Caulerpa is a genus of seaweeds in the family Caulerpaceae (among the green algae). They are unusual because they consist of only one cell with many nuclei, making them among the biggest single cells in the world. A species in the Mediterranean can have a stolon more than 3 metres (9.8 ft) long, with up to 200 fronds. This species can be invasive from time to time.

Some species of Caulerpa are edible. The two most commonly eaten are Caulerpalentillifera and Caulerparacemosa, both called “sea grapes” in English. Both are traditionally harvested in the wild and sold in local markets in Southeast Asia, Oceania, and East Asia. They are eaten raw in salads and have a characteristic “sea” flavor and a crunchy texture.

Only C. lentillifera is cultivated in aquaculture. Its cultivation began in the 1950s in Cebu, Philippines, after accidental introduction of C. lentillifera to fish ponds.[7] This was followed by Japan in 1986, where it was cultivated in tanks in the tropical waters of Okinawa.[8] Commercial cultivation has since spread to other countries, including Vietnam, Taiwan, and China (in Fujian and Hainan). Most are for domestic consumption, but they are also exported to Japan.