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Abstract
Gulnihal Ozbay. 2007. Comparison of filtration of various size
oysters (Crassostrea virginica).
JEMREST 3:59-73
DOI: 10.4029/2007jemrest3no14
This
study assessed the possible differences in clearance rates and particle removal
efficiency of various size classes of Eastern oysters fed with 5x104cells/mL Tetraselmis chui (strain PLY429) diet. Laboratory experiments on the
filter-feeding activity of various sized oysters (Small: 8.91 ± 1.74g, Medium: 53.52 ± 8.11g, Large: 120.30 ± 22.81g, Extra-Large: 195.08 ± 17.07g, and Various: 9.02 to 152.73g) were studied
at intervals over a 4 hour period. The
results from this study indicate differences (P <” 0.05) in their clearance rates per gram oyster
throughout the time intervals.
Clearance rates from small size oysters were relatively higher during
the first three hours of sampling.
Medium size oysters filtered particles at relatively higher rates than
large and extra large size oysters during the first three hours of sampling
but at lower rates than small oysters.
Oysters in the various size classes showed relatively consistent
filtration during the first three hours of sampling. The small oysters decreased their feeding
rate gradually after the first hour while the medium, large, extra-large, and
various groups increased their feeding rates over 4 hour sampling
period. This study supports the
findings of our previous research, in which higher filtration activity
occurred in smaller oysters and more variable filtration activity was
observed in larger oysters. Smaller oysters also demonstrated more
predictable feeding patterns in both studies.
Other studies have demonstrated that smaller oysters have smaller
somatic reserves and smaller processing capacities resulting in a feeding
pattern that is much more predictable, as supported by the results of these
studies. Through these feeding
studies, we may assist resource managers in finding habitat suitable for
oyster growth and spawning. It may be
advisable to address size class selective feeding when considering oyster
culture and restoration projects.
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