Mastigias sp

Mastigias is a genus of true jellyfish in the family Mastigiidae. It contains seven described species. Members of this genus are found widely in coastal regions of the Indo-Pacific, including saline lakes of Palau (e.g., Jellyfish Lake), but there are also records from the West Atlantic at Florida and Puerto Rico. The West Atlantic records are most likely the result of accidental introductions by humans.

Mastigias sp. 1 is a rhizostome scyphozoan, with a large, conspicuous medusa and a small polyp stage. Rhizostome jellyfish of the genus Mastigias are widespread in the Indo-Pacific and they are most abundant in marine lakes on the islands. Mastigias sp. 1 was first identified from Kakaban Island, of Kalimantan, Indonesia, where the jellyfish are a tourist attraction for divers. A molecular comparison of 12 Mastigias populations found that Mastigias sp. 1 was most similar to introduced populations in Florida and Puerto Rico. Impacts have not been reported from introduced locations.