Towards an Ecological Understanding of Dinoflagellate Cyst Functions

Abstract

The life cycle of many dinoflagellates includes at least one nonflagellated benthic stage (cyst). In the literature, the different types of dinoflagellate cysts are mainly defined based on morphological (number and type of layers in the cell wall) and functional (long- or short-term endurance) differences. These characteristics were initially thought to clearly distinguish pellicle (thin-walled) cysts from resting (double-walled) dinoflagellate cysts. The former were considered short-term (temporal) and the latter long-term (resting) cysts. However, during the last two decades further knowledge has highlighted the great intricacy of dinoflagellate life histories, the ecological significance of cyst stages, and the need to clarify the functional and morphological complexities of the different cyst types. Here we review and, when necessary, redefine the concepts of resting and pellicle cysts, examining both their structural and their functional characteristics in the context of the life cycle strategies of several dinoflagellate species.

Development, morphological characteristics and viability of temporary cysts ofPyrodinium bahamensevar.compressum(Dinophyceae)in vitro

“…motility, morphology and cell division) was also observed in cultures in 13ºC by day 10. Previous studies have shown that in some species, temporary cysts are capable of division forming socalled division cysts (Bravo & Figueroa, 2014) but these were not actually observed in this study and possible explanations are still unclear. We also observed that a temperature regime of 30°C induced pellicle formation, indicating that temperature stress (both low and high) can cause transformation but with different effects on cell viability and integrity.…”

Seasonal and Interannual Changes in Ciliate and Dinoflagellate Species Assemblages in the Arctic Ocean (Amundsen Gulf, Beaufort Sea, Canada)

“…Earlier microscopy (Lovejoy et al, 1993;Okolodkov and Dodgeb, 1996;Jiang et al, 2013) and clone library studies using longer 18S rRNA sequences (Bachy et al, 2011;Lovejoy and Potvin, 2011) have also highlighted the differences between SCM and surface communities over the Arctic. Within the two water masses, communities separated by template suggests a pool of historic DNA, which could include dormant or less active stages, e.g., cysts (Verni and Rosati, 2011;Bravo and Figueroa, 2014), advected non-active species (Lovejoy and Potvin, 2011), preserved free DNA, or non-living material in marine snow (Nielsen et al, 2007;Boere et al, 2011). All of these sources can be transported by currents and persist over long distances (Heiskanen, 1993;Brocks and Banfield, 2009).…”

Analysis of the hydrographic conditions and cyst beds in the San Jorge Gulf, Argentina, that favor dinoflagellate population development including toxigenic species and their toxins

“…Cyst dormancy is an important stage in the life cycle of dinoflagellates and determines bloom seasonality. However, the relationship between this endogenous (genetic) clock and seasonality is not well understood (Bravo and Figueroa, 2014). Motile dinoflagellates and even temporary cysts are often quickly degraded by bacterial action after death.…”