Influence of algal concentration and temperature on the filtration rate of Mytilus edulis |
| |
Authors: | E H Schulte |
| |
Institution: | 1. Laboratorio per lo Studio della Contaminazione Radioattiva del Mare, CNEN-EURATOM, Fiascherino, La Spezia, Italy
|
| |
Abstract: | The filtration rates of Mytilus edilis (=galloprovincialis; 40 mm) were determined in relation to food concentration and temperature, using pure suspensions of the unicellular alga Platymonas suecica in concentrations ranging from 3x105 cells/l to 1.5x108 cells/l. The rate of filtration (ml/h/mussel) generally decreased as cell concentrations increased, and dropped to low values when concentrations above 5x107 cells/l were supplied. The amount of water swept clear varied continuously, and noticeable differences in the filtration activity of M. edulis were observed over short time intervals (5 min). Fluctuations of filtered volumes per unit time were greater with lower than with higher concentrations of algae. The influence of temperature on filtration activity was highest between 5°–15°C and 25°–30°C. A temperature increase from 15° to 25°C resulted in only a slight increase in filtration rate. At 5° and 30°C, filtration dropped to very low values, namely 350 and 100 ml/h, respectively. The temperature coefficients for the filtration rates of M. edulis were determined as: Q10 (5° to 15°C)=4.96; Q10 (10° to 20°C)=1.22. The amount of algae cells ingested per mussel per hour is directly related to food concentration. The maximum number of cells filtered/mussel/h in an algal suspension of 70x106 cells/l was 21.5x105 cells/h. Cell concentrations of up to 40x106 cells/l were swept clear without producing pseudofaeces. The critical cell density for M. edulis was reached at algal concentrations of 70 to 80x106 cells/l. Above these concentrations no normal filtration activity was observed. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|