Friday, February 18, 2022

[Cnidaria • 2022] Cassiopea mayeri • Revealing Hidden Diversity among Upside-down Jellyfishes (Scyphozoa: Rhizostomeae: Cassiopea): Distinct Evidence allows the Change of Status of A Neglected Variety and the Description of A New Species


Cassiopea mayeri
Gamero-Mora, Collins, Boco, Geson & Morandini, 2022


Abstract
Morphological variability within Cassiopea is well documented and has led to inaccuracies in the establishment of species boundaries in this taxon. Cassiopea medusae specimens from the Western Pacific (Japan and the Philippines) were analysed using multiple lines of complementary evidence, including types of cnidae, macro-morphology and molecular data. These observations lead to the recognition of two distinct species: Cassiopea mayeri, sp. nov. and a previously synonymised variety now raised to species level (Cassiopea culionensis, stat. nov.). These species can be distinguished from each other using morphological features. Herein, sexually dimorphic traits are included for the first time in the descriptions of Cassiopea species. Nematocyst types not previously observed in the genus are also reported. Molecular analyses, based on individual and combined markers (16S + cytochrome c oxidase I, COI), also support two distinct species; they are not sister taxa, and both are nested together within a clade of other Cassiopea members from the Australian and Indo-Pacific regions. Species richness is underestimated in the Western Pacific region, and integrative approaches are helpful to reveal and describe species. The systematics of Cassiopea is far from completely understood, but the present study represents an important further step.
 
Keywords: Cassiopea, DNA barcoding, jellyfish, morphology, Pacific Ocean, phylogeny, species delimitation, taxonomy.




Cassiopea mayeri


Edgar Gamero-Mora, Allen G. Collins, Sheldon Rey Boco, Serafin Mendez Geson III and André C. Morandini. 2022. Revealing Hidden Diversity among Upside-down Jellyfishes (Cnidaria: Scyphozoa: Rhizostomeae: Cassiopea): Distinct Evidence allows the Change of Status of A Neglected Variety and the Description of A New Species. Invertebrate Systematics. 36(1); 63-89. DOI:  10.1071/IS21002

International team of scientists discover new jellyfish species in PH