As jellyfish are not vertebrates, let alone true fish, the word jellyfish is considered by some to be a misnomer. Public aquariums may use the terms jellies or sea jellies instead. Indeed, it may be said that the term “jellies” has become more popular than “jellyfish”. In scientific literature, “jelly” and “jellyfish” are often used interchangeably. Some sources may use the term “jelly” to refer to organisms in this taxon, as “jellyfish” may be considered inappropriate.