The alternation of different morphotypes in the seasonal cycle of the toxic diatom Pseudo-nitzschia galaxiae

By F. Cerino, L. Orsini, D. Sarno, C. Dell’Aversano, L. Tartaglione, Adriana Zingone. 2005

123 citations recorded by the source corpus.

The marine diatom Pseudo-nitzschia galaxiae Lundholm et Moestrup has been recently described from Mexican and Australian plankton. In this paper, we illustrate the considerable morphological variability of the species in the Mediterranean Sea and present first evidence of its toxicity. In addition to lanceolate cells 25–41 m long, which fit the original description of the species, markedly larger ( 10m) specimens are commonly recorded. Cells of the largest size have almost parallel valve margins, while smaller specimens have extremely short rostrate ends and do not form colonies. Despite remarkable differences in shape and size, the typical ultrastructure of the species was observed for the different size classes in culture and in natural samples. In culture, cell length decreased at a rate of 1.1–2.1 m per month. Liquid chromatography–mass spectrometry (LC–MS) analyses revealed the presence of domoic acid (DA) at very low levels in two of seven strains analyzed. LSU rDNA analysis confirmed the identity of the species and showed a very low genetic variability for the strains from the Gulf of Naples, with no relationships with size and overall shape of the cells. A relatively high number (53) of Pseudo-nitzschiasequences were considered in the phylogenetic analysis, yet the relationships among species remain unclear, probably in relation with a recent speciation process in the genus. In natural samples, P. galaxiae populations of different cell sizes occurred at different times over the year, with smaller cells found in winter and early spring, and medium and larger cells peaking in late spring–summer. The maximum concentration value in the Gulf of Naples was recorded in May 1985 (9.4 × 10 6 cells l −1 ). From the analysis of a high number of both natural and culture samples, it is concluded that size and shape variations are indicative of different stages of the life cycle of P. galaxiae, which exhibit a synchronized and seasonal occurrence at the interannual scale. © 2004 Elsevier B.V. All rights reserved.

Subfields: Ecology, Environmental Chemistry, Oceanography

View Paper: https://www.semanticscholar.org/paper/a893e1fe17b8ad8314b4c801fc19ecbc6371cc25

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Ecology

1. E. Garcés
2. A. Penna
3. Magda Vila
4. E. Clavero
5. D. D’Alelio
6. Nina Lundholm
7. M. Giacobbe
8. Marina Montresor

In Environmental Chemistry

1. Stephen Bates
2. V. Trainer
3. Nina Lundholm
4. W. Cochlan
5. H. Hégaret
6. P. Soudant
7. A. Lelong
8. Anne E. Thessen

In Oceanography

1. Stephen Bates
2. V. Trainer
3. Nina Lundholm
4. Marina Montresor
5. H. Hégaret
6. P. Soudant
7. A. Lelong
8. E. Garcés

Citations in the corpus

• LIFE CYCLE, SIZE REDUCTION PATTERNS, AND ULTRASTRUCTURE OF THE PENNATE PLANKTONIC DIATOM PSEUDO‐NITZSCHIA DELICATISSIMA (BACILLARIOPHYCEAE) 1 (2005, background): “…morphological variation has been described for Pseudo-nitzschia galaxiae Lundholm and Moestrup, where longer cells are linear, mid-sized cells are lanceolate with rostrate ends, and the smallest cells have an almost oval outline with tapered ends (Lundholm and Moestrup 2002, Cerino et al. 2005).”
• Pseudo-nitzschia physiological ecology, phylogeny, toxicity, monitoring and impacts on ecosystem health (2012, background): “The three morphotypes bloom at different times of the year (Cerino et al., 2005).”
• INTER‐ AND INTRASPECIFIC VARIATION OF THE PSEUDO‐NITZSCHIA DELICATISSIMA COMPLEX (BACILLARIOPHYCEAE) ILLUSTRATED BY RRNA PROBES, MORPHOLOGICAL DATA AND PHYLOGENETIC ANALYSES 1 (2006, background): “The strain 20-02 from Gulf of Naples, Italy was identical to P. dolorosa with respect to both morphology and sequence data of ITS1, 5.8S and ITS of rDNA (accession number AY519275) (Orsini et al. 2004).”
• The use of partial cox1, rbcL and LSU rDNA sequences for phylogenetics and species identification within the Nitzschia palea species complex (Bacillariophyceae) (2010, background): “Amato et al , 2007 ; Cerino et al , 2005 ; Evans et al , 2007 , 2008 ), especially if taken together, and they deserve further consideration as molecular identifiers (barcodes), although rbc L, if used in its entirety, is over-long (c.”
• Monitoring of HAB species in the Mediterranean Sea through molecular methods (2006, background): “Nevertheless, until now, ASP production was found and associated only with Pseudo-nitzschia multistriata (Orsini et al., 2002) and Pseudo-nitzschia galaxiae (Cerino et al., 2005) strains isolated from the Gulf of Naples, Italy.”
• On the presence of Pseudo-nitzschia calliantha Lundholm, Moestrup et Hasle and Pseudo-nitzschia delicatissima (Cleve) Heiden in the Southern Adriatic Sea (Mediterranean Sea, Italy) (2005, background): “galaxiae distribution in Italian waters (Cerino et al., 2005) would indicate that the last designation is highly likely to be correct.”
• Pseudo-nitzschia (Bacillariophyceae) species, domoic acid and amnesic shellfish poisoning: revisiting previous paradigms (2012, methodology): “Often, the above groupings on the basis of cell width are consistent with those shown in phylogenetic trees (e.g. Cerino et al. 2005).”