Ground Spiders
Gnaphosidae
Classification
- Phylum: Arthropoda
- Subphylum: Chelicerata
- Class: Arachnida
- Order: Araneae
- Infraorder: Araneomorphae
- Family: Gnaphosidae
Pronunciation
How to pronounce Gnaphosidae: /ɡnəˈfɒsɪdiː/
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Summary
Gnaphosidae, or ground spiders, is a large family characterized by hunting behavior without web construction, notable for their unique spinnerets and ecological role in controlling insect populations.
Physical Characteristics
Ground spiders generally have barrel-shaped anterior spinnerets that are one spinneret diameter apart. They are identified by prominent, tube-shaped spinnerets, with an exception in the ant-mimicking genus Micaria. They also possess an indentation in the endites (mouthparts).
Identification Tips
Look for an eye arrangement that is more tightly clustered than in similar families like Clubionidae. A typical gnaphosid eye arrangement is a key identification feature.
Habitat
Ground spiders primarily hunt at night and spend the day in silken retreats, often found in leaf litter, under rocks, or in other natural debris.
Distribution
Over 2,000 described species in Gnaphosidae are distributed worldwide. 105 species are known to central Europe. Notable distribution includes the United States and Canada with varying species across states.
Diet
Ground spiders are active hunters that chase and subdue individual prey items, including insects and other spiders. They do not use webs for prey capture, instead employing thick, gluey silk to immobilize their prey.
Life Cycle
Ground spiders protect their thick-walled egg sacs until the spiderlings hatch, providing parental care during development.
Reproduction
The genitalia are diverse among ground spiders and serve as a model for studying evolution due to their peculiar copulatory mechanisms. Determined by species, mating behaviors may vary.
Ecosystem Role
Ground spiders play a crucial role as predators, controlling pest insect populations and contributing to the ecological balance.
Health Concerns
Currently, no ground spiders are known to be seriously venomous to humans.
Collecting Methods
- Active sampling by hand
- Sifting through leaf litter
- Using a sweep net in vegetation
Preservation Methods
- Dry storage in envelopes
- Alcohol preservation in jars
- Freezing for temporary storage
Evolution
Ground spiders are closely related to Clubionidae and exhibit a range of genitalia characteristics that provide insight into their evolutionary history.
Similar Taxa
Misconceptions
Ground spiders are often confused with other web-building spiders, but they do not build silk webs for trapping prey, rather they actively hunt with specialized silk techniques.
Tags
- Ground Spiders
- Gnaphosidae
- Arachnology
- Spider taxonomy
- Predatory behavior