Opisthothelae

Opisthothelae

A mouse spider, a member of the Opisthothelae.

Opisthothelae is a suborder of spiders that includes the majority of spider species. This suborder is divided into two infraorders: Mygalomorphae and Araneomorphae. Opisthothelae is characterized by the presence of a single pair of book lungs and the absence of a cribellum, a silk-spinning organ found in some other spiders.

Classification

The suborder Opisthothelae is divided into two main infraorders:

• Mygalomorphae: This infraorder includes spiders such as tarantulas and trapdoor spiders. Mygalomorphs are generally characterized by their large size, robust bodies, and downward-facing fangs.

• Araneomorphae: This is the largest infraorder of spiders, containing the majority of spider species. Araneomorphs are distinguished by their more advanced web-spinning abilities and a wide variety of hunting strategies.

Characteristics

Opisthothelae spiders are known for their unique respiratory system, which includes a single pair of book lungs. This adaptation allows for efficient gas exchange and is a key feature distinguishing them from other spider groups. Additionally, the absence of a cribellum in Opisthothelae spiders differentiates them from the Mesothelae, another suborder of spiders.

Habitat and Distribution

Opisthothelae spiders are found worldwide, inhabiting a diverse range of environments from tropical rainforests to arid deserts. Their adaptability to different habitats is a testament to their evolutionary success.

Behavior

The behavior of Opisthothelae spiders varies widely between species. Some, like the orb-weaver spiders, are known for their intricate web designs, while others, such as the wolf spiders, are active hunters that do not rely on webs to capture prey.

Importance to Ecosystems

Opisthothelae spiders play a crucial role in ecosystems as both predators and prey. They help control insect populations and serve as a food source for various animals, including birds and small mammals.

Related Pages

• Spider anatomy
• Spider silk
• Spider behavior
• Arachnology