Seasonal dynamics of Bythonomus lemani and Bothrioneurum vejdovskyanum (Oligochaeta, Annelida) in relation to environmental variables

• Published in: Biológia 2006-10, Vol.61 (5), p.517-523
• Main Authors: Schenkova, Jana, Helesic, Jan, Jarkovsky, Jiri
• Format: Article
• Language: English
• Subjects: Annelida; aquatic Oligochaeta; Bothrioneurum vejdovskaynum; Bothrioneurum vejdovskyanum; Bythonomus lemani; Freshwater; Lumbriculidae; Oligochaeta; seasonal dynamics; time series analysis; Tubificidae
• ISSN: 0006-3088; 1336-9563
• DOI: 10.2478/s11756-006-0085-x

The seasonal dynamics of Bythonomus lemani (Lumbriculidae) were studied for the first time and the knowledge of Bothrioneurum vejdovskyanum (Tubificidae) was extended based on four quantitative samples of oligochaetes taken monthly in the Rokytná River (Czech Republic) during a two-year study (April 1999–April 2001). The influence of water temperature, velocity, depth, discharge, pH, conductivity, dissolved oxygen amount and biochemical oxygen demand (BOD) on their life cycles was evaluated. Habitat preferences of the juvenile and adult stages were recorded. Time series analysis was used to determine the worm densities, seasonality and trends. For Byth. lemani one distinct reproduction cycle per year was found and this was regulated by temperature, while Both. vejdovskyanum showed a one-year cycle not significantly dependent on measured environmental variables. The overall trend was an increase in density for Byth. lemani and a decrease in density for Both. vejdovskyanum. Byth. lemani showed a significant negative correlation between the trend of its density and BOD concentration.