Spiders of the World

Spider Family Key

This key lists 17 spider families along with some diagnostic features to help you identify them. Some of the features, such as the arrangements of eyes, are difficult to determine without a microscope. Therefore, we have highlighted the most useful and easy to recognize features for each family by showing them in italics. Similar information is available on Master 1.5g "Spider Family Key" in the JASON VI Curriculum. For additional information, you can also consult a field guide to spiders, such as:

Click on the name for a drawing of the spider


Trapdoor spiders (Ctenizidae) 10-33 mm (3/8-1 1/4 in) long; 6 eyes, arranged in 3 groups; jaws attached to front of head and move up and down, unlike many other spiders, in which they move x-wise. Trapdoor spiders make little silken burrows in the ground which are sealed with a hinged lid.

Spitting spiders (Scytodidae) 20 mm (3/4 in) long; 6 eyes, arranged in 3 groups; high cephalothorax; found under trash, stones or in homes. Spitting spiders squirt a sticky secretion on their prey.

Violin spider (Loxoscelidae) male: 6 mm (1/4 in) long; female: 11mm (3/8 in) long; 6 eyes, arranged in 3 pairs; normal cephalothorax; violin shaped mark on the dorsal surface of the cephalothorax. Violin spiders spin small, irregular shaped webs under bark. Poisonous to people!

Daddy-long-legs (Pholcidae)* 1-20 mm (1/16-3/4 in) long; 6 eyes arranged close together in groups of 3; two body parts; unusually thin, long legs with flexible ends. Daddy-long-legs spin irregular webs and are the most commonly found spiders in homes.

Lynx spiders (Oxyopidae) 4-16 mm (1/8-5/8 in) long; 8 eyes; 6 eyes form a hexagon with 2 smaller eyes facing forward; legs have many long, strong setae; found on tall grasses and low shrubs. Lynx spiders jump through vegetation onto their prey.

Wolf spiders (Lycosidae) 3-35 mm (1/8-1 3/8 in) long; 8 dark eyes of unequal size, arranged in 3 rows; back row of eyes are large (like car-headlights!) Wolf spiders are often found running along the ground, as well as in leaf litter, under logs, or on docks.

Nursery Web Spiders (Pisauridae) 14-16 mm (1/2-3/5 in) long; 8 eyes of equal size, in two rows; Large, similar to wolf spiders, except for the relative sizes of their eyes. Female Nursery web spiders carry their egg sacs in their jaws before placing them in leaves held together by silk. Females guard their egg sacs and young for about 1 week. Nursery web spiders can run on the surface of water.

Sac spiders (Clubionidae) 3-10 mm (1/8-3/8 in) long; 8 eyes, arranged in 2 rows; conical spinnerets; smooth, usually light brown body. Sac spiders spin saclike, resting sites.

Crab spiders (Selenopidae) 1.5-10 mm, (1/16-3/8 in) long; 8 eyes, small and well separated, arranged in 2 rows. Crab spiders hold their legs out to their sides, like crabs. They can walk fowards, backwards, or sideways. They are often found on flowers.

Jumping spiders (Salticidae) 3-15 mm (1/8-5/8 in) long; 8 eyes, 3 rows of different sizes; front central eyes are large; binocular vision; short legs; often colorful. Jumping spiders spin silken shelters under bark stones or leaves and tend to pounce on their prey.

CRIBELLATE WEB (Hackled threads)

Dictynid spiders (Dictynidae) less than 5 mm (less than 1/4 in) long;small and "dumpy"; 8 eyes, arranged in 2 rows with 6 white and 2 dark; have cribellum (plate in front of spinnerets). Dictynid spiders make small, irregular webs of hackled threads.

Uloborids (Ulobridae) 4-8 mm (1/8-1/3 in) long; 8 eyes arranged in 2 rows; have cribellum; usually "dumpy," angular, and brown. Uloborids make horizontal orb webs or triangular webs of hackled threads.


Combfooted spiders (Theridiidae) 1.4-14 mm (1/16-1/2 in) long; 6-8 eyes; usually have a globose abdomen; bristles called combs on legs, used to spin irregular webs. Combfooted spiders use their combs to fling silk strands over captive prey. Black Widow spider is shown here.

Sheet web spiders (Linyphiidae) 2-8 mm (1/16-3/8 in) long; 8 eyes, arranged in 2 parallel rows; abdomen is usually longer than wide and flat on the underside. Sheet web spiders spin flat, sheet-like or dome-shaped webs and wait behind the web until the prey gets entangled on the surface. They then pull the prey down into the web.

Funnel web weavers (Agelenidae) 1-20 mm (1/16-3/4 in) long; 8 eyes, arranged in 2 parallel rows; long spinnerets; Funnel web spiders spin extensive sheet webs leading into a funnel.

Orb weavers (Araneidae) 2-28 mm (1/16-1 1/8 in) long; 8 eyes arranged in 2 rows of 4; vary in size shape and color; abdomen is usually shaped like pancakes, but can have protuberances; Orb weavers spin spiral webs on support lines that radiate out from the center. They are often found in the center of their webs.

Long-jawed orb weaver (Tetragnathidae) 3-9 mm (1/8-3/8 in) long; 8 eyes; long legs and elongated bodies with large powerful jaws; Like Araneiae, Tetragnathidae also spin orb webs.

* Please note that the family name given here for daddy-long-legs spiders (Pholcidae) is different from the name listed in the JASON Curriculum (order Opiliones). Daddy-long-legs (order Opiliones) are commonly known as Harvestmen, and are related to spiders, but have only one body part instead of two.

Spiders of the World


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