Itsukushima Shrine: Venus’ Flower Basket
One of the most remarkable items in the Itsukushima Shrine collection of treasures is this deep-sea sponge––a tubular, basket-like organism native to the western Pacific Ocean. Inside it lie two small, shrimp-like creatures that are closely related to lobsters and crabs. These two Spongicolidae, a male and a female, live their entire lives inside the sponge. They clean it and, in return, benefit from nutrients that the sponge traps in its tissues and then releases into the basket. The sponge and the shrimp couple that it hosts exist in symbiosis, and when one party dies, so does the other.
This relationship, in which the two shrimp live out their lives together and are “buried” side by side within the Venus’ flower basket, was traditionally thought to symbolize a happy marriage. Sponges with shrimp inside were therefore considered auspicious items and were dried and given as wedding gifts. The Venus’ flower basket is commonly found at depths of 350 to 1,000 meters, and this deep-sea habitat made these sponges a coveted rarity in traditional Japan. The specimen seen here comes from Suruga Bay in present-day Shizuoka Prefecture.