Invertebrates

Tarantulas are seen in the park during the day from time to time. Females can live for more than 20 years.

NPS Photo

Hundreds of species of insects, arachnids and other invertebrates find a home in the unique ecosystems of Montezuma Castle National Monument. These include harmless tarantulas as well as venomous black widow spiders and Arizona bark scorpions. However, these often misunderstoood desert inhabitants pose little threat to humans. The invertebrates found at Montezuma Castle and Montezuma Well reveal extraordinary evolutionary adaptations for survival in an arid desert environment.

Crustaceans

Crayfish, also known as crawdads and crawfish, live in freshwater habitats such as streams, rivers, swamps, and ponds. There are over 500 species worldwide and about 150 species in North America. Crayfish are not native to Arizona. Originally released into reservoirs and large bodies of water as a food source for sport fish by people unaware of the devastating consequences, crayfish have invaded previously pristine waters negatively impacting native fish and aquatic ecosystems. This primarily nocturnal, armor-covered crustacean has few natural predators, is omnivorous, and competes for resources with fish, frogs, insects, and turtles. The crayfish propels itself backward through the water by using its tail composed of a central section called a telson and uropods on each side. It is able to walk on land and in the water by using its 4 pairs of walking legs. Each leg has an attached gill that occupies the bronchial chamber. The crayfish senses its world with its eyes, two pairs of antennae, and pincers called chelipeds. Crayfish have the ability to regenerate lost limbs. They molt as they grow, and often eat the old shell.