structure with a large number of fine radii, but no sticky spiral.
Some spiders only build a single line web, while others make more complex webs. They lack
venom glands, which is very rare among spiders. They first catch their prey, using their silk. They wrap their prey, and severely compress it, then they cover the prey with
digestive fluid. Oddly enough, their mouthparts never touch the prey. The spider starts ingesting as soon as the prey has been covered. It is thought that robust hairs protect the spider from the digestive fluids.
It is unknown how this behavior first evolved.
Social behavior
Some species are able to form colonies
like
Philoponella congregabilis, which make large, messy, communal webs. Colonies may range from a couple of individuals to a couple hundred. These colonies may be nymph dominated or adult dominated, though a small colony dominated by adults could be a sign of the colony's slow death. These colonies show signs of being female dominated, as one would expect, with males only being found in larger colonies. This could mean males search for larger colonies, or had died out in the smaller colonies.
Distribution
This family has an almost worldwide distribution. Only two species are known from Northern Europe:
Uloborus walckenaerius and
Hyptiotes paradoxus. The oldest known fossil species is
Talbragaraneus from the
Late Jurassic (
Tithonian) Talbragar Fossil Bed of Australia.
Genera
Hyptiotes cavatus 439416895.jpg| Hyptiotes cavatus
Miagrammopes_brevicaudus_300127026_540742501.jpg| Miagrammopes brevicaudus
Octonoba.grandiprojecta.male.-.takinawa.jpg| Octonoba
Philoponella_congregabilis_8720345.jpg| Philoponella congregabilis
, this family includes twenty genera:
-
Anatoborus Milledge, 2025 – Australia
-
Ariston O. Pickard-Cambridge, 1896 – Panama, Mexico, Brazil, Colombia
-
Astavakra Lehtinen, 1967 – Philippines
-
Conifaber Opell, 1982 – South America
-
Daramulunia Lehtinen, 1967 – Fiji, Vanuatu, Samoa
-
Hyptiotes Walckenaer, 1837 – Algeria, Tunisia, South Africa, Asia, Madeira, Russia, Greece, France, North America
-
Lehtineniana Sherwood, 2022 – New Caledonia, Vanuatu, Cook Islands, French Polynesia, Caroline Islands
-
Lubinella Opell, 1984 – New Guinea
-
Miagrammopes O. Pickard-Cambridge, 1870 – Mauritius, Tanzania, Eswatini, South Africa, Asia, North America, Australia, Papua New Guinea, South America
-
Octonoba Opell, 1979 – Eastern Asia, Caucasus, Russia. Introduced to United States
-
Orinomana Embrik Strand, 1934 – South America
-
Philoponella Mello-Leitão, 1917 – Angola, South Africa, Ivory Coast, Asia, Mexico, Costa Rica, United States, South America, Australia. Introduced to New Zealand
-
Polenecia Lehtinen, 1967 – Mediterranean to Azerbaijan
-
Purumitra Lehtinen, 1967 – Philippines, Australia, Caroline Islands
-
Siratoba Opell, 1979 – Mexico, United States
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Sybota Simon, 1892 – Argentina, Chile
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Uaitemuri Santos & Gonzaga, 2017 – Brazil
-
Uloborus Latreille, 1806 – Worldwide
-
Waitkera Opell, 1979 – New Zealand
-
Zosis Walckenaer, 1841 – Brazil, Galapagos, Guyana, Timor. Introduced worldwide
See also
-
List of Uloboridae species
External links
