Journal of Invertebrate Pathology 83 (2003) 73-82

Seasonal dynamics of endosymbiotic ciliates and nematodes in Dreissena polymorpha

Alexander Y. Karatayev,^a,* Sergey E. Mastitsky,^b Lyubov E. Burlakova,^a Daniel P. Molloy,^c and Galina G. Vezhnovets^b

a Department of Biology, Stephen F Austin State University, Nacogdoches, TX 75962-3003, USA

b General Ecology Department, Belarussian State University, 4 Skoryna Ave., Minsk 220050, Belarus

c Division of Research and Collections, New York State Museum, Albany, NY 12230, USA

Received 14 January 2003; accepted 5 March 2003

Abstract

We report the results of a two-year study in the Svisloch River (Minsk, Belarus) on the dynamics of infection in Dreissena polymorpha by nematodes and three ciliate species Conchophthirus acuminatus, Ophryoglena sp., and Ancistrumina limnica. Although these endosymbionts were present in most of the samples, their prevalence and infection intensity differed significantly. C. acuminatus and A. limnica infection intensities in both years of the study had a maximum in summer and were positively correlated with water temperature. In contrast, Ophryoglena sp. and nematode infection intensities were considerably lower in summer versus winter and were negatively correlated with temperature. In the first long-term study to monitor the size and reproductive rate of C. acuminatus, we found that mean length was negatively correlated with temperature and that temperature was positively correlated with asexual reproduction, with a peak of cell division in April as water temperatures increased.

Keywords: Endosymbiont; Zebra mussel; Belarus; Conchophthirus acuminatus; Nematode; Ancistrumina limnica; Commensal; Ophryoglena sp.

* Corresponding author. Fax: + 1-936-468-2056.

E-mail addresses: akaratayev@sfasu.edu (A.Y. Karatayev), sergmast@tut.by (S.E. Mastitsky), Iburlakova@sfasu.edu (L.E. Burlakova), dmolloy@mail.nysed.gov (D.P. Molloy).