Feeding responses of the gastropod Crepidula fornicata to changes in seston concentration

摘要: We investigated the response of suspension-feeding activity prosobranch gastropod Crepidula fornicata (L.) to changes in seston abundance and composition, characteristic natural particle variability experienced by organisms as a consequence tidal resuspension. The experimental conditions were characterized concentrations (12.2 196.0 mg 1 -1 ) inversely related organic content particulate matter (56 6%). fraction was composed 2 benthic diatoms, Entomoneis pseudoduplex (Smith) Nitzschia aurariae (Cholnoky). Inorganic 3 μm diameter kaolinite particles. functional unit used for determination ecophysiological responses chain 6 individuals with mean dry tissue weight 1.05 g. efficiency retention function size increased increasing from 4 (equivalent spherical diameter). Above μm, all particles cleared suspension 100% efficiency, but efficiencies smaller significantly declined loads. A constant clearance rate (CR) found throughout range, 0.76 ± 0.05 h g (±SE). Filtration linearly concentration minimum value 10 maximum 42.8 at highest concentration. total biodeposition (sum pseudofaeces faeces) followed similar linear trend, an increase 3.8 41.6 Absorption very stable range suspended tested 4.9 0.5 It not possible ascertain pre-ingestive selection, even though biodeposits diet similar. low small inorganic high loads sole mechanism that clearly identified this study counteracting food dilution material, through enrichment filtered matter. absence selection C. would physiological significance process turbid environments.