Obelia is a female name of Greek origin, meaning "Needle." The name is associated with a genus of hydrozoans, aquatic organisms with both polyp and medusa stages in their life cycle. Obelia species are mainly found in marine and some freshwater environments, with a worldwide distribution, except in the high-Arctic and Antarctic seas. The life cycle of Obelia involves asexual reproduction through polyp colonies, followed by the release of free-swimming male and female medusae for sexual reproduction. These organisms have a simple structure with two true tissue layers and a nerve net, and they feed on crustaceans, ciliates, and microplankton. Phylogenetic studies have revealed distinct haplotypes and evidence of glacial refugia, indicating their evolutionary history and distribution. The name Obelia reflects the unique characteristics and life cycle of the hydrozoan genus, making it a distinctive and meaningful choice for a female name of Greek origin.