Infection of bryozoans by Tetracapsuloides bryosalmonae at sites endemic for salmonidproliferative kidney disease

Diseases of Aquatic Organisms

Sylvie Tops¹  Beth Okamura¹ 

关键词: Tetracapsuloides bryosalmonae;    Proliferative kidney disease;    Freshwater bryozoans;    Infection rates;    Cryptic stages;    Malacosporea;    Myxozoa;   

DOI  :  10.3354/dao057221

学科分类：生物科学（综合）

来源: Inter-Research

【 摘 要 】

ABSTRACT: Laboratory-reared colonies of the bryozoans Fredericella sultana and Plumatella fungosa were placed upstream of 2 fish farms endemic for salmonid proliferative kidney disease (PKD) to assess rates of infection of bryozoansby Tetracapsuloides bryosalmonae, the causative agent of PKD. Colonies were deployed in the field for 8 trial periods of 2 wk each throughout the summer of 2001. Following each trial, bryozoan colonies were maintained in laboratory culture for 28 dand were regularly monitored for infection by searching for sac stages of T. bryosalmonae. Infections were never identified by observations of sac stages, however positive PCR results and sequencing of cultured material confirmed that crypticinfections were present in colonies of both species deployed at one site. The possibility that PCR results reflected contamination of surfaces of bryozoans can be excluded, given the short period of spore viability of T. bryosalmonae. Highest ratesof infection occurred when 4 of 23 colonies of F. sultana and 1 of 12 colonies of P. fungosa were infected during the period 10 to 24 July. No infections were detected from mid-August to late October at this site. None of the colonies atthe other site became infected throughout the period of study. Our data provide the first estimates of infection rates of bryozoans by T. bryosalmonae. Additionally, they provide evidence that a cryptic stage can be maintained within bryozoan hostsfor a period of 4 to 6 wk.

【 授权许可】

Unknown