Biologist Sarah McAnulty tweeted about this unusual symbiosis between a species of Euplectella glass sponge known as the "Venus flower basket" and a species of crustacean that live entrapped inside it all their lives:
The most famous glass sponge is a species of Euplectella, known as the “Venus flower basket,” which builds its skeleton in a way that entraps a certain species of crustacean inside for life. This sponge often houses two small, shrimp-like Stenopodidea, a male and a female, who live out their lives inside the sponge. The crustaceans breed, and when their offspring are tiny, they escape to find a new Venus flower basket of their own. The pair inside the basket clean it and, in return, the basket provides food for the crustaceans through its waste. The animals eventually grow too large to escape the sponge, so they are forced to "stay put" for the rest of their lives.
The "till death do us part" eternal-love nature of the trapped crustaceans make it the perfect symbolic gift for a marriage in Japanese culture!
YO! There’s a “glass” sponge that has a little shrimp living in it, and the sponge grows around the little shrimp then the shrimp is trapped in there for LIFE.
— Sarah McAnulty (@SarahMackAttack) June 27, 2019
The Japanese used to give them as wedding presents bc the sponge and shrimp are “til death do us part” #AOtrips pic.twitter.com/f9q01ArJmM
(Top image: NOAA Office of Ocean Exploration and Research/NOAA Photo Library/wikimedia)