Effects of Alexandrium minutum exposure upon physiological and hematological variables of diploid and triploid oysters, Crassostrea gigas

Jan 5, 2010Aquatic toxicology (Amsterdam, Netherlands)

Effects of Alexandrium minutum on body and blood measures of normal and triploid Pacific oysters

AI simplified

Circadian Biology on OpenScience ↗PubMed ↗DOI ↗

Abstract

Triploid oysters accumulated approximately twice the levels of Paralytic Shellfish Toxins compared to diploid oysters when exposed to the dinoflagellate, Alexandrium minutum.

Exposure to A. minutum resulted in lower phenoloxidase activity in hemocytes of diploid and triploid oysters during early maturation stages.
In ripe diploid oysters, the phenoloxidase activity was higher compared to those exposed to A. minutum in the May experiment.
Granulocytes from A. minutum-exposed oysters produced more reactive oxygen species in April, but production decreased in May.
Significant decreases in free fatty acids, monoacylglycerols, and diacylglycerols were observed in the digestive glands of oysters exposed to A. minutum.
The ratio of reserve lipids to structural lipids decreased in oysters due to A. minutum exposure, with variations observed based on maturation stage and ploidy.

AI simplified

The effects of an artificial bloom of the toxin-producing dinoflagellate, Alexandrium minutum, upon physiological parameters of the Pacific oyster, Crassostrea gigas, were assessed. Diploid and triploid oysters were exposed to cultured A. minutum and compared to control diploid and triploid oysters fed T. Isochrysis. Experiments were repeated twice, in April and mid-May 2007, to investigate effects of maturation stage on oyster responses to A. minutum exposure. Oyster maturation stage, Paralytic Shellfish Toxin (PST) accumulation, as well as several digestive gland and hematological variables, were assessed at the ends of the exposures. In both experiments, triploid oysters accumulated more PSTs (approximately twice) than diploid oysters. Significant differences, in terms of phenoloxidase activity (PO) and reactive oxygen species (ROS) production of hemocytes, were observed between A. minutum-exposed and non-exposed oysters. PO in hemocytes was lower in oysters exposed to A. minutum than in control oysters in an early maturation stage (diploids and triploids in April experiment and triploids in May experiment), but this contrast was reversed in ripe oysters (diploids in May experiment). In the April experiment, granulocytes of oysters exposed to A. minutum produced more ROS than those of control oysters; however, in the May experiment, ROS production of granulocytes was lower in A. minutum-exposed oysters. Moreover, significant decreases in free fatty acid, monoacylglycerol, and diacylglycerol contents in digestive glands of oysters exposed to A. minutum were observed. Concurrently, the ratio of reserve lipids (triacylglycerol, ether glycerides and sterol esters) to structural lipids (sterols) decreased upon A. minutum exposure in both experiments. Also, several physiological responses to A. minutum exposure appeared to be modulated by maturation stage as well as ploidy of the oysters.

Full Text

Full text is available at the source.

View full text (XML) ↗View full text ↗

Effects of Alexandrium minutum exposure upon physiological and hematological variables of diploid and triploid oysters, Crassostrea gigas

Abstract

Full Text

You found one interesting study. We’ll send the next 7.

what lands in your inbox each week:

Recent issues from the circadian biology brief

Abstract

Full Text

Related papers

You found one interesting study. We’ll send the next 7.

what lands in your inbox each week:

Recent issues from the circadian biology brief