Cannonball jellyfish Cannonball jellyfish The cannonball jellyfish ("Stomolophus meleagris"), also known as the cabbagehead jellyfish, is a species of jellyfish in the family Stomolophidae. Its common name derives from its similarity to a cannonball in shape and size. Its dome-shaped bell can reach in diameter and the rim is sometimes colored with brown pigment. Underneath the body is a cluster of oral arms that extend out around the mouth. These arms function in propulsion and as an aid in catching prey. Cannonballs are prominent from North America's eastern seaboard all the way to Brazil, but are also found in parts of the
Jellyfish authorities state that neither of these are jellyfish, which they consider should be limited to certain groups within the medusozoa. The non-medusozoan clades called jellyfish by some but not all authorities (both agreeing and disagreeing citations are given in each case) are indicated with "???" on the following cladogram of the animal kingdom: Jellyfish are not a clade, as they include most of the Medusozoa, barring some of the Hydrozoa. The medusozoan groups included by authorities are indicated on the following phylogenetic tree by the presence of citations. Names of included jellyfish, in English where possible, are shown in boldface;