Study of perkinsosis in the carpet shell clam Tapes decussatus in Galicia (NW Spain). I. Identification of the aetiological agent and in vitro modulationof zoosporulation by temperature and salinity

Diseases of Aquatic Organisms

Kimberly S. Reece¹  Antonio Villalba¹  Sandra M. Casas¹ 

关键词: Perkinsus atlanticus;    Tapes decussatus;    SSU rRNA gene;    ITS region;    Zoosporulation;    Ultrastructure;    Temperature;    Salinity;    Chlorine;   

DOI  :  10.3354/dao050051

学科分类：生物科学（综合）

来源: Inter-Research

【 摘 要 】

ABSTRACT: Morphological characters of zoosporulation stages and DNA sequence of the internal transcribed spacer (ITS) region and the small subunit ribosomal RNA (SSU rRNA) gene confirmed that the aetiological agent of perkinsosis in the clam Tapesdecussatus from Galicia (NW Spain) was Perkinsus atlanticus Azevedo, 1989. In vitro modulation by temperature and salinity of the zoosporulation of the parasite was studied. The optimum temperature range for zoosporulation was 19 to28°C. The temperature range allowing zoosporulation in vitro was 15 to 32°C, which is broader than previously reported (24 to 28°C) for P. atlanticus, and strongly suggests that zoospores can be produced in Galician Rías, where temperatureranges from 10 to 22°C. Prezoosporangia held at 10°C for 2 mo (similar to winter conditions in Galician waters) gave rise to viable zoospores after they were transferred to higher temperatures. This suggests that prezoosporangia could overwinter andzoosporulate in the next spring. Zoospores could survive for up to 22 and 14 d at 28 and 10°C, respectively. The optimum salinity range for zooporulation was 25 to 35‰. Zoospore production was abruptly reduced as salinity decreased. The lowestsalinity at which zoosporulation was observed was 10‰. The effectiveness of different chlorine concentrations and exposure lengths to kill prezoosporangia and zoospores was tested. No survival of free zoospores, free prezoosporangia andprezoosporangia included in gill tissue was observed after incubation for 1 h with 50, 200 and 3000 ppm of chlorine, respectively.

【 授权许可】

Unknown