Pelagiidae

Pelagiidae is a family of pelagic jellyfish in the class Scyphozoa. The family includes several genera, with the genus Pelagia being the most prominent and Pelagiidae’s type genus being Pelagia. Members are true jellyfish characterized by free-swimming medusae with a bell-shaped body and marginal, often lengthy tentacles.

Morphology and life cycle: Medusae in this family are typically umbrella-shaped and translucent, frequently displaying pink or purple hues. The tentacles and, in many species, oral arms surround the margin of the bell. Like other scyphozoans, Pelagiidae species have a life cycle that includes a sessile polyp stage, which reproduces asexually, and a free-swimming medusa stage that is sexual.

Distribution and habitat: Pelagiidae jellyfish are cosmopolitan, inhabiting temperate and tropical oceans. They are common in open waters as well as coastal zones. Pelagia noctiluca, commonly called the mauve stinger, is a well-known member with a wide distribution in the Mediterranean, Atlantic, and parts of the Indian Ocean.

Ecology and human interactions: Pelagiidae medusae feed primarily on small zooplankton. Their nematocysts can deliver stings to humans, which are typically painful but not usually life-threatening, depending on species and individual sensitivity. Blooms can occur in nutrient-rich waters and are more common in warm seasons.

Taxonomy and notes: The family belongs to Scyphozoa and is defined by morphological features of the medusa forms. Besides Pelagia, the family includes additional genera, all sharing pelagic, free-swimming medusae adapted to open-ocean life.