7 species, see text Mastigias is a genus of true jellyfish in the family Mastigiidae.

[3] Mastigias organisms also are able to produce swimming frustules, a hard and porous cell wall covering diatoms.

[4] The genus Mastigias is native to the western and central Indo-Pacific, from Australia to Japan, and Micronesia to the Indian Ocean.

[9] Mastigias jellyfish have a symbiotic relationship with zooxanthellae[10] living in host gastrodermal cells where they exhibit phased division.

[11] The Mastigias genus of jellyfish symbiotically produce ephyrae only in the presence of Symbiodinium, in a process called strobilation.