Osmunda japonica

No.03 Japanese Royal Fern

Osmunda japonica is a species of fern known in Japan as “Zenmai.” Zenmai produces both fertile and non fertile fronds, which can grow up to 50 cm and one meter tall, respectively. Like others in the Osmunda genus, the fertile fronds of the Japanese Royal Fern contain spores that darken and give the appearance of “flowering.” The fern is native to Japan, China, Korea, Taiwan, and eastern Russia. The immature fronds of the fern sprout in a tall spiral and can be collected and eaten as a vegetable.

Branchiostoma japonicum

No.05 Japanese lancelet

Branchiostoma japonicum is a species of lancelet (or “amphioxus”) that belongs to a subphylum of Chordata called Cephalochordata. Members of this subphylum are translucent, resemble fish, and retain their notochord into adulthood, but have no true vertebrae or skeleton. Because of their morphology and their phylogenetic closeness to chordates, lancelets are important in studies of vertebrate evolution. Japanese lancelets grow up to 5 cm long and live in subtidal zones where they anchor themselves in sand and filter-feed using their cilia. This lancelet is primarily found in Japanese waters but has also been found in waters near Xiamen, China.

Dugesia japonica

No.29 Type of Planarian

Dugesia japonica is a notable non-parasitic flatworm found across East Asia. Growing between 10-35 mm long and 1.5-7 mm wide, it has an elongated brown body, a triangular head, and two eyes. It is the most common freshwater planarian found in Japan, and resides in both running and standing water. Like others in its genus, Dugesia japonica is famous for being able to completely regenerate itself from a small, amputated part of its body. It also has a well-organized brain with decision-making capabilities. Because of this, Dugesia japonica is used as a model organism within neurobiology and regenerative medicine.

Mauremys japonica

No.06 Japanese Pond Turtle

Mauremys japonica is a species of freshwater turtle native to Japan. Females of this species can grow shells up to 21 cm long, while males grow smaller shells up to 14 cm long. Found across Japan except for the northern island of Hokkaido, Japanese pond turtles live in rivers, marshes, ponds, and irrigated rice fields. Its diet can include small amphibians, insects, algae, and earthworms. Although not currently considered threatened, habitat destruction via land development, exploitation from the pet trade, and the introduction of invasive turtle species have caused concern for native populations of Mauremys japonica.