Spider Families

Spiders are often easiest to approach first by family rather than by species. Family-level identification uses broad field-visible traits such as body shape, eye arrangement, leg posture, web type, hunting behavior, habitat, and overall appearance.

This index collects family-level field notes for spiders and related arachnid observations. These pages are intended for photographic reference and field study, especially when a spider cannot be confidently identified to genus or species.

How to Use These Family Pages

Start with the most visible traits in the photo or observation:

Web type: orb web, sheet web, funnel web, cobweb, retreat, burrow, or no web visible
Body shape: round, flattened, long-bodied, compact, robust, slender, crab-like, or long-legged
Leg posture: forward-facing, sideways, spread, curled, jumping stance, or held in pairs
Eye arrangement: when close views are available
Habitat: flowers, shrubs, grasses, bark, leaf litter, water margins, buildings, gardens, or woodland edges
Behavior: ambush hunting, jumping, active ground hunting, web tending, retreat building, egg sac guarding, or fishing behavior

Family identification is often possible from good photographs, but genus or species identification may require additional views, mature individuals, or close inspection of reproductive structures.

Family-Level Identification Characters

Useful field characters may include:

Body shape and size: overall proportions, flattened or rounded form, abdomen shape
Cephalothorax shape and markings: color, stripes, central bands, lateral markings
Abdomen shape and pattern: spots, chevrons, leaf-like markings, humps, bands, or mottling
Eye arrangement: size and placement of front, side, and rear eyes
Leg length, banding, spines, or posture: especially useful in crab spiders, jumping spiders, orb-weavers, and wolf spiders
Pedipalps or epigyne, when visible: useful for mature individuals
Spinnerets or posterior features: especially helpful in some ground spiders and funnel weavers
Color pattern: dorsal and lateral markings, contrast, camouflage, or warning-like colors
Hair, setae, spines, or surface texture: smooth, hairy, bristly, spiny, or flattened
Web type, retreat, burrow, or hunting style: often one of the strongest family clues
Behavior or habitat association: flowers, bark, leaf litter, grass, water, buildings, or garden vegetation

Representative Spider Families

These are common or photographically useful families that may be included in this section of the field notes.

Orb-Weavers

Araneidae – Typical orb-weavers. Often build circular orb webs; many have rounded abdomens, strong markings, and conspicuous garden or woodland webs.
Tetragnathidae – Long-jawed orb-weavers. Often slender-bodied with long legs; many rest stretched along stems, grasses, or vegetation near water.

Ambush and Flower Spiders

Thomisidae – Crab spiders. Usually flattened or crab-like, with the front legs held outward or sideways; many are ambush hunters on flowers, leaves, bark, or low vegetation.

Jumping and Active Hunters

Salticidae – Jumping spiders. Compact-bodied spiders with large forward-facing eyes, alert behavior, and active visual hunting.
Lycosidae – Wolf spiders. Active ground hunters, often robust and well camouflaged; females may carry egg sacs or spiderlings.
Gnaphosidae – Ground spiders. Usually fast-moving hunters found under debris, leaf litter, stones, bark, or on open ground.

Web Builders and Retreat Spiders

Agelenidae – Funnel weavers and grass spiders. Often build sheet-like webs with a funnel retreat; many have long spinnerets.
Theridiidae – Cobweb spiders. Often build irregular three-dimensional cobwebs; body shape varies from rounded to small and delicate.
Linyphiidae – Sheetweb and dwarf spiders. Often small, delicate spiders associated with sheet webs in grasses, shrubs, leaf litter, and low vegetation.
Dictynidae – Meshweb spiders. Small spiders often associated with irregular mesh-like webs on vegetation, walls, bark, or structures.

Nursery Web, Fishing, and Long-Legged Spiders

Pisauridae – Nursery web and fishing spiders. Often long-legged hunters; some occur near water, and females may carry egg sacs or guard nursery webs.
Pholcidae – Cellar spiders. Long-legged, delicate spiders often found in buildings, basements, caves, and sheltered corners.

Sac and Foliage Spiders

Clubionidae – Sac spiders. Often found in folded leaves, retreats, bark crevices, or sheltered vegetation.
Anyphaenidae – Ghost spiders. Active hunters often found on foliage, shrubs, trees, and human-made structures.

Similar Families and Distinguishing Features

Many spider families overlap in size, color, and general appearance. The following comparisons are often useful in field photographs.

Araneidae vs. Tetragnathidae: both may build orb webs, but tetragnathids are often more elongated and long-legged, while many araneids are more rounded or robust.
Thomisidae vs. Salticidae: crab spiders often hold the front legs sideways and rely on ambush, while jumping spiders usually have large forward-facing eyes and active visual behavior.
Lycosidae vs. Agelenidae: wolf spiders are active ground hunters and usually not found sitting in funnel webs; grass spiders often remain on or near funnel-shaped sheet webs.
Theridiidae vs. Linyphiidae: both may be small web builders, but theridiid webs are often irregular cobwebs, while linyphiid webs are commonly sheet-like.
Pisauridae vs. Lycosidae: both can be large active hunters, but pisaurids are often longer-legged and may be associated with water, vegetation, or nursery webs.

Life Cycle and Ecology

Spiders are important predators in gardens, woodlands, wetlands, grasslands, and human-made habitats. Family-level behavior often gives strong clues about ecology.

Common ecological notes to record include:

egg sacs and whether the female carries or guards them
juvenile development and seasonal appearance
adult activity period
prey capture strategy
web placement, retreat structure, burrow use, or hunting behavior
association with flowers, bark, grass, leaf litter, water, buildings, or garden plants
overwintering stage when known
predator/prey interactions
local habitat preferences

Photographing Spiders for Identification

For better family, genus, or species identification, try to photograph:

dorsal view of the whole spider
side view showing body height and leg posture
front view showing eyes and face
close view of abdomen markings
leg banding, spines, and relative leg length
web, retreat, burrow, egg sac, or surrounding habitat
behavior, such as hunting, carrying young, guarding eggs, or tending a web

Use the Spider Photographic Checklist to record useful identification views and field notes.

Family overview intended for field study and photographic reference. Some identifications may require close inspection, multiple views, mature specimens, microscopic characters, or specialist references.