Life cycle, morphology and phylogeny of species of Fragilidium Balech from west Iberia
Published:January 01, 2013
A. Amorim, V. Veloso, F Rodríguez, S. Fraga, 2013. "Life cycle, morphology and phylogeny of species of Fragilidium Balech from west Iberia", Biological and Geological Perspectives of Dinoflagellates, J. M. Lewis, F. Marret, L. R. Bradley
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Specimens belonging to the mixotrophic genus Fragilidium were isolated from coastal waters of west Iberia (NE Atlantic). Based on plate morphology and large subunit ribosomal DNA (LSU rDNA) sequences two species were identiﬁed: F. subglobosum and F. cf. duplocampanaeforme. The life cycle is similar in both species. The asexual cycle is characterized by an alternation between a thecate motile stage and a reproductively active coccoid stage. The sexual cycle is characterized by heterogamous anisogamy and includes a sexual benthic hypnozygote. The ﬁrst apical plate in vegetative cells does not touch the apical pore plate while in gametes it does, conﬁrming in Fragilidium the homology of what is frequently referred to as the ﬁrst pre-cingular with the ﬁrst apical plate in Gonyaulacales. Both species were observed to prey on Ceratium horridum. Molecular phylogenetic analyses with strains isolated from other geographical areas and Fragilidium gene sequences available in GenBank identiﬁed three different clades: one comprising F. subglobosum from the type locality and strains from Iberian waters; a second comprising the morphological species F. cf. duplocampanaeforme from Iberia and other strains from NE Atlantic, SE Atlantic and the south Paciﬁc; and a third with an unassigned species from the SE Atlantic.
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Biological and Geological Perspectives of Dinoflagellates
This volume provides an overview of current research on fossil and modern dinoflagellates, as well as highlighting research areas for future collaboration, following the DINO9 International Conference in Liverpool. The volume is organized into four themes, with a review paper for each theme written by the key-note speaker. Each theme also includes a future research foci note following discussion during the conference. The contributions are organized into the following sections: environmental change, ecology/palaeoecology, life cycles and diversity, and stratigraphy and evolution. Also included are notes from two workshops: culture experiments and dinocysts as palaeoceanographic tracers. This volume will be of interest to both the biological and Micropalaeontological communities.