cf. Uloborus sp. - Tecelã-Orbicular-Cribelada / Cribellate Orb Weaver / Hackled-band Orb Weaver (Latreille, 1806)
Arachnida: Araneae: Opisthothelae: Araneomorphae: Entelegynae: Uloboroidea: Uloboridae: Uloborinae
Uloborus is a spider in the order Araneae, suborder Opisthothelae, infraorder Araneomorphae, subdivision Entelegynae, superfamily Uloboroidea, family Uloboridae and subfamily Uloborinae.
Uloborus are a genus of cribellate spiders which possess eight subequal eyes of about the same length, which are arranged in two rows of four, a trait in Uloborinae shared with the subfamily Hyptiotinae within the family Uloboridae. The posterior row is strongly recurved. Anterior row is less recurved. Such traits are not equally present within the other subfamilies. The carapace is ovoid, longer than wide. The labium is semicircular in Uloborinae, a tad shorter in Miagrammopinae. The sternum is undivided. The chelicerae are robust and lack lateral condyles and venom glands, marking this family as one of the few families of spiders with the inability to inject venom in their prey. Fangs in this family are found in clusters of small teeth or fewer larger teeth. Tibiae are provided with a brush of long hairs. Uloborids possess dorsally compressed, curved metatarsus IV with an uniseriate calamistrum which is often absent in males. Uloborus' tarsus IV is longer than half the length of metatarsus IV. In some species tibia I is provided with a brush of hairs. The dorsal compression of metatarsi under calamistrum IV is indistinct in Uloborus. Epigyne with paired projections in Uloborus. Sometimes, males possess palps relatively large compared to their size. The female palp has dentate claws and the palpal femur has a small tubercle in many species.
The genus Uloborus often reinforce their webs with stabilimenta. Their silk is unequal with most other spiders': the Uloborus spin their webs differently; the webs are fluffy and made of nanoscale filaments. There is a theory which suggests that the reason to this is for the capture of prey through electrostatic charge. This theory says the silk seems to emerge as liquid from the silk glands and is pulled over a comblike plate on the hind legs which also gives it the appearance of wool. This technique gives them a charge and the "electrostatic fibers are thought to attract prey to the web in the same way a towel pulled from the dryer is able to attract stray socks." - This theory requires scientific confirmation and I know no scientific embasement for it on Uloborus, so providing me with a background confirming this will allow me to post this as a fact instead of a theory.
A little trivia: In the Pokémon franchise, Galvantula is an Electric-Type / Bug-Type spider which can learn the move "Electroweb".
The genus has around 72 described species that mostly occur in the tropics and subtropics with modest representation in temperate areas. Only a few species can be found in North America and Europe. Apparently, a few species from this genus were moved to Philoponella, a genus in which some species construct communal webs, Astavakra, Octonoba, Zosis, Tangaroa, Daramulunia, Purumitra, Psechrus, Sybota and Waitkera; hence the doubt on the genus ID. (https://wsc.nmbe.ch/genus/3810/Uloborus)
The genus name comes from the Greek "ouloboros" which translates to "with deadly bite", even though the whole family Uloboridae lacks venom glands.
Members of the family Uloboridae are the only cribellate spiders that spin capturing webs in the form of orbs or portions of orbs. A few species of Uloborus weave their webs in a horizontal position. "The common name of hackled-band orb weavers comes from the fact that the spiral portion of the web is constructed of an unusual type of silk thread known as hackled band." ... "Respiratory system consisting of a pair of book lungs at base of abdomen and single, median, tracheal spiracle near cribellum. Spinnerets of average size, set close together, six in number; front and hind pairs two-segmented, but apical segments small." - (http://digitallibrary.amnh.org/bitstream/handle/2246/3363/N2196.pdf) - more information can be found here
Data: 9th of September, 2018 at 07:57:05am
Local: Brazil, Ceará, Fortaleza (Lat: -3.7514670919346025, Long: -38.48386227923129, Accuracy in meters: 38.39012013818538)
No species identified
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