May Meeting - Presenter and Topic
Meeting is tomorrow night.
Speaker: Barrett Christie
Aquarium Supervisor
The Dallas Zoo and Children's Aquarium at Fair Park
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Presentation: ?Water Quality Considerations and Life Support System Design for Cephalopods?. Covering cephalopod water quality requirements in relation to their unique physiology. Presented at the Aquality II Water Quality Symposium.
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Abstract: The captive management of cephalopods necessitates the maintenance of water quality
within precise ranges. Cephalopods have a microvillus epidermis that is one cell layer thick and
contains many pores, increasing the overall surface area. The increased surface area and
permeability make cephalopods highly sensitive to the chemistry and bacterial load of
surrounding water. In addition to an inherent chemical sensitivity, cephalopods also possess
increased metabolic rates; as much as two to three times higher than teleost fishes. As such,
cephalopods produce increased amounts of nitrogenous wastes (NH3/NO2) which must be
oxidized by nitrification in closed systems below 0.10 mg/L. Cephalopods are also highly
sensitive to nitrate concentrations well below acceptable thresholds for fishes (50-80 mg/L).
Thus, life support strategies must address these particular aspects of water quality to ensure
animal welfare. Decades of laboratory culture have provided insights into the most effective
filtration components to meet the unique demands of these animals. Life support systems in
laboratories and public aquaria typically employ mechanical filtration followed by foam
fractionation, biofiltration, activated carbon, and sterilization before returning water to the
exhibit. Filtration strategies designed with the unique physiology of cephalopods in mind are
best suited to meet their stringent needs for water quality and facilitate good husbandry.
