Cnidome and Morphological Features of Pelagia noctiluca (Cnidaria: Scyphozoa) Throughout the Different Life Cycle Stages

Pelagia noctiluca is considered the most important jellyfish in Mediterranean Sea, due to its abundance and severity of stings. Despite importance marine ecosystems health problems caused by massive arrival coastal areas, little known about early life stages cnidome has never been described. This study morphological anatomical features throughout cycle identifies four stages: two ephyra metaephyra stages. Ephyra stage 1, newly developed from a planula, no velar canals, gastric filaments or nematocyst batteries. 2, cruciform-shaped manubrium filaments. Metaephyra 3 eight tentacle buds clusters for first time. Lastly, 4, primary tentacles grow nearly simultaneously, with secondary tentacles. Complete battery patterns gradually develop later Four types are identified: a-isorhiza, A-isorhiza, O-isorhiza eurytele. Of these, a-isorhiza eurytele entire cycle, while A-isorhiza have more role advanced All nematocysts show positive correlation between increasing capsule volumes body diameter ephyrae, metaephyrae, young medusae adult medusae. In stages, euryteles larger than those exumbrella, indicating that volume critical absence marginal tentacles, specialized feeding. provides updated information, extensive description date, including high-resolution photographs schematic drawings all developmental P. noctiluca. Additionally, characterization provided each facilitate accurate identification this species when collected water column, raise awareness potential human envenomation.