Spider
Videos
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.
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
Spinneret
Videos
A spinneret is a silk-spinning organ of a spider or the larva of an insect. Some adult insects also have spinnerets, such as those borne on the forelegs of Embioptera. Spinnerets are usually on the underside of a spider's opisthosoma, and are typically segmented. While most spiders have six spinnerets, some have two, four, or eight. They can move both independently and in concert.
The spinnerets of an Australian garden orb weaver spider.
Black spinneret of Phidippus adumbratus visible below red abdomen
The compact spinnerets of Argiope bruennichi; placed ventrally below the posterior.
A barn spider encases her prey in silk emanating from her spinneret seen in the foreground.