14.1. Bothriocyrtum californicum: Trapdoor Spider http://www.ck12.org
14.1 Bothriocyrtum californicum: Trapdoor Spi-
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Common Name
- California Trapdoor Spider
Description
The trapdoor spider was once very common in Southern California but became less common due to loss of habitat.
It can measure from 0.79 in. to 1.26 in. long and is black, brown, and yellow in color. They resemble tarantulas but
with smaller, shinier bodies.
- Kingdom: Animalia
- Phylum: Arthropoda
- Class: Arachnida
- Order: Araneae
- Family: Ctenizidae
- Genus:Bothriocyrtum
- Species:B. californicum
Habitat
The trapdoor spider lives in grassy areas, hillsides, and dirt embankments. They’re range is the southern half of the
U.S. from Virginia, south to Florida, and then west to California. The spider builds it’s burrow underground. The
length of a trapdoor spider’s burrow can range from 2.5 cm. to 5 cm. Larger burrows have multiple entrances, and
the spider will cover each entrance with a door that opens and closes on a hinge of silk. The burrow usually faces
directly into sunlight and is near vegetation.
Cell Biology
Trapdoor spiders have eukaryotic cells. Eukaryotic cells contain a nucleus and many other organelles. An organelle
is a special subunit within a cell that has its own function. Cells in a species can divide through two ways: mitosis
and meiosis. Mitosis is the entire process of cell division including the nucleus and the cytoplasm. Meiosis is the
process of cell division in a sexually reproducing way that reduces the number of chromosomes in reproductive cells.
Through the process of meiosis, the trapdoor spider makes sperm and eggs that have half the chromosomes of the
original cell. Chromosomes are made of DNA, which has genes with codes for the spider’s traits.