title: The occurrence of domoic acid linked to a toxic diatom bloom in a new potential vector: the tunicate Pyura chilensis (piure).
abstract: The tunicate Pyura chilensis (Molina, 1782); Phylum Chordata; Subphylum Urochordata; Class Ascidiacea, common local name "piure" or sea squirt; a filter-feeder (plankton and suspended particles) sessile species; may play an important role in monitoring domoic acid (DA) the principal toxic component of Amnesic Shellfish Poisoning (ASP). Significant DA concentrations have been determined in tunicate samples, collected during a recent ASP outbreak in Bahía Inglesa, an important scallop (Argopecten purpuratus) farming area. Several infaunal species were tested for the presence of DA, in addition to the usual scallop monitoring programme. DA was found at sub-toxic levels in filtering bivalves such as mussels (Mytilus chilensis), large mussels (Aulacomya ater) and clams (Protothaca thaca) (6.4, 5.4 and 4.7 microg DA/g tissue respectively). Of particular interest was the observation of significant accumulations of toxic Pseudo-nitzschia sp. diatoms in the internal siphon and atrium spaces of the tunicate. Toxin distribution within major tunicate organs was heterogeneous with 8.7-15.5 microg DA/g in edible tissues, 14.9-17.9 microg DA/g in the fecal material and 13.6-32.7 microg DA/g in the gut content. DA was determined by HPLC-UV and confirmed by diode-array detection and LC-MS/MS analysis. This is the first report of the presence of DA in a tunicate that is regularly consumed by coastal populations. These results confirm the need to include these organisms in sanitation programs for marine toxins.
authors.affiliation: Marine Toxins Laboratory, Physiology and Biophysics Program, Biomedical Sciences Institute, Faculty of Medicine, University of Chile, Independencia 1027, Santiago, Chile. amlopez@med.uchile.cl
authors.forename: Américo
authors.initials: A
authors.lastname: López-Rivera
authors.forename: Maricela
authors.initials: M
authors.lastname: Pinto
authors.forename: Andrea
authors.initials: A
authors.lastname: Insinilla
authors.forename: Benjamín
authors.initials: B
authors.lastname: Suárez Isla
authors.forename: Eduardo
authors.initials: E
authors.lastname: Uribe
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Alvarez
authors.forename: Mary
authors.initials: M
authors.lastname: Lehane
authors.forename: Ambrose
authors.initials: A
authors.lastname: Furey
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: James
mesh_terms: D000818:Animals; D017377:Diatoms / Q000254:growth & development*; D007608:Kainic Acid / Q000031:analogs & derivatives* / Q000032:analysis / Q000633:toxicity; D014561:Urochordata
chemical_list: C012301:domoic acid; D007608:Kainic Acid