Tarantulas comprise a group of large and often hairy spiders of the family Theraphosidae. As of December 2023, 1,100 species have been identified, with 166 genera. The term "tarantula" is usually used to describe members of the family Theraphosidae, although many other members of the same infraorder (Mygalomorphae) are commonly referred to as "tarantulas" or "false tarantulas". Some of the more common species have become popular in the exotic pet trade. Many New World species kept as pets have setae known as urticating hairs that can cause irritation to the skin, and in extreme cases, cause damage to the eyes.
Tarantula
Opening to a tarantula burrow
A Phidippus johnsoni jumping spider's fangs
A Lasiodora parahybana tarantula's fangs
Spiders are air-breathing arthropods that have eight limbs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species diversity among all orders of organisms. Spiders are found worldwide on every continent except Antarctica, and have become established in nearly every land habitat. As of November 2023, 51,673 spider species in 136 families have been recorded by taxonomists. However, there has been debate among scientists about how families should be classified, with over 20 different classifications proposed since 1900.
Spider
Palystes castaneus female, dorsal aspect pedipalp trichobothria carapace of prosoma (cephalothorax) opisthosoma (abdomen) eyes AL (anterior lateral) AM (anterior median) PL (posterior lateral) PM (posterior median) Leg segments: coxa trochanter femur patella tibia metatarsus tarsus claw chelicera
Palystes castaneus female, ventral aspect. Nos 1 to 14 as for dorsal aspect. sternum of prosoma pedicel (also called pedicle) book lung sac book lung stigma epigastric fold epigyne anterior spinneret posterior spinneret Legs are labelled I, II, III, IV from anterior to posterior.
A syrphid fly captured in the web of a spider