Spatio-temporal patterns of perkinsosis in the Manila clam Ruditapes philippinarum from Arcachon Bay (SW France)
|Author(s)||Dang Cecile1, de Montaudouin Xavier1, Caill-Milly Nathalie2, Trumbic Zeljka1|
|Affiliation(s)||1 : Univ Bordeaux 1, CNRS, UMR 5805, EPOC,Stn Marine Arcachon, Arcachon, France.
2 : IFREMER, Lab Ressources Halieut Aquitaine, Anglet, France.
|Source||Diseases Of Aquatic Organisms (0177-5103) (Inter-research), 2010-09 , Vol. 91 , N. 2 , P. 151-159|
|WOS© Times Cited||18|
|Keyword(s)||Ruditapes philippinarum, Perkinsus sp., Arcachon Bay, Clam, Spatio-temporal variations, Disinfection, Infection|
Pathogens belonging to the genus Perkinsus infect many bivalve molluscan species around the world, including the Manila clam Ruditapes phihppinarum. We investigated the spatial distribution of this parasite at 34 stations throughout Arcachon Bay (SW France). Prevalence of perkinsosis was 93% and mean infection abundance was 96 x 10(3) cells g(-1) wet gill. Lowest mean abundances were found close to the Leyre River mouth and a significant negative correlation was observed between mean abundance and salinity. Perkinsosis was rare at the oceanic site where salinities and other environmental parameters were stable. A second aim of this study was to survey perkinsosis during annual cycles at 4 sites within Arcachon Bay. Prevalence and intensities (+/-SE) of the disease were high, on average between 70 and 100%, and 130 x 10(3) +/- 6.7 x 10(3) cells g(-1) wet gill. No seasonal cycle was evident. Clams were infected at 9 mm shell length and infection increased with clam size. The third objective was to determine the disinfection and infection kinetics through a 21 mo reciprocal transplantation between a nearly Perkinsus sp.-free area and a highly affected site. Disinfection appeared to be a very slow process and was similar at the site with favorable conditions for Perkinsus sp. as at the site with unfavorable conditions. Conversely, infection acquisition appeared to be episodic with spatially defined areas. Consequently, the overall lack of a clear seasonal infection pattern is interpreted as the combination of episodic infection events and slow disinfection kinetics.