Integrating molecular and morphological evidence revives the blubber jellyfish, Catostylus purpurus (Scyphozoa: Rhizostomeae; Catostylidae) of the Indo-Pacific (Philippines)

Jellyfishes have ecological and societal value, but our understanding of taxonomic identity of
\nmany jellyfish species remains limited. Here, an approach integrating morphological and
\nmolecular (16S ribosomal RNA and cytochrome oxidase I) data enables taxonomic assessment
\nof the blubber jellyfish found in the Philippines. In this study, we aimed to resolve
\ndoubt on the taxonomy of Acromitoides purpurus, a valid binomen at the time of our research.
\nOur morphological findings confirm that this jellyfish belongs to the genus Catostylus, and is
\ndistinct from known species of the genus inhabiting the Western Pacific, such as Catostylus
\nouwensi, Catostylus townsendi, and Catostylus mosaicus. Detailed morphological and molecular
\nanalyses of the type specimens from the Philippines with the other Catostylus species revive
\nthe binomen Catostylus purpurus and invalidate A. purpurus. Genetic analysis also distinguishes
\nthis Philippine jellyfish from C. townsendi and C. mosaicus. Through this study, we
\narranged several Catostylidae taxa into species inquirendae (Catostylus tripterus, Catostylus
\nturgescens, and Acromitoides stiphropterus) and one genus inquirenda (Acromitoides) and
\nprovided an identification key for species of Catostylus. This comprehensive study confirms
\nthe blubber jellyfish as C. purpurus, enriching our understanding of jellyfish biodiversity.
\nThe integration of morphological and genetic analyses proves vital in resolving taxonomic
\nambiguities within the Catostylidae family and in the accurate identification of scyphozoan
\njellyfishes.