title: Changes of paralytic shellfish toxins in gills and digestive glands of the cockle Cerastoderma edule under post-bloom natural conditions.
abstract: Concentrations of the paralytic shellfish toxins C1+2, C3+4, GTX5, GTX6, dcGTX2+3, dcSTX, dcNEO, GTX2+3, GTX1+4, STX and NEO were determined by LC-FLD in composite samples of digestive glands and gills of Cerastoderma edule cockle. The specimens were sampled in Aveiro lagoon, Portugal, under natural depuration conditions (days 0, 8, 12, 14, 19, 21 and 25) after exposure to a bloom of Gymnodinium catenatum. Individual paralytic shellfish toxins indicated different pathways of elimination and biotransformation in digestive gland and gills. Toxin concentrations in gills were lower than in digestive gland. Most of the quantified toxins in digestive gland decreased during the 25 days of observation according to negative exponential curves, and only GTX5, GTX6 and NEO showed slight irregularities with time. Concentrations of C1+2, C3+4 and dcGTX2+3 in gills decreased progressively, however GTX5, GTX6 and dcSTX showed pronounced increases. Higher concentrations of those toxins in days 8 and 12 in comparison to the initial value (day 0) indicate conversion of other toxins into GTX5, GTX6 and dcSTX during those periods. It appears that inter-conversion of toxins occurs as G. catenatum cells are retained in gills before being transferred to other compartments.
authors.affiliation: IPMA, Portuguese Institute for the Sea and Atmosphere, Rua Alfredo Magalhães Ramalho 6, 1495-006 Lisbon, Portugal.
authors.forename: Sara T
authors.initials: ST
authors.lastname: Costa
authors.affiliation: CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Rua dos Bragas 289, 4050-123 Porto, Portugal.
authors.forename: Carlos
authors.initials: C
authors.lastname: Vale
authors.affiliation: IPMA, Portuguese Institute for the Sea and Atmosphere, Rua Alfredo Magalhães Ramalho 6, 1495-006 Lisbon, Portugal; CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Rua dos Bragas 289, 4050-123 Porto, Portugal.
authors.forename: Joana
authors.initials: J
authors.lastname: Raimundo
authors.affiliation: CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Rua dos Bragas 289, 4050-123 Porto, Portugal; IPMA, Portuguese Institute for the Sea and Atmosphere, Av. 5 de Outubro, 8700-305 Olhão, Portugal.
authors.forename: Domitília
authors.initials: D
authors.lastname: Matias
authors.affiliation: IPMA, Portuguese Institute for the Sea and Atmosphere, Rua Alfredo Magalhães Ramalho 6, 1495-006 Lisbon, Portugal; CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Rua dos Bragas 289, 4050-123 Porto, Portugal. Electronic address: mjbotelho@ipma.pt.
authors.forename: Maria João
authors.initials: MJ
authors.lastname: Botelho
mesh_terms: D000818:Animals; D001711:Biotransformation; D049873:Cardiidae / Q000378:metabolism*; D004141:Dinoflagellida / Q000378:metabolism; D004784:Environmental Monitoring; D005880:Gills / Q000378:metabolism; D057097:Harmful Algal Bloom; D008387:Marine Toxins / Q000378:metabolism*; D011174:Portugal; D012758:Shellfish; D057096:Shellfish Poisoning; D014873:Water Pollutants / Q000378:metabolism*
chemical_list: D008387:Marine Toxins; D014873:Water Pollutants
keywords: Biotransformation; Cerastoderma edule; Depuration; Digestive gland; Gills; Paralytic shellfish toxins