title: Contrasting physiological responses of two populations of the razor clam Tagelus dombeii with different histories of exposure to paralytic shellfish poisoning (PSP).
abstract: This study describes the physiological performance of two populations of the razor clam Tagelus dombeii from two geographic areas with different histories of exposure to paralytic shellfish poisoning (PSP) linked to the toxic dinoflagellate Alexandrium catenella. Clams from Melinka-Aysén, which are frequently exposed to PSP, were not affected by the presence of toxins in the diet. However, clams from Corral-Valdivia, which have never been exposed to PSP, exhibited significantly reduced filtration activity and absorption, affecting the energy allocated to scope for growth (SFG). Ammonia excretion and oxygen uptake were not affected significantly by the presence of A. catenella in the diet. Measurements of energy acquisition and expenditure were performed during a 12-day intoxication period. According to three-way repeated measure ANOVAs, the origin of the clams had a highly significant effect on all physiological variables, and the interaction between diet and origin was significant for the clearance and absorption rates and for the scope for growth. The scope for growth index showed similar positive values for both the toxic and non-toxic individuals from the Melinka-Aysén population. However, it was significantly reduced in individuals from Corral-Valdivia when exposed to the diet containing A. catenella. The absence of differences between the physiological response of the toxic and non-toxic clams from Melinka-Aysén may be related to the frequent presence of A. catenella in the environment, indicating that this bivalve does not suffer negative consequences from PSP. By contrast, A. catenella has a negative effect on the physiological performance, primarily on the energy gained from the environment, on T. dombeii from Corral-Valdivia. This study supports the hypothesis that the history of PSP exposure plays an important role in the physiological performance and fitness of filter feeding bivalves.
authors.affiliation: Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Chile.
authors.forename: Jorge M
authors.initials: JM
authors.lastname: Navarro
authors.affiliation: Escuela de Acuicultura, Universidad Católica de Temuco, Temuco, Chile.
authors.forename: Katerina
authors.initials: K
authors.lastname: González
authors.affiliation: Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Chile.
authors.forename: Barbara
authors.initials: B
authors.lastname: Cisternas
authors.affiliation: Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Chile.
authors.forename: Jorge A
authors.initials: JA
authors.lastname: López
authors.affiliation: Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Chile.
authors.forename: Oscar R
authors.initials: OR
authors.lastname: Chaparro
authors.affiliation: Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Valdivia, Chile.
authors.forename: Cristian J
authors.initials: CJ
authors.lastname: Segura
authors.affiliation: Laboratorio de Toxinas Marinas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.
authors.forename: Marco
authors.initials: M
authors.lastname: Córdova
authors.affiliation: Laboratorio de Toxinas Marinas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.
authors.forename: Benjamín
authors.initials: B
authors.lastname: Suárez-Isla
authors.affiliation: Instituto de Investigaciones Marinas, Consejo Superior de Investigaciones Científicas, Vigo, España.
authors.forename: María J
authors.initials: MJ
authors.lastname: Fernandez-Reiriz
authors.affiliation: Instituto de Investigaciones Marinas, Consejo Superior de Investigaciones Científicas, Vigo, España.
authors.forename: Uxio
authors.initials: U
authors.lastname: Labarta
mesh_terms: D000641:Ammonia / Q000378:metabolism; D000818:Animals; D049872:Bivalvia / Q000187:drug effects / Q000502:physiology*; D004141:Dinoflagellida; D008387:Marine Toxins / Q000633:toxicity*; D010101:Oxygen Consumption / Q000187:drug effects / Q000502:physiology; D057096:Shellfish Poisoning
chemical_list: D008387:Marine Toxins; D000641:Ammonia