Determination of Coscinodiscus cf. granii biovolume by confocal microscopy: Comparison of calculation models

Leonilde Roselli, Elena Stanca, Francesco Paparella, Annunziata Mastrolia, Alberto Basset

Research output: Contribution to journalArticle

Abstract

Biovolume is commonly used as a size descriptor in the study of phytoplankton ecology. Usually, biovolume is not measured directly but is obtained from a standardized set of geometric models based on linear dimensions measured by light microscopy. This commonly used method allows visualization and measurement in two dimensions (2D) yielding no information at all on the third dimension of phytoplankton cells. Inaccurate biovolume assessment resulting from geometric approximation leads to erroneous interpretation of eco-physiological processes and morpho-functional traits. Here, we use confocal microscopy coupled with an image analysis system (NIS Elements AR software, Nikon) to determine directly shape and biovolume by means a 3D reconstruction of Coscinodiscus cf. granii specimens. We evaluate the accuracy of current methods by comparing the results obtained using geometric models with direct biovolume and shape. We find that calculation of biovolume by approximation to geometric models (cylindrical and complex shapes) leads to a significant overestimation with respect to direct volume. We also propose a data-driven formula for calculating the biovolume of Coscinodiscus cf. granii specimens based on diameter or other linear measurements.

Original languageEnglish (US)
Pages (from-to)135-145
Number of pages11
JournalJournal of Plankton Research
Volume35
Issue number1
DOIs
StatePublished - Jan 1 2013

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Keywords

  • 3D-imaging
  • Biovolume
  • Confocal microscopy
  • Coscinodiscus cf. granii

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Aquatic Science
  • Ecology

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