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Hemolymph chemistry and histopathological changes in Pacific oysters (Crassostrea gigas) in response to low salinity stress


Knowles, G and Handlinger, J and Jones, B and Moltschaniwskyj, N, Hemolymph chemistry and histopathological changes in Pacific oysters (Crassostrea gigas) in response to low salinity stress, Journal of Invertebrate Pathology, 121 pp. 78-84. ISSN 0022-2011 (2014) [Refereed Article]

Copyright Statement

Copyright 2014 Elsevier Inc.

DOI: doi:10.1016/j.jip.2014.06.013


This study described seasonal differences in the histopathological and hemolymph chemistry changes in different family lines of Pacific oysters, Crassostrea gigas, in response to the stress of an abrupt change to low salinity, and mechanical grading. The most significant changes in pallial cavity salinity, hemolymph chemistry and histopathological findings occurred in summer at low salinity. In summer (water temperature 18 °C) at low salinity, 9 (25.7% of full salinity), the mean pallial cavity salinity in oysters at day 3 was 19.8 ± 1.6 (SE) and day 10 was 22.8 ± 1.6 (SE) lower than oysters at salinity 35. Associated with this fall in pallial cavity salinity, mean hemolymph sodium for oysters at salinity 9 on day 3 and 10 were 297.2 mmol/L ± 20(SE) and 350.4 mmol/L ± 21.3(SE) lower than oysters at salinity 35. Similarly mean hemolymph potassium in oysters held at salinity 9 at day 3 and 10 were 5.6 mmol/L ± 0.6(SE) and 7.9 mmol/L ± 0.6 (SE) lower than oysters at salinity 35. These oysters at low salinity had expanded intercellular spaces and significant intracytoplasmic vacuolation distending the cytoplasm of epithelial cells in the alimentary tract and kidney and hemocyte infiltrate (diapedesis) within the alimentary tract wall. In contrast, in winter (water temperature 8 °C) oyster mean pallial cavity salinity only fell at day 10 and this was by 6.0 ± 0.6 (SE) compared to that of oysters at salinity 35. There were limited histopathological changes (expanded intercellular spaces and moderate intracytoplasmic vacuolation of renal epithelial cells) in these oysters at day 10 in low salinity. Mechanical grading and family line did not influence the oyster response to sudden low salinity. These findings provide additional information for interpretation of non-lethal, histopathological changes associated with temperature and salinity variation.

Item Details

Item Type:Refereed Article
Keywords:Pacific oyster, salinity, grading, kidney, stomach, digestive gland
Research Division:Biological Sciences
Research Group:Zoology
Research Field:Invertebrate biology
Objective Division:Animal Production and Animal Primary Products
Objective Group:Fisheries - wild caught
Objective Field:Wild caught edible molluscs
UTAS Author:Moltschaniwskyj, N (Associate Professor Natalie Moltschaniwskyj)
ID Code:98911
Year Published:2014
Web of Science® Times Cited:19
Deposited By:Sustainable Marine Research Collaboration
Deposited On:2015-03-06
Last Modified:2017-11-03

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