title: Genetic and toxinological characterization of North Atlantic strains of the dinoflagellate Ostreopsis and allelopathic interactions with toxic and non-toxic species from the genera Prorocentrum, Coolia and Gambierdiscus.
abstract: The genus Ostreopsis includes several toxic species that can develop blooms in benthic ecosystems, with potential harmful consequences for human health and marine invertebrates. Despite of this, little is known about the allelopathic interactions between these organisms and other co-occurring microalgae that exploit similar spatial and nutrient resources in benthic ecosystems. The aim of this study was to follow these interactions in cultures of two Ostreopsis ribotypes with different toxin profiles (O. cf. ovata contained ovatoxins-a, b, c and e, while only ovatoxin-d was found in O .sp. "Lanzarote-type"), mixed with species of three benthic dinoflagellate genera (Coolia, Prorocentrum and Gambierdiscus), isolated from the same area (North East Atlantic, Canary Islands). In a first experiment, the potential allelopathic effects on growth rates were followed, in mixed cultures of Coolia monotis (a non toxic species) exposed to the clarified medium and to cells of O. sp."Lanzarote-type" and O. cf. ovata. Growth delayed in C. monotis was observed specially in clarified medium, while the O. sp. "Lanzarote-type" strain attained much lower densities in mixed cultures. In a second experiment, we examined the potential effects of clarified media from O. sp."Lanzarote-type" and O. cf. ovata on the adherence capacity in two toxic species (Prorocentrum hoffmannianum and Gambierdiscus excentricus). Contrasting effects were found: a significant increase of adherence capacity in P. hoffmannianum vs attachment decline in G. excentricus, that experienced also severe deleterious effects (cell lysis). Our results suggest the existence of weak to moderate allelopathic interactions between the studied organisms, although the outcome is dependent on the species involved.
authors.affiliation: Instituto Español de Oceanografia (IEO), Centro Oceanográfico de Vigo, Subida a Radio Faro 50-52, Cabo Estay, Canido, 36390 Vigo, Spain. Electronic address: maria.garcia@vi.ieo.es.
authors.forename: María
authors.initials: M
authors.lastname: García-Portela
authors.affiliation: Instituto de Investigaciones Marinas, CSIC (UA Microalgas Nocivas CSIC-IEO), Eduardo Cabello, 6, 36208 Vigo, Spain. Electronic address: pilarriobo@nautilus.iim.csic.es.
authors.forename: Pilar
authors.initials: P
authors.lastname: Riobó
authors.affiliation: Instituto de Investigaciones Marinas, CSIC (UA Microalgas Nocivas CSIC-IEO), Eduardo Cabello, 6, 36208 Vigo, Spain. Electronic address: jose.franco@vi.ieo.es.
authors.forename: José Mariano
authors.initials: JM
authors.lastname: Franco
authors.affiliation: Departamento de Oceanografía, Instituto de Investigaciones Marinas (CSIC), Eduardo Cabello, 6, 36208 Vigo, Spain. Electronic address: banhuelos@iim.csic.es.
authors.forename: Rosa Mª
authors.initials: RM
authors.lastname: Bañuelos
authors.affiliation: Instituto Español de Oceanografia (IEO), Centro Oceanográfico de Vigo, Subida a Radio Faro 50-52, Cabo Estay, Canido, 36390 Vigo, Spain. Electronic address: francisco.rodriguez@vi.ieo.es.
authors.forename: Francisco
authors.initials: F
authors.lastname: Rodríguez
mesh_terms: D064089:Allelopathy; D059001:Aquatic Organisms; D001267:Atlantic Ocean; D004141:Dinoflagellida / Q000737:chemistry* / Q000235:genetics / Q000502:physiology*; D008387:Marine Toxins / Q000633:toxicity*; D058086:Microalgae / Q000502:physiology*; D013030:Spain; D013045:Species Specificity
chemical_list: D008387:Marine Toxins
keywords: Adhesion.; Allelopathy; Inhibitory effects; Interespecific effects; Ostreopsis; Ovatoxins; PTXs