The importance of molecular characters when morphological variability hinders diagnosability: systematics of the moon jellyfish genus Aurelia (Cnidaria: Scyphozoa)

Author(s)

Lawley, Jonathan W. ^{[1, 2]} ; Gamero-Mora, Edgar ^[1] ; Maronna, Maximiliano M. ^[1] ; Chiaverano, Luciano M. ^[3] ; Stampar, Sergio N. ^[4] ; Hopcroft, Russell R. ^[5] ; Collins, Allen G. ^[6] ; Morandini, Andre C. ^{[7, 1]}

Affiliation

^[1] Univ Sao Paulo, Inst Biociencias, Dept Zool, Sao Paulo, SP - Brazil

^[2] Griffith Univ, Coastal & Marine Res Ctr, Sch Environm & Sci, Australian Rivers Inst, Gold Coast, Qld - Australia

^[3] Inst Nacl Invest & Desarrollo Pesquero, Mar Del Plata, Buenos Aires - Argentina

^[4] Univ Estadual Paulista, Fac Ciencias & Letras, Dept Ciencias Biol, Assis, SP - Brazil

^[5] Univ Alaska Fairbanks, Coll Fisheries & Ocean Sci, Fairbanks, AK - USA

^[6] NOAA, Natl Systemat Lab, Fisheries Serv, Natl Museum Nat Hist, Smithsonian Inst, Washington, DC - USA

^[7] Univ Sao Paulo, Ctr Biol Marinha, Sao Sebastiao, SP - Brazil

• Document type: Journal article
• Source: PeerJ; v. 9, SEP 9 2021.
• Web of Science Citations: 0

Abstract

Cryptic species have been detected across Metazoa, and while no apparent morphological features distinguish them, it should not impede taxonomists from formal descriptions. We accepted this challenge for the jellyfish genus Aurelia, which has a long and confusing taxonomic history. We demonstrate that morphological variability in Aurelia medusae overlaps across very distant geographic localities. Even though some morphological features seem responsible for most of the variation, regional geographic patterns of dissimilarities are lacking. This is further emphasized by morphological differences found when comparing lab-cultured Aurelia coerulea medusae with the diagnostic features in its recent redescription. Previous studies have also highlighted the difficulties in distinguishing Aurelia polyps and ephyrae, and their morphological plasticity. Therefore, mostly based on genetic data, we recognize 28 species of Aurelia, of which seven were already described, 10 are formally described herein, four are resurrected and seven remain undescribed. We present diagnostic genetic characters for all species and designate type materials for newly described and some resurrected species. Recognizing moon jellyfish diversity with formal names is vital for conservation efforts and other studies. This work clarifies the practical implications of molecular genetic data as diagnostic characters, and sheds light on the patterns and processes that generate crypsis. (AU)

• FAPESP's process: 19/03552-0 - Reproductive, behavioral and genomic patterns in Ceriantharia (Cnidaria): a step towards understanding marine evolution
• Grantee: Sérgio Nascimento Stampar
• Support type: Regular Research Grants
• FAPESP's process: 17/07317-0 - Filling the gaps in the systematics of Aurelia (Cnidaria, Scyphozoa): an integration of morphological data to known molecular species
• Grantee: Jonathan Wanderley Lawley
• Support type: Scholarships abroad - Research Internship - Master's degree
• FAPESP's process: 16/04560-9 - Patterns and processes in marine life: macroevolution in Scyphozoa (Medusozoa)
• Grantee: Maximiliano Manuel Maronna
• Support type: Scholarships in Brazil - Post-Doctorate
• FAPESP's process: 16/12163-0 - The identity of Aurelia jellyfish (Cnidaria, Scyphozoa) from the Brazilian coast and discussions on the systematics and taxonomy of the genus
• Grantee: Jonathan Wanderley Lawley
• Support type: Scholarships in Brazil - Master
• FAPESP's process: 15/21007-9 - Recognizing the diversity of jellyfishes (Medusozoa, Rhopaliophora)
• Grantee: André Carrara Morandini
• Support type: Regular Research Grants