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Uloboridae

What do they look like?

Like all spiders, hackled orbweavers have two body-segments, a cephalothorax in front and an abdomen behind. Adults are usually 3-10 mm long. They have eight legs, all attached to the cephalothorax. On the front they have two small "mini-legs" called palps. These are used to grab prey, and in mating, and are much bigger in male spiders than in females. Females in this family are often twice as large as males.

Michigan species in this family have two rows of four eyes each, though some tropical groups only have one row.

Unlike most spiders, this family doesn't have venom glands, their bite is harmless to people.

This is one of a few spider families that make a special kind of woolly, fuzzy silk. They have special structures on their abdomen and hind legs to produce this silk and make it into webs. This is where they get their name, webs made this way are called "hackled." See the Behavior section below for more information on this special webbing.

Most Hackled Orbweavers have dull colors: cream, gray, or brown are the most common.

  • Sexual Dimorphism
  • female larger

Where do they live?

Spiders in this family are found all over the world. Most species live in warm tropical climates, but we have a few species here in Michigan.

What kind of habitat do they need?

These spiders live in places with some vegetation, so they have places to put their webs. They also prefer warm and humid habitats, but a few species live in dry or cool places too.

How do they grow?

Spiders hatch from eggs, and the hatchlings look more or less like grown-up spiders, though sometimes their colors change as they age. To grow they have to shed their exoskeleton, which they do many times during their lives.

How long do they live?

Most spiders in this family probably live only a year or two at most.

How do they behave?

These spiders often hide during the day. They don't move around too much, but stay near the spot where they build their webs. Some species are solitary, others seem to live in groups, and attach their webs together.

How do they communicate with each other?

Like most spiders, Hackled Orbweavers use web-vibrations, touching, and scents to communicate.

What do they eat?

These spiders eat small insects and other invertebrates. They spin flat webs that often look like an orb web or a piece of an orb web. Hackled orbweavers usually spin their webs horizontally, unlike the regular orbweaver family that makes their webs vertical.

The webs made by this family aren't sticky. Instead they are made with "hackled" silk, which is fuzzy and has lots of tiny fibers. These little fibers easily tangle up prey. Also, many species of hackled orbweavers stretch their webs and hold them tight. When a prey animal bumps into the web, it lets go of the web so that it collapses around the unlucky insect. Whenever they catch an animal in their web, they grab it and wrap it in more hackled silk. They don't have venom in their fangs, so they rely on their silk to hold their prey still.

  • Primary Diet
  • carnivore
    • eats non-insect arthropods

What eats them and how do they avoid being eaten?

Spiders in this family rely on their small size and camouflage colors. They often hide during the day.

How do they interact with us?

These little spiders probably help eat insect pests, but the don't have any strong impacts on humans. A few species are found around houses, and some people may consider this a nuisance.

Are they endangered?

No Hackled Orbweaver species are known to be in danger, but there are many species still unknown to science.

  • IUCN Red List [Link]
    Not Evaluated

Glossary

Australian

Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.

World Map

Ethiopian

living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.

World Map

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

Neotropical

living in the southern part of the New World. In other words, Central and South America.

World Map

Palearctic

living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.

World Map

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends.

bog

a wetland area rich in accumulated plant material and with acidic soils surrounding a body of open water. Bogs have a flora dominated by sedges, heaths, and sphagnum.

carnivore

an animal that mainly eats meat

chaparral

mid-altitude coastal areas with mild, rainy winters and long, dry summers. Dominant plant types are dense, evergreen shrubs.

crepuscular

active at dawn and dusk

ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

female parental care

parental care is carried out by females

fertilization

union of egg and spermatozoan

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

internal fertilization

fertilization takes place within the female's body

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

marsh

marshes are wetland areas often dominated by grasses and reeds.

mountains

This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

oriental

found in the oriental region of the world. In other words, India and southeast Asia.

World Map

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Climbing plants are also abundant. There is plenty of moisture and rain, but may be somewhat seasonal.

scrub forest

scrub forests develop in areas that experience dry seasons.

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

swamp

a wetland area that may be permanently or intermittently covered in water, often dominated by woody vegetation.

taiga

this biome is characterized by large expanses of coniferous forest, there is an extended cold season and heavy snowfall.

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

 
University of Michigan Museum of ZoologyNational Science Foundation

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. "Uloboridae" (On-line), Animal Diversity Web. Accessed April 17, 2014 at http://www.biokids.umich.edu/accounts/Uloboridae/

BioKIDS is sponsored in part by the Interagency Education Research Initiative. It is a partnership of the University of Michigan School of Education, University of Michigan Museum of Zoology, and the Detroit Public Schools. This material is based upon work supported by the National Science Foundation under Grant DRL-0628151.
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