Spruce-fir moss spider facts for kids
Quick facts for kids Spruce-fir moss spider |
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The spruce-fir moss spider (Microhexura montivaga) is a tiny, rare spider. It lives high up in the southern Appalachian Mountains. Scientists first found this spider in 1923. It makes its home in soft moss that grows on rocks. This moss is usually found under the thick tree branches of the forest. This spider is an endangered species, which means it is at risk of disappearing forever.
What Does It Look Like?
The spruce-fir moss spider is one of the smallest spiders in its group, called mygalomorphs. Adult spiders are only about 3 to 4 mm long. That's about the size of a pencil eraser!
Their color can be light brown, yellow-brown, or a darker reddish brown. They do not have any special marks on their bodies. The spider's mouthparts, called chelicerae, stick out in front. It also has very long spinnerets, which are used to make silk. This spider has two sets of "book lungs," which help it breathe. These look like light patches behind its belly area.
How It Lives and Eats
The spruce-fir moss spider builds small, tube-shaped webs. These webs seem to be mostly for shelter, like a tiny house. Scientists have not found any prey, or food, caught in these webs.
It probably eats tiny insects called springtails. Springtails are very common in the moss mats where the spider lives. This spider can take a long time to grow up. It might take as long as three years to become an adult. This is because the cold temperatures in its home slow down its metabolism, which is how its body uses energy.
Why Is It Endangered?
The spruce-fir moss spider was put on the endangered species list in 1995. This happened because many of the Fraser fir trees in its habitat died. These trees are very important for the spider's home.
Many Fraser fir trees died because of a tiny insect called the balsam woolly adelgid. This insect is an invasive species from Europe. When these trees die, the forest canopy becomes thinner. This means more sunlight and wind can reach the ground. As a result, the moss mats where the spiders live dry out. The spiders need a very wet and cool environment to survive. They can live in temperatures from about -17.8 °C (0 °F) to 19.8 °C (67.6 °F) in the mountains.
Where Does It Live?
The spruce-fir moss spider lives in Fraser fir and red spruce forests. These forests are found on mountain peaks in the Southern Appalachian Mountains. They are usually at heights of 1,650 m (5,410 ft) or higher. You can find them in North Carolina and Tennessee.
Some places where this spider has been found include:
- Clingmans Dome
- Mount Collins (these two have very small groups of spiders)
- Mount Le Conte
- Mount Mitchell (the spiders here are probably gone)
- Grandfather Mountain
- Roan Mountain
A group of these spiders in Sevier County, Tennessee, was once healthy. But now, they might be completely gone from that area. In two spots in North Carolina, only one spider was found recently. The only group that seems to be doing okay is along the Avery/Caldwell County line in North Carolina. This group lives on moss mats on one large rock and a few rocks nearby.
