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Dr. Craig Cary's Abstracts
A microencapsulation technique for
introducing pure compounds in zooplankton diets Abstract
Sodium alginate microcapsules have low permeability, high digestibility, and are specifically suited as artificial food particles for zooplankton. The microcapsules may be used to introduce pure compounds into zooplankton diets and to study the biochemical fate of those compounds. We encapsulated a highly labile molecule Chl a, and traced it and its principal degradation products in zooplankton grazing experiments. Chlorophyll was not degraded or lost during the encapsulation procedure and remained stable for at least 6 d at 4øC in the dark. The microcapsules were ingestible and digestible to female Calanus pacificus, and fecal pellets were formed at normal rates, 40 60 min after ingestion. Two quantitative feeding experiments were conducted with pure chlorophyll. The mean loss of ingested pigment was 85.9%(ñ7.2%) and 76.1% (ñ6.1%). In the second experiment, we analyzed the medium to determine if any chlorophyll may have gone into solution; <2% of the total "lost" chlorophyll went into solution. We conclude that a significant amount of ingested Chl a is degraded into non-fluorescent compounds during passage through copepod guts. |
