Feeding By U. Båmstedt, D. J. Gifford, X. Irigoien, A. Atkinson and M. Roman

Contents Questions Comments and corrections New protocols Back to the main page

Contents 8.1 Introduction 8.2 Feeding mechanisms of zooplankton 8.3 Expression of zooplankton feeding rates and common conversion factors - Clearance rate (F) - Ingestion rate (I) - Daily ration (DR) - Conversion between units of mass and energy 8.4 Microzooplankton - Methodological approaches - Indirect methods to measure assemblage grazing - Correlation of natural consumer-prey cycles - Extrapolation of laboratory rates to the field - The pigment budget - Acid lysozyme assay - Direct methods to measure per capita grazing rates - Food tracers: inert particles - Food tracers: prey cells - Food tracers: radioisotopes - Food vacuole contents - Prey removal - Direct methods to measure assemblage grazing rates - Sea water dilution method - Working procedures for the sea water dilution method - Size fractionation method - Metabolic inhibitor method 8.5 Meso- and macrozooplankton - Empirical relationships - Field investigations on gut fluorescence - Sampling - Preparation for analysis - Gut clearance coefficient - Sorting animals - Extraction - Pigment analysis - Transformation to carbon - Pigment destruction - Working procedures for the gut fluorescence method - Equipment - Supplies - Procedure - Measurement and calculations - Comments and special precautions - Gut contents of field sampled consumers - General procedures - Special case: copepod mandibles in stomach contents - Digestion - Methods based on budgets of material or energy - Growth - Egestion - Excretion - Respiration - Assimilation efficiency - Measurement of assimilation efficiency: direct measurements - Measurement of assimilation efficiency: indirect calculation - Measurement of assimilation efficiency: ratio methods - Non-homogeneous food material - Food selectivity - Sloppy feeding - Losses from faecal material - Absorbance of IT in the digestive tract - Production of non faecal material mixed with faeces - Ash-ratio method - Chlorophyll –ratio method - Silica-ratio method - Radioisotope tracers - Methodological comparisons - Working procedure for laboratory experiments with radioisotopes - Working procedure for field experiments - Food removal methods - Bottle effects during incubations - Sloppy feeding - Estimates of community grazing rate - Working procedures with food removal methods - Collection of zooplankton - The food source - Experiments - Sub-sampling - Microscopic examination of sub-samples - Feeding rate calculations - Use of film and video to study feeding behaviour - Biochemical indices - Working procedures for measurement of digestive enzyme activity - Amylase - Trypsin 8.6 Difficulties with specific zooplankton groups - Stomach contents from field samples - Laboratory experiments 8.7 Omnivory - A general method to estimate omnivory - Collection of consumers - Collection and handling of water - Sample collection, processing and analysis - Data analysis - Gut fluorescence and experimental egg production - Gut fluorescence and egestion rate - A method to estimate the importance of copepod prey for predators 8.8 Factors regulating feeding rate - Abundance of food items - Functional response. Model I - Functional response. Model II - Functional response. Modified model II - Functional response. Model III - Design of functional response experiments - Calculation curve fits in functional response experiments - Size of food items - Turbulence - Consumer body size - Palatability / toxicity of food organisms - Physical environmental factors - Temperature - Light - Spatial constraints 8.9 Predation behavioural models 8.10 Concluding remarks 8.11 Acknowledgments 8.12 References Top of the Document Questions Top of the Document Comments and corrections Top of the Document New Protocols Top of the Document