Treasures of Mt. Takao

Mt. Takao has abundant nature with warm-temperature forests and temperate forests. There are a lot more species could be called as "treasure" inhabits other than explained in animals, insects and birds section. Spiders is one of them because they are beneficial insects and its prey is destructive insects. Over 300 species including rare ones inhabits and Mt. Takao is the mountain with the largest number of species of spiders and widely known as a paradise for spiders.

Geothelphusa dehaani (Japanese Freshwater Crab)
Geothelphusa dehaani (Japanese Freshwater Crab) Potamidae
Main Region: Honshu, Shikoku, Kyushu, Sado Island, Oki Island, Tanega Island and Yaku Island. Found in valleys, mountain streams, swamps with many rocks and fallen leaves from low elevations to mountains. Is freshwater crabs prefer clear water from upstream to midstream and stay mostly under grabbles and fallen trees in water. Body color varies to three types, purple-black, red-brown and gray-blue varies by region. The found in Mt. Takao is brown shell with dark-yellow cheliped. Is mostly active at night but sometimes seen on mountain trails during daytime on rainy or cloudy days. Is an omnivore and feed on small insects, snails, earthworms and plants or fallen leaves on waterside. Female lays 50 eggs and hold them on abdomen to protect until they hatch. When it becomes closer to winter, hide under rocks in water and spend winter.

●Length  about 20 to 30 mm (Width of shell)
●Adults Flight Season  March to about November
※Quotation from Mount Takao formula application
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