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Physiological responses of Manila clams Venerupis (=Ruditapes) philippinarum with varying parasite Perkinsus olseni burden to toxic algal Alexandrium ostenfeldii exposure.
- Source :
-
Aquatic toxicology (Amsterdam, Netherlands) [Aquat Toxicol] 2014 Sep; Vol. 154, pp. 27-38. Date of Electronic Publication: 2014 May 14. - Publication Year :
- 2014
-
Abstract
- Manila clam stock from Arcachon Bay, France, is declining, as is commercial harvest. To understand the role of environmental biotic interactions in this decrease, effects of a toxic dinoflagellate, Alexandrium ostenfeldii, which blooms regularly in Arcachon bay, and the interaction with perkinsosis on clam physiology were investigated. Manila clams from Arcachon Bay, with variable natural levels of perkinsosis, were exposed for seven days to a mix of the nutritious microalga T-Iso and the toxic dinoflagellate A. ostenfeldii, a producer of spirolides, followed by seven days of depuration fed only T-Iso. Following sacrifice and quantification of protozoan parasite Perkinsus olseni burden, clams were divided into two groups according to intensity of the infection ("Light-Moderate" and "Moderate-Heavy"). Hemocyte and plasma responses, digestive enzyme activities, antioxidant enzyme activities in gills, and histopathological responses were analyzed. Reactive oxygen species (ROS) production in hemocytes and catalase (CAT) activity in gills increased with P. olseni intensity of infection in control clams fed T-Iso, but did not vary among A. ostenfeldii-exposed clams. Exposure to A. ostenfeldii caused tissue alterations associated with an inflammatory response and modifications in hemocyte morphology. In the gills, superoxide dismutase (SOD) activity decreased, and an increase in brown cell occurrence was seen, suggesting oxidative stress. Observations of hemocytes and brown cells in tissues during exposure and depuration suggest involvement of both cell types in detoxication processes. Results suggest that exposure to A. ostenfeldii disrupted the pro-/anti-oxidant response of clams to heavy P. olseni intensity. In addition, depressed mitochondrial membrane potential (MMP) in hemocytes of clams exposed to A. ostenfeldii suggests that mitochondrial functions are regulated to maintain homeostasis of digestive enzyme activity and condition index.<br /> (Copyright © 2014 Elsevier B.V. All rights reserved.)
- Subjects :
- Animals
Bivalvia enzymology
Bivalvia metabolism
Enzyme Activation drug effects
France
Gills drug effects
Hemocytes drug effects
Marine Toxins analysis
Marine Toxins metabolism
Mitochondria drug effects
Oxidoreductases metabolism
Parasite Load
Reactive Oxygen Species
Spiro Compounds analysis
Spiro Compounds metabolism
Water Pollutants, Chemical
Alveolata physiology
Bivalvia drug effects
Bivalvia parasitology
Dinoflagellida chemistry
Marine Toxins toxicity
Spiro Compounds toxicity
Subjects
Details
- Language :
- English
- ISSN :
- 1879-1514
- Volume :
- 154
- Database :
- MEDLINE
- Journal :
- Aquatic toxicology (Amsterdam, Netherlands)
- Publication Type :
- Academic Journal
- Accession number :
- 24858898
- Full Text :
- https://doi.org/10.1016/j.aquatox.2014.05.002