The toxic dinoflagellate Cochlodinium polykrikoides (Dinophyceae) produces resting cysts

Mapping the Distribution of Cysts from the Toxic Dinoflagellate Cochlodinium polykrikoides in Bloom-Prone Estuaries by a Novel Fluorescence In Situ Hybridization Assay

“…polykrikoides (a Cochlodinium sp. that looks like C. polykrikoides), which bear little resemblance to the cysts produced in cultures (10,27,28). Recently, Li et al (36) reported on the recovery of a cyst from Korean coastal waters that germinated into a C. polykrikoides cell, confirmed via large subunit ribosomal DNA (LSU rDNA) sequencing, that exhibited a morphology distinct from that given in all prior reports, with a cyst body that was covered by reticulate ornaments and spines.…”

“…esting cysts of dinoflagellates can be associated with genetic recombination, maintenance of blooms, termination of blooms, recurrence of annual blooms, resistance against unfavorable environmental conditions, protection from viruses, grazers, or parasite attacks, and geographical expansion of populations (1)(2)(3)(4)(5)(6)(7)(8)(9)(10). Resting cysts, therefore, play an important role in the ecology of harmful algal blooms (HABs) caused by dinoflagellates (8,11) and have been considered a fundamental attribute of dinoflagellate life cycles (12).…”

“…About 200 marine and freshwater dinoflagellates are known to produce resting cysts, a small number relative to the ϳ2,300 extant dinoflagellate species (5,11,13). More than 20 of these cyst-producing dinoflagellates are known to cause harmful algal blooms (HABs) (5), including Cochlodinium polykrikoides Margalef (10).…”

“…The initiation and development of C. polykrikoides blooms have been shown to be related to multiple factors, including stimulation by nutrients such as nitrogen and vitamins (18,19), mixotrophy (20), the production of extracellular toxins lethal to grazers (21)(22)(23), bacterial mutualism (24), and allelopathic effects on competing phytoplankton (25). Recently, definitive evidence of resting cyst production by North American clones of C. polykrikoides provided a mechanism to account for the recurrence of annual blooms in given locales as well as the global expansion of C. polykrikoides blooms during the past 2 decades (10).…”

“…Recently, Li et al (36) reported on the recovery of a cyst from Korean coastal waters that germinated into a C. polykrikoides cell, confirmed via large subunit ribosomal DNA (LSU rDNA) sequencing, that exhibited a morphology distinct from that given in all prior reports, with a cyst body that was covered by reticulate ornaments and spines. While C. polykrikoides resting cysts have been observed in culture (10), thus far, identifying these cysts in the field using traditional microscopic methods or via PCR has proven difficult and has resulted in a series of putatively falsepositive identifications (as reviewed in references 10 and 16).…”