title: Characterization and comparison of toxin-producing isolates of Dinophysis acuminata from New England and Canada.
abstract: Following the identification of the first toxic isolate of Dinophysis acuminata from the northwestern Atlantic, we conducted detailed investigations into the morphology, phylogeny, physiology, and toxigenicity of three isolates from three sites within the northeastern U.S./Canada region: Eel Pond and Martha's Vineyard, Massachusetts, and the Bay of Fundy. Another isolate, collected from the Gulf of Mexico, was grown under the same light, temperature, and prey conditions for comparison. Despite observed phenotypic heterogeneity, morphometrics and molecular evidence classified the three northwestern Atlantic isolates as D. acuminata Claparède & Lachmann, whereas the isolate from the Gulf of Mexico was morphologically identified as D. cf. ovum. Physiological and toxin analyses supported these classifications, with the three northwestern Atlantic isolates being more similar to each other with respect to growth rate, toxin profile, and diarrhetic shellfish poisoning (DSP) toxin content (okadaic acid + dinophysistoxin 1/cell) than they were to the isolate from the Gulf of Mexico, which had toxin profiles similar to those published for D. cf. ovum F. Schütt. The DSP toxin content, 0.01-1.8 pg okadaic acid (OA) + dinophysistoxin (DTX1) per cell, of the three northwestern Atlantic isolates was low relative to other D. acuminata strains from elsewhere in the world, consistent with the relative scarcity of shellfish harvesting closures due to DSP toxins in the northeastern U.S. and Canada. If this pattern is repeated with the analyses of more geographically and temporally dispersed isolates from the region, it would appear that the risk of significant DSP toxin outbreaks in the northwestern Atlantic is low to moderate. Finally, the morphological, physiological, and toxicological variability within D. acuminata may reflect spatial (and/or temporal) population structure, and suggests that sub-specific resolution may be helpful in characterizing bloom dynamics and predicting toxicity.
authors.affiliation: Ocean College, Zhejiang University, Hangzhou, 310058, China.|Biology Department and the Woods Hole Center for Oceans and Human Health, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, 02543, USA.
authors.forename: Mengmeng
authors.initials: M
authors.lastname: Tong
authors.affiliation: Biology Department and the Woods Hole Center for Oceans and Human Health, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, 02543, USA.|Virginia Institute of Marine Science, College of William and Mary, Gloucester Point, Virginia, 23062, USA.
authors.forename: Juliette L
authors.initials: JL
authors.lastname: Smith
authors.affiliation: Biology Department and the Woods Hole Center for Oceans and Human Health, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, 02543, USA.
authors.forename: Mindy
authors.initials: M
authors.lastname: Richlen
authors.affiliation: Fish and Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission, St Petersburg, Florida, 33701, USA.
authors.forename: Karen A
authors.initials: KA
authors.lastname: Steidinger
authors.affiliation: Biology Department and the Woods Hole Center for Oceans and Human Health, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, 02543, USA.
authors.forename: David M
authors.initials: DM
authors.lastname: Kulis
authors.affiliation: Division of Seafood Science and Technology, U.S. FDA, Dauphin Island, Alabama, 36528, USA.
authors.forename: Elie
authors.initials: E
authors.lastname: Fux
authors.affiliation: Biology Department and the Woods Hole Center for Oceans and Human Health, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, 02543, USA.
authors.forename: Donald M
authors.initials: DM
authors.lastname: Anderson
keywords: Diarrhetic Shellfish Poisoning; Dinophysis acuminata; Dinophysis acuminata complex; cox1; morphology; okadaic acid; pectenotoxins; peduncle