Description of Pseudo-nitzschia cuspidata var. manzanillensis var. nov (Bacillariophyceae): morphology and molecular characterization of a variety from the central Mexican pacific

作者：Rivera Vilarelle Maria; Leticia Valdez Velazquez Laura; Isabel Quijano Scheggia Sonia

来源：Diatom Research, 2018, 33(1): 55-68.

DOI：10.1080/0269249X.2018.1426633

• Pseudo-nitzschia spp
• pseudo-cryptic species
• ITS1-5.8S-ITS2
• Pseudo-nitzschia cuspidata
• secondary structure of RNA

The diatoms of the genus Pseudo-nitzschia are of special interest due to their capacity to produce domoic acid, which is responsible for amnesic shellfish poisoning (ASP) in humans. Domoic acid is a neurotoxin that can cause devastating effects in the food web, especially in seabirds and marine mammals. Identification of Pseudo-nitzschia species is challenging since the morphological differences are difficult to distinguish in the light microscope, and even in SEM or TEM. In recent years, new molecular biology methods have been developed that allow us to differentiate between pseudo-cryptic or cryptic species. In this study, a new pseudo-cryptic taxon is described within the Pseudo-nitzschia/pseudodelicatissima complex, as a variety of P. cuspidata. Subtle morphological differences were found among our strains of P. cuspidata and other previously described strains of the P. pseudodelicatissima/cuspidata complex with respect to the poroids of the valvocopula. These differences were supported by phylogenetic analyses of ITS rDNA sequences. The existence of hemi-compensatory base changes in some of the strains indicates the presence of a separate clade, which is described as a new variety of P. cuspidata group. Domoic acid was not detected in the strains investigated in this study.

• 出版日期2018