Marine diatoms from Buenos Aires coastal waters (Argentina). IV. Rhizosolenia s. str., Neocalyptrella, Pseudosolenia, Proboscia

Abstract

I. Sunesen & E.A. Sar 2007. Marine diatoms from Buenos Aires coastal waters (Argentina). IV. Rhizosolenia s. str., Neocalyptrella, Pseudosolenia, Proboscia. Phycologia 46: 628–643. DOI: 10.2216/07-13.1

The present paper describes the morphology, taxonomy, and distribution of species belonging to the diatom genera Rhizosolenia s. str., Neocalyptrella, Pseudosolenia and Proboscia, found in the marine coastal waters of Buenos Aires Province, Argentina. The phytoplankton samples were collected from October 1994 to September 2000 at seven locations and were analyzed by light and scanning electron microscopy. Rhizosolenia antennata f. antennata, R. bergonii, R. hyalina, R. imbricata, R. setigera f. setigera, R. setigera f. pungens, Neocalyptrella robusta, Pseudosolenia calcar-avis, Proboscia alata and P. indica were studied and compared with allied taxa. Morphology of the frustule and of the resting spore of R. setigera, which is considered by some authors incerta sedis, shows that this species might be included into the genus Rhizosolenia s. str. Rhizosolenia hyalina is reported for the first time from Argentinean coastal waters. R. setigera f. setigera, R. setigera f. pungens, P. alata, and P. calcar-avis, cited as harmful non-toxigenic taxa in other geographical areas, were never associated with harmful events in the study area.

Key Words::

• Diatoms
• Harmful species
• Rhizosolenia s. str.
• Neocalyptrella
• Pseudosolenia
• Proboscia

ACKNOWLEDGMENTS

We thank Dr. Silvia Sala for improving our paper and Dr. Nora Maidana for critically analysing the manuscript. Corrections made by Dr. Marina Potapova and two anonymous reviewers greatly improved our manuscript. The electron microscopy was done in the Servicio de Microscopía Electrónica of the Facultad de Ciencias Naturales y Museo. The research was supported by grants from the CONICET, PIP 0525/98 and PIP 5312/05.