Communicating editor: D. Fujita.
Impacts of differential consumption by the grazing fish, Plecoglossus altivelis, on the benthic algal composition in the Chikuma River, Japan
Article first published online: 19 JUL 2006
Volume 54, Issue 2, pages 94–98, June 2006
How to Cite
Abe, S.-i., Kiso, K., Katano, O., Yamamoto, S., Nagumo, T. and Tanaka, J. (2006), Impacts of differential consumption by the grazing fish, Plecoglossus altivelis, on the benthic algal composition in the Chikuma River, Japan. Phycological Research, 54: 94–98. doi: 10.1111/j.1440-1835.2006.00413.x
- Issue published online: 19 JUL 2006
- Article first published online: 19 JUL 2006
- Received 23 August 2005; accepted 23 October 2005.
- benthic algal assemblage;
- differential consumption;
- grazing fish;
- upright filamentous cyanobacteria
Grazing effects of ayu, Plecoglossus altivelis Temminck et Schegel, on the benthic algal assemblages were investigated in the Chikuma River, Japan. Comparison of the algal composition on boulders with and without intensively grazed patches indicated that fish grazing decreased the abundance of diatoms and prostrate filamentous cyanobacteria and caused upright filamentous cyanobacteria to predominate. Differential consumption by ayu was estimated by comparing the relative abundance of algae in the stomach contents of ayu and that in the algal assemblages within the grazed patches. The results showed that ayu consumed the prostrate filamentous cyanobacteria proportionally to their abundance, whereas they ingested diatoms and the upright filamentous cyanobacteria in a larger and lower quantity, respectively, than that expected from their abundance. Differential consumption would involve the change in the algal composition toward the predominance of upright filamentous cyanobacteria under fish grazing conditions.