title: Morphological variation and phylogenetic analysis of the dinoflagellate Gymnodinium aureolum from a tributary of Chesapeake Bay.
abstract: Cultures of four strains of the dinoflagellate Gymnodinium aureolum (Hulburt) G. Hansen were established from the Elizabeth River, a tidal tributary of the Chesapeake Bay, USA. Light microscopy, scanning electron microscopy, nuclear-encoded large sub-unit rDNA sequencing, and culturing observations were conducted to further characterize this species. Observations of morphology included: a multiple structured apical groove; a peduncle located between the emerging points of the two flagella; pentagonal and hexagonal vesicles on the amphiesma; production and germination of resting cysts; variation in the location of the nucleus within the center of the cell; a longitudinal ventral concavity; and considerable variation in cell width/length and overall cell size. A fish bioassay using juvenile sheepshead minnows detected no ichthyotoxicity from any of the strains over a 48-h period. Molecular analysis confirmed the dinoflagellate was conspecific with G. aureolum strains from around the world, and formed a cluster along with several other Gymnodinium species. Morphological evidence suggests that further research is necessary to examine the relationship between G. aureolum and a possibly closely related species Gymnodinium maguelonnense.
authors.affiliation: Marine Science Research Center, Stony Brook University, Stony Brook, NY 11794-1700, USA.
authors.forename: Ying Zhong
authors.initials: YZ
authors.lastname: Tang
authors.forename: Todd A
authors.initials: TA
authors.lastname: Egerton
authors.forename: Lesheng
authors.initials: L
authors.lastname: Kong
authors.forename: Harold G
authors.initials: HG
authors.lastname: Marshall
mesh_terms: D000818:Animals; D003530:Cyprinidae / Q000469:parasitology; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D004141:Dinoflagellida / Q000145:classification* / Q000235:genetics* / Q000648:ultrastructure; D005393:Fish Diseases / Q000469:parasitology; D005618:Fresh Water / Q000469:parasitology*; D008853:Microscopy; D008855:Microscopy, Electron, Scanning; D008969:Molecular Sequence Data; D015388:Organelles / Q000648:ultrastructure; D010273:Parasitic Diseases, Animal; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid; D014481:United States
chemical_list: D016054:DNA, Protozoan; D004275:DNA, Ribosomal