Pentaplacodinium lapazense sp. nov. from Central and Southern Gulf of California, a new non-toxic gonyaulacalean resembling Protoceratium reticulatum

• Published in: Marine micropaleontology 2023-01, Vol.178, p.102187, Article 102187
• Main Authors: Mertens, Kenneth Neil, Morquecho, Lourdes, Carbonell-Moore, Consuelo, Meyvisch, Pjotr, Gu, Haifeng, Bilien, Gwenael, Duval, Audrey, Derrien, Amélie, Pospelova, Vera, Śliwińska, Kasia K., Gárate-Lizárraga, Ismael, Pérez-Cruz, Beatriz
• Format: Article
• Language: English
• Subjects: Bahía Concepción; Bahía de La Paz; Life Sciences; micro-FTIR spectroscopy; Operculodinium; Yessotoxins
• ISSN: 0377-8398; 1872-6186
• DOI: 10.1016/j.marmicro.2022.102187

A new Pentaplacodinium species with six precingular plates is described from Bahía Concepción and Bahía de la Paz, Gulf of California. The non-fossil motile stage is described as Pentaplacodinium lapazense, whilst the fossil stage is described as Operculodinium lapazense. The cyst morphology is compared to topotype material of Operculodinium israelianum, which is larger, has longer processes and has a different wall structure. The motile cells display a plate formula of Po, Pt, X, 2′+*2′, 6′′, 6c, 7s, 5′′′, 1p, 1′′′′. A typical gonyaulacalean fission line and plate overlap are observed. SSU-ITS-LSU ribosomal DNA sequences demonstrate that Pentaplacodinium saltonense is its closest relative. The species is homothallic. This species occurs in relatively shallow and restricted coastal areas, and has a preference for higher sea-surface temperatures and salinities. Micro-FTIR spectra of the cysts are compared to spectra of cysts of other gonyaulacaleans and suggest very similar compositions. No yessotoxins were detected in any of the analyzed strains, hence, this species is unlikely to be responsible for the elevated yessotoxin concentration observed in shellfish on the southern and central coastal region of the Gulf of California. •A new species Pentaplacodinium lapazense is described from the southwestern coastal region of the Gulf of California, Mexico.•The plate formula is: Po, Pt, X, 2′+*2′, 6′′, 6c, 7s, 5′′′, 1p, 1′′′′.•The corresponding cyst stage is similar to Operculodinium israelianum and is named Operculodinium lapazense.•No yessotoxins were detected in the analyzed ten strains.