Venus's flower basket

Venus's flower basket is a wonder of nature. The sponge Euplectella grow in shallow seas. Their body consist of small spicules. While growing, small fish get trapped in it. The sponge grow as a funnel and get enclosed on top. Yet they have enough spaces between their spiculous skeleton for water to pass through. The fish that get trapped in it cannot escape. If there is a couple of fish trapped in such sponges are gifted for newly married couples. The present says "Till death do us part"