1] (fully open mussels) to the time when the mean valve gape was reduced to 50% of the maximum registered during the preceding steady-state period.
Initially the mean valve gape decreased nearly linearly, but the closing response was faster in fed than in starved mussels.
The observed valve gape responses to presence/absence of algal cells in the ambient water shows that the valve opening/closure responses are strongly influenced by the preceding feeding conditions.
The duration of the opening response (defined as the time from readdition of algal cells after a short period of valve closure caused by stoppage of the dosing pump until the mean valve gape had increased to maximum) is shown on Figure 8.
1] responded to a slight reduction in the algal concentration by a nearly immediate reduction in valve gape (Fig.
were never exposed to such high current speeds reported to affect the valve gape of mussels (see e.
As stated by Riisgard (2001b) the valve-closing phenomenon, which has also been clearly demonstrated in the present work, represents a physiological adaptation to filter feeding in extremely meager situations, when a reduced valve gape reduces the metabolism of the mussel (Jorgensen et al.
1] stimulate the mussels to keep their valves wide open, whereas lower near-bed concentrations cause valve closure, or reduced valve gape.
The effects of velocity and seston concentration on the exhalant siphon area, valve gape and filtration rate of the mussel, Mytilus edulis.